Thread: Overhead door reverse failure

Greetings from Ohio,
During an inspection today I noticed the overhead doors were missing the photo-eyes. I then proceeded to open and then close the door, while standing inside and extending my forearms with bent elbows at waist height to allow the door to come down on my forearms to meet resistance and hopefully return up again. EPIC FAILURE! At the point of resistance at which a door would return up, the upper panel where the opener ties in completely came apart, also damaging the upper panel.
Am I at fault? How would you handle this situation? Both the potential buyer and homeowner witnessed the ordeal. Come to find out the photo-eyes were mounted on the ceiling behind the opener.

Thanks a bunch,
Chad Webster

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Door failed under testing - repairs/replacement needed...

It doesn't sound like you did anything out of the ordinary in checking the operability of a standard safety feature for the door and opener. The fact that the motion beam sensors were mounted on the ceiling behind the opener is an indicator alone that the the installation was wrong.

Did the homeowner say if the door or opener were newer? Any pics you can post of the aftermath?

Your testing methods aren't correct. That outstretched arm test has bested many inspectors and busted many doors.

You should have seen the photo eyes before operating the motor (they weren't missing). Although not a sure thing, that may have provided clues to "be on the look out" for more issues. The upper panel may have had visible clues of damage, improper installation, or a missing support brace.

Did you operate the door manually first?

Dom.

I'm with Dom. You didn't test the door properly.
Regardless how the sensors were mounted, you didn't test it correctly.
Pay for the repair and consider it a "stupid tax" (as Dave Ramsey likes to call it).

I normally don't think an inspector is responsible if something fails during normal operation. But, knowing that the sensors were not in place would be enough for me to question the installation.

I have also learned from experience that if metal doors do not have proper reinforcing at the top panel they can fail. When sensors are not present and if the door is reinforced I put a little resistance against the door as it closes. If it does not reverse with relatively light pressure I suggest adjustment and then testing.

If a company installed the opener that way, the owner should go after them. It is not only against manufacturer's requirements to not install the sensors 4-6 inches above the floor, it also violates federal laws.

I hate to agree with my brethren, but you screwed up. The method you used is not approved by any manufacturer or their garage door association for testing any door or opener. It sounds like an old door and opener and more than likely did not have the reversing feature. Many inspectors have fallen prey to this method of testing and have watched the door buckle and in some cases fall.

I only swing my foot in front of the eyes and I test the doors balance. I do not test the pressure reversing feature for the very reason you discovered. The proper way to test the reversing feature is with a 2x4 on the ground.

Chad,
Without seeing the installation of the opener and the door my thought is that you are not at fault. Your location for testing can have some effect on extent of damage on failure of operation functions. But the door properly installed and adjusted will reverse at any point of operation except within the last 1 inch of meeting floor.

Based on what you described my guess is the following.
1) Single panel metal door.
2) No reinforcement on the door at the opener/door connection.
3) Photo-eyes were mounted on the ceiling behind the opener suggest that the opener was new enough to be adjustable for it opening and closing functions.
4) With the eyes on the ceiling the entire installation is suspect. Though I know why they were put there.
5) Door failed to reverse on meeting an obstruction and resulting damage is directly a result of the installation method and adjustment, not the person testing its operation.

The seller/owner is responsible for repairs.

I just happen to have a brochure for garage door openers on my desk, and this is what is says...

Test the reversing feature every month

First, test the balance of the door. If the door is properly balanced, then proceed.

With the door fully open, place a 1-1/2" thick piece of wood (a 2x4 laid flat) on the floor in the center of the door.

Push the transmitter or wall button to close the door. The door must reverse when it strikes the wood.

If the door does not reverse, have it repaired or replaced. Have a qualified individual adjust, repair, or replace the opener or door.

Early in my career if you can call it that I busted a garage window stopping it with my hand. Now I let them go down if they insist on carrying on. It is a subtle thing and I understand why some guys use a roll of paper towels instead of a 2 X 4.
I hate witnesses. Next time you will look before you leap and let it go before it breaks itself.

I bought a piece of glass and fixed the door, with help from the owner, who was good about it.

Well, then I stand corrected and it seems I have been testing this feature incorrectly all along. if the proper way to test this feature is with a piece of wood, that seems like an even more likely way to induce damage to the door. I see garage doors that regularly will not stop with my arm pressure and I can only imagine how many doors might get damaged/bent if I put a solid piece of wood beneath them.

Is the idea behind using a 2x4 to limit the amount of damage to the door if it will not stop since it will be a short travel at that point in how close it is to being fully closed?

Ok gang,
Your insight has been helpful. The method of testing is how I was instructed to use in my certification classes. We were told specifically not to use a 2x4. I did not look for any reinforcement in the upper panel, therefor, I believe I have just learned a lesson the hard way. I would much rather repair the door than my reputation.
Thanks very much,
Your professionalism is much appreciated,
Chad

Chad,
Without knowing all of what you were taught, all doors should reverse at any point that they meet an obstruction with the exception of 1"inch from floor. Conversely they door should also stop if it meets resistance as it opens.

In your case I think it may be more about what you were taught to look for in the door installation. Things that clue you in that provide you with an expectation of some potential operational issue that may cause a failure.

There are several threads that have discussed testing methodology take a look.

Personally, I wait till the door is a bit above knee-high, put my hand (backhanded) under the door and put a little resistance into it - if it hurts my back before the door reverses, I let go and write it up or adjust it myself while showing the new owner how and why it's done...... Just adjusted one yesterday as a matter of fact. Sometimes it's easier to fix something that to spend the time to write it up... JMO.

CHAD
I always open door first and check to see if door hardware is secured-most wood framed doors you will find loose hardware. then I test eye for operation--next I let door come down waist high and use my hands to put resistance on for reversal.if it doesn't work I adjust it and show client how and where to do it. so i don't have to write it up--ljke finding loose cabinet hinges

cvf

Originally Posted by Garry Sorrells

Chad,
Without seeing the installation of the opener and the door my thought is that you are not at fault. Your location for testing can have some effect on extent of damage on failure of operation functions. But the door properly installed and adjusted will reverse at any point of operation except within the last 1 inch of meeting floor.

Based on what you described my guess is the following.
1) Single panel metal door.
2) No reinforcement on the door at the opener/door connection.
3) Photo-eyes were mounted on the ceiling behind the opener suggest that the opener was new enough to be adjustable for it opening and closing functions.
4) With the eyes on the ceiling the entire installation is suspect. Though I know why they were put there.
5) Door failed to reverse on meeting an obstruction and resulting damage is directly a result of the installation method and adjustment, not the person testing its operation.

The seller/owner is responsible for repairs.

But, assuming #2 is correct, then testing the reversing feature is a bed idea.

Two inspectors stating that they "fix things" instead of writing the items up - it is NEVER "easier" to "fix" something than it is to "write it up" ... unless one is a very poor writer ...

Besides that - YOU NOW HAVE THE LIABILITY for "adjusting"/"fixing" it!

If you have insurance - does your insurance company know that you "fix"/"adjust" things?

I bet they would be very interested in knowing just what you are doing besides "inspecting" because they are the ones who YOU think will write the big check, but ... they will find it much "easier" to tell you - 'Sorry, YOU "fixed"/"adjusted" it, now YOU bought it, and we (the insurance company) are out of the picture.' 'Oh, and that classic Mustang which the door fell on and crushed ... that is now yours and you get to buy another one for the owner.'

What if the garage door failed to properly reverse and a person was crushed - how are you going to explain it to the judge that 'all you did was a minor adjustment' ... yeah, and that minor adjustment just killed someone.

I can't believe some of the things I am reading here lately.

Originally Posted by Scott Patterson

I hate to agree with my brethren, but you screwed up. The method you used is not approved by any manufacturer or their garage door association for testing any door or opener. It sounds like an old door and opener and more than likely did not have the reversing feature. Many inspectors have fallen prey to this method of testing and have watched the door buckle and in some cases fall.<br>
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I only swing my foot in front of the eyes and I test the doors balance. I do not test the pressure reversing feature for the very reason you discovered. The proper way to test the reversing feature is with a 2x4 on the ground.

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I agree with Scott: I too only swing my foot a between the eyes. The door should stop and then reverse. The pressure test should be done with a piece of 2x4, but I do not do that test. I have a narrative in my reports saying which tests are done, which ones are not and why.

2) No reinforcement on the door at the opener/door connection.

Originally Posted by Mark Reinmiller

But, assuming #2 is correct, then testing the reversing feature is a bed idea.

Precisely my point. You have to first inspect the entire door installation and the door itself before you touch anything. Don't care if you think that the owner has been using it for 20 years without any issues. Only after inspecting the installation and finding no flaws that would effect the operation would you then engage the electric opener and perform any other testing of operations.

More to the point for the no reinforcement issue, if the door should have it and it doesn't then I would not operate it with the opener. Only by hand. If the owner is present then have them demonstrate the operation and the monthly testing that they are performing.

Normally there are some telltale signs that non correctly reinforced doors have been stressed, but you have to look and be able to recognize those signs.

Originally Posted by Nick Ostrowski

Is the idea behind using a 2x4 to limit the amount of damage to the door if it will not stop since it will be a short travel at that point in how close it is to being fully closed?

No, but any damage will likely be less for that reason. With the door nearly vertical and nearly at the end of its travel - at 1-1/2" above the floor the door is almost ready for the operator to push the top tight to the wall as the bottom of the door closes against the floor - there shouldn't be much room for damage with a properly placed 2x4 and a door which has first been inspected to make sure the stiffener/brace is properly present and that there are not other signs of impending failure.

The door is not intended to try to crush the 2x4, the 2x4 is intended to provide a good, solid, repeatable, resistance at 1-1/2" high above the floor, and the door is intended to reverse on contact with the 2x4 ... not while one watches to see if the door can crush the 2x4 .

Of course, though, I always looked to see how high the track would bow upward when the opener was trying to crush the 2x4 ... yeppers, that one did not automatically reverse either nor could it crush the 2x4 either - something must be wrong with it ...

Originally Posted by chad webster

Greetings from Ohio,
During an inspection today I noticed the overhead doors were missing the photo-eyes. I then proceeded to open and then close the door, while standing inside and extending my forearms with bent elbows at waist height to allow the door to come down on my forearms to meet resistance and hopefully return up again. EPIC FAILURE! At the point of resistance at which a door would return up, the upper panel where the opener ties in completely came apart, also damaging the upper panel.
Am I at fault? How would you handle this situation? Both the potential buyer and homeowner witnessed the ordeal. Come to find out the photo-eyes were mounted on the ceiling behind the opener.

Thanks a bunch,
Chad Webster

Regardless of the method used to test the reversing operation, it is hard to see how you are liable, but then risk management in most jurisdictions is litigation averse so they may pay damages anyway. It is annoying however. I shudder to think what the result would have been if an elderly person was bent over & hobbling thru that door way while it was in operation. Likely the door would have been damaged just as it was in your test, but an elder would most likely also have been put on the ground with injuries. Lawyers tend to muddy the clearest water & like it or not your jurisdiction may end up settling by paying the cost of repairs.

I would have to say my rub with this accepted testing method is it does not replicate a real world scenario. If the bottom of the door is only 1.25" away from the garage floor, anything in it's way at that point is not going to be of any great value. A real world scenario is a car parked halfway out of the garage and somebody accidentally sends the door down. Yes, the door does need to be properly installed to begin with but the accepted testing method does not accurately depict how the door and feature will perform under a real world situation.

Originally Posted by Nick Ostrowski

I would have to say my rub with this accepted testing method is it does not replicate a real world scenario.
.
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Yes, the door does need to be properly installed to begin with but the accepted testing method does not accurately depict how the door and feature will perform under a real world situation.

The 2x4 test accurately represents the tests required for the manufacturers.

Do you want to use a standard recognized test or a test which has not real meaning?

If the door reverses on contact with the 2x4, that is the test for the standard recognized auto reverse feature, and ... it is likely shown depicted in the form of a drawing on a label on every garage door and has text stating how the test is done. I am not sure, but I think that label is required to be placed on the garage door which has an operator attached to it.

Do it the way that label says. We do not seem to have a problem referring to manufacturer's installation and operating instructions for other items ... why do we have it for garage door operators, especially when it is a larger item and has a great potential for killing or injuring someone?

Originally Posted by Nick Ostrowski

I would have to say my rub with this accepted testing method is it does not replicate a real world scenario. If the bottom of the door is only 1.25" away from the garage floor, anything in it's way at that point is not going to be of any great value. A real world scenario is a car parked halfway out of the garage and somebody accidentally sends the door down. Yes, the door does need to be properly installed to begin with but the accepted testing method does not accurately depict how the door and feature will perform under a real world situation.

I am not defending the accepted test procedure. I have not tried it, but suspect an improperly braced door could be damaged if tested that way. Of course, whoever came up with the test probably did not test door under real word conditions.

The point of the safety reverse feature is not to protect your car, but your kids. That is why the sensors are supposed to be 4 to 6 inches above the floor.

OK, then what is the purpose of the mechanical reverse feature? The motion beam sensors (to me) are for kids. What is the mechanical reverse feature for? What is it supposed to save/prevent?

Originally Posted by Nick Ostrowski

OK, then what is the purpose of the mechanical reverse feature? The motion beam sensors (to me) are for kids. What is the mechanical reverse feature for? What is it supposed to save/prevent?

Important redundancy. If I am not mistaken, the auto reverse / obstruction feature came first and the sensor beam was added to the mix at a later date. Belt and suspenders to prevent entrapment.

Originally Posted by Nick Ostrowski

OK, then what is the purpose of the mechanical reverse feature? The motion beam sensors (to me) are for kids. What is the mechanical reverse feature for? What is it supposed to save/prevent?

The reverse on contact is an "Anti-entrapment" feature and offers additional safety that the photo beams does not provide.
Photo beams are 4"-6" above the floor. An arm or leg can be under the door yet not trip the photo beam.

Originally Posted by Mark Reinmiller

......... Of course, whoever came up with the test probably did not test door under real word conditions.

The point of the safety reverse feature is not to protect your car, but your kids. That is why the sensors are supposed to be 4 to 6 inches above the floor.

Originally Posted by Nick Ostrowski

OK, then what is the purpose of the mechanical reverse feature? The motion beam sensors (to me) are for kids. What is the mechanical reverse feature for? What is it supposed to save/prevent?

The criteria for the operator functions were developed by UL and the Consumer Product Safety Commission. The UL criteria was then incorporated into federal requirements.

The UL looked at several situations that may (actually have) occurred when they developed the reversal requirements (specifications). These were two real world situations that occurred.
a) Door closing and encountering someone on a ladder.
b) Door closing and encountering someone standing in opening.
For a and b above the person being struck by the door could then collapse where the door would continue down to crush them if it did not reverse. If the door only were to stop it could cause enough pressure and restriction to cause death. Or as in one case the person was trapped and unable to extricate themselves. In that case it was a long time before someone found the trapped person. So there was a 1" requirement created that they thought would cover everything and still allow the door to compress the bottom seal effectively.

After the reversal requirements were created they found that there were injuries to children from being crushed (compressed) by the door before it did reverse. {{{ Remember there is no requirement for amount of pressure (PSI) exerted by the door, just time of contact before reversal (2 seconds).}}} So the UL came up with the sensor beam that stops the door if there is something on the floor such as a child, old frail people or HIs interrupting the beam.

The use of a 2x4 (actual 1.5" by 3.5") block became excepted as a testing mechanism, since it was a commonly available item that came close to the actual UL testing criteria measurement. The block on the floor creates a testing condition that limits the potential liability of personal injury. The liability is what so many fret about to a paranoid extreme.

In the real world installers test the operator reverse function at around 3 or 4 feet from floor. It is a relatively passive creation of a presumed obstruction that may occur. It is not a Hulk Hogan wrestling match with the door.

Now let me say that the most of the door operators on the market have been redesigned and they have an entirely different system that causes the motor to reverse. In addition the operators have a different method to set the travel distances of the door operation, travel limits. Some manufactures refer to a self learning function of the operator. Takes some of the fun out of installation and maintenance.

As a side note: don't forget older doors still have manual adjustments that effect operator functions which will cause damage to the door is not correct.

If memory serves me correct, the door is supposed to reverse when it encounters no more than 15 pounds of resistance.

Although it is not the correct test method, that is why I use my hands, because I can judge when the resistance seems to be too much and let go before the door breaks (this assumes the door is properly braced). If anything looks questionable, I don't test that feature.

I'm not saying my method is correct, it is just what I have done for the past 30 years.

Originally Posted by Mark Reinmiller

If memory serves me correct, the door is supposed to reverse when it encounters no more than 15 pounds of resistance.

Although it is not the correct test method, that is why I use my hands, because I can judge when the resistance seems to be too much and let go before the door breaks (this assumes the door is properly braced). If anything looks questionable, I don't test that feature.

I'm not saying my method is correct, it is just what I have done for the past 30 years.

Mark,
The discussion I hope has been about an overhead sectional vertical tracked door, else it is apples and oranges type of discussion. Also specifically discussing the anti entrapment function of the operator itself and not a secondary sensor. Therefore; No, there is no PSI involved in the reversal requirement on an over head sectional vertical tracked door operator. It is a time on contact function to meet requirements.

I contacted the UL for a clarification to the question of PSI involved with the requirements that must be met with a door operator.
A portion of an email 4/21/12 from: UL, Jim Miller, P.E. Senior Project Engineer

Residential garage door operators are also required to be provided with inherent entrapment protection (in addition to the external entrapment protection), where the door is required to reverse within 2 s a minimum of 2 in. But there are currently no requirements for the amount of the force that is allowed, just needs to reverse.


Some of the actual nitty gritty for those interested:
http://www.gpo.gov/fdsys/pkg/CFR-201...2-part1211.pdf

§ 1211.7 Inherent entrapment protection requirements.
(a)(1) Other than for the first 1 foot (305mm) of door travel from the full upmost position both with and without any external entrapment protection device functional, the operator of a downward moving residential garage door shall initiate reversal of the door within 2 seconds of contact with the obstruction as specified in paragraph (b) of this section.



The 15LB is from:
Underwriters Laboratories ( UL )
UL 325 Sec. 36
36 Edge Sensors
36.1 Normal operation test
36.1.1 When installed on a representative residential door edge, an edge sensor shall actuate upon the application of a 15 lbf (66.7 N) or less force in the direction of the application. For an edge sensor intended to be used on a sectional door, the force is to be applied by the longitudinal edge of a 1-7/8 in (47.6 mm) diameter cylinder placed across the sensor so that the axis is perpendicular to plane of the door. For an edge sensor intended to be used on a one piece door, the force is to be applied so that the axis is at an angle 30 degrees from the direction perpendicular to the plane of the door.

Then it shows up in:
§ 1211.12 Requirements for edge sensors.
(a) Normal operation test. (1) When installed on a representative door edge, an edge sensor shall actuate upon the application of a 15 pounds (66.7 N) or less force in the direction of the application. For an edge sensor intended to be used on a sectional door, the force is to be applied by the longitudinal edge of a 17⁄8 inch (47.6 mm) diameter cylinder placed across the switch so that the axis is perpendicular to the plane of the door. For an edge sensor intended to be used on a one piece door, the force is to be applied so that the axis is at an angle 30 degrees from the direction perpendicular to the plane of the door. See figure 6.
(2) With respect to the test of paragraph (a)(1) of this section, the test is to be repeated at various representative points of the edge sensor across the width of the door.
(3) Exception: The edge sensor need not be sensitive to actuation two inches (50.4mm) or less from each end of the intended width of the door opening.


§ 1211.13 Inherent force activated secondary door sensors.
(a) Normal operation test. (1) A force activated door sensor of a door system installed according to the installation instructions shall actuate when the door applies a 15 pound (66.7 N) or less force in the down or closing direction and when the door applies a 25 pound (111.2 N) or less force in the up or opening direction. For a force activated door sensor intended to be used in an operator intended for use only on a sectional door, the force is to be applied by the door against the longitudinal edge of a 17⁄8 (47.6 mm) diameter cylinder placed across the door so that the axis is perpendicular to the plane of the door. See Figure 6 of this part. The weight of the door is to be equal to the maximum weight rating of the operator.

This has been a topic of several other threads which also have gone "hot". There are links to code, federal guidelines, and manufacturer's instructions in those other threads. Some manufacturers use the "hand" test to set the obstruction sensor. But none of the manufacturers recommend grabbing the door around waist level.

While you didn't use a recommended opener test, you still found a defect. Obstructions can occur at any height. Tell the parties of this transaction that you found a defect, possibly prevented damage to that classic Mustang, or worse, injury to a kid who left his/her bicycle in the door path. The seller incorrectly installed or failed to correct the installation of the opener, and that is where the fault lies.

For the future, revise your testing methods.

Originally Posted by Garry Sorrells

Mark,
The discussion I hope has been about an overhead sectional vertical tracked door, else it is apples and oranges type of discussion. Also specifically discussing the anti entrapment function of the operator itself and not a secondary sensor. Therefore; No, there is no PSI involved in the reversal requirement on an over head sectional vertical tracked door operator. It is a time on contact function to meet requirements.

I contacted the UL for a clarification to the question of PSI involved with the requirements that must be met with a door operator.
A portion of an email 4/21/12 from: UL, Jim Miller, P.E. Senior Project Engineer

Residential garage door operators are also required to be provided with inherent entrapment protection (in addition to the external entrapment protection), where the door is required to reverse within 2 s a minimum of 2 in. But there are currently no requirements for the amount of the force that is allowed, just needs to reverse.


Some of the actual nitty gritty for those interested:
http://www.gpo.gov/fdsys/pkg/CFR-201...2-part1211.pdf

§ 1211.7 Inherent entrapment protection requirements.
(a)(1) Other than for the first 1 foot (305mm) of door travel from the full upmost position both with and without any external entrapment protection device functional, the operator of a downward moving residential garage door shall initiate reversal of the door within 2 seconds of contact with the obstruction as specified in paragraph (b) of this section.



The 15LB is from:
Underwriters Laboratories ( UL )
UL 325 Sec. 36
36 Edge Sensors
36.1 Normal operation test
36.1.1 When installed on a representative residential door edge, an edge sensor shall actuate upon the application of a 15 lbf (66.7 N) or less force in the direction of the application. For an edge sensor intended to be used on a sectional door, the force is to be applied by the longitudinal edge of a 1-7/8 in (47.6 mm) diameter cylinder placed across the sensor so that the axis is perpendicular to plane of the door. For an edge sensor intended to be used on a one piece door, the force is to be applied so that the axis is at an angle 30 degrees from the direction perpendicular to the plane of the door.

Then it shows up in:
§ 1211.12 Requirements for edge sensors.
(a) Normal operation test. (1) When installed on a representative door edge, an edge sensor shall actuate upon the application of a 15 pounds (66.7 N) or less force in the direction of the application. For an edge sensor intended to be used on a sectional door, the force is to be applied by the longitudinal edge of a 17⁄8 inch (47.6 mm) diameter cylinder placed across the switch so that the axis is perpendicular to the plane of the door. For an edge sensor intended to be used on a one piece door, the force is to be applied so that the axis is at an angle 30 degrees from the direction perpendicular to the plane of the door. See figure 6.
(2) With respect to the test of paragraph (a)(1) of this section, the test is to be repeated at various representative points of the edge sensor across the width of the door.
(3) Exception: The edge sensor need not be sensitive to actuation two inches (50.4mm) or less from each end of the intended width of the door opening.


§ 1211.13 Inherent force activated secondary door sensors.
(a) Normal operation test. (1) A force activated door sensor of a door system installed according to the installation instructions shall actuate when the door applies a 15 pound (66.7 N) or less force in the down or closing direction and when the door applies a 25 pound (111.2 N) or less force in the up or opening direction. For a force activated door sensor intended to be used in an operator intended for use only on a sectional door, the force is to be applied by the door against the longitudinal edge of a 17⁄8 (47.6 mm) diameter cylinder placed across the door so that the axis is perpendicular to the plane of the door. See Figure 6 of this part. The weight of the door is to be equal to the maximum weight rating of the operator.

1211.13 diffuses secondary reversing sensors and 15 pounds of force. As far as I recall the photo eyes force sensors and 2 second reverse are required. I think the info in the email is incomplete.

Originally Posted by Mark Reinmiller

1211.13 diffuses secondary reversing sensors and 15 pounds of force. As far as I recall the photo eyes force sensors and 2 second reverse are required. I think the info in the email is incomplete.

Door operator (motor) is primary § 1211.7 , with no other sensors on door edge, which is the 2 second contact criteria to reverse with no consideration of amount of force (pressure,PSI) applied at contact point by the operator.

A secondary sensor such a edge sensor, on bottom edge, is what the 15lb is referring to and works differently than the operator sensor. § 1211.13 Inherent force activated secondary door sensors.

The email was directed at the standard vertical sectional door operator and if there was any consideration by UL on the PSI excreted on contact to trigger reversal of the door. PSI was not a consideration on the UL reversal requirements that formed the basis for primary operator sensor.

The photo eyes are separate having no connection to door sensor requirement and are required with either § 1211.13 or § 1211.7

Originally Posted by Garry Sorrells

The email was directed at the standard vertical sectional door operator and if there was any consideration by UL on the PSI excreted on contact to trigger reversal of the door. PSI was not a consideration on the UL reversal requirements that formed the basis for primary operator sensor.

I understand what the original email was about. My point, if I was not clear, is that even with the photo eye sensors, door openers still have a mechanical reversing feature and this should reverse the door at 15 pounds of force (not PSI).

Originally Posted by Mark Reinmiller

I understand what the original email was about. My point, if I was not clear, is that even with the photo eye sensors, door openers still have a mechanical reversing feature and this should reverse the door at 15 pounds of force (not PSI).

Leaving the photo eye sensor out of discussion. Photo eye are add on accessories to the door installation and operator and operates independently.

Yes and no. Apples and oranges on what happens at the bottom edge of the door.

**Yes - The door operator(motor) with no other edge sensor installed on the door does have a reversing feature (internal mechanism/design) that is integrated into the operator motor that senses the non movement of the door. It is required to reverse the door when the motor fails to move the door for 2 seconds. There is no criteria of force used or exerted by the motor on the door by the motors arm connection to the door. There is no sensor on the door edge. It is all about the actual operator (motor) design and how it functions. The specific technical design that is used in the motor circuit board that determines that door is not moving is not specified by UL. Just that the operator (motor) recognize it is not moving the door and then in 2 seconds or less reverse the motor direction and thus reverse the door.

Lets approach it in a different way. If you were to block the top roller in the track of the 2nd door panel from the top. The roller being prevented from movement will cause the door to stop. The motor senses that the door is not moving and will reverse. Nothing is in contact with the bottom edge of the door. For this type of reversal the bottom edge is just another point that the door could be blocked from movement(travel).

**No - The typical garage door does not have an edge sensor (mechanism) built into it. The typical edge sensor is actually added to the door, optional feature. There are two contact strips enclosed in a full length rubber tube that is attached on the bottom edge of the door. When the two contact strips come in contact with each other the result is to trigger a switch that reverses the motor. This attached tube edge is to be activated if
"§ 1211.12 Requirements for edge sensors.
(a) Normal operation test. (1) When installedon a representative door edge, an edge sensor shall actuate upon the application of a 15 pounds (66.7 N) or less force in the direction of the application. For an edge sensor intended to be used on a sectional door, the force is to be applied by the longitudinal edge of a 17⁄8 inch (47.6 mm) diameter cylinder placed across the switch so that the axis is perpendicular to the plane of the door. ...." or
"§ 1211.13 Inherent force activated secondary door sensors"


The test is to cause the contact strips to meet with 15lbs of force exerted on them. This is ot occur at 1 7/8 inches from the floor as a minimum measurement. You could also push on the edge sensor at any point of the downward movement of the door and it will require 15 lbs to cause the contact strips to meet and than reverse the door. It is correct that this is not specified as 15 PSI and that PSI is not involved in any of the criteria as a measurement to cause reversal function of the door operator.


Why they chose a cylinder as apposed to a block of wood must have some rational, I can not say for sure. It may be due to typical edge sensor thickness and enclosure design. Making them use a 2" or less outside diameter tube to house the contact strips. Or, distance between the internal contact points if so designed. Before I hear it, contract strips are not the only type of design used on the edge sensors.


It would be interesting for someone to do math to determine the PSI that is exerted on the cylinder as the 15lbs of force is generated. You would have to take into account the deflection of the circuit enclosure over the cylinder. For my part I am to lazy to do that. Definitely would have to break out my physics and calculus books to develop the formula. BUT I would love someone else to do that. Though it would have to be adjusted for different edge sensor designs.

So in a recap.
--Door without an Edge Sensor ( see § 1211.7 ) added to it requires 2 seconds or less of movement at 1" from floor, but a 2x4 wood block that is 1 1/2" thick is also acceptable to do monthly test.

-- Door with an Edge Sensor (see § 1211.12 , § 1211.13 ) added to it requires a maximum 15lb of force to be exerted on a 1 7/8" cylinder located on floor.

Originally Posted by Mark Reinmiller

If memory serves me correct, the door is supposed to reverse when it encounters no more than 15 pounds of resistance.

Although it is not the correct test method, that is why I use my hands, because I can judge when the resistance seems to be too much and let go before the door breaks (this assumes the door is properly braced). If anything looks questionable, I don't test that feature.

I'm not saying my method is correct, it is just what I have done for the past 30 years.

I appreciate all the good technical remarks by my many learned colleagues but Mark hits the "mark" in my opinion. I have tested many, many doors, long before the "eyes" came out and I would never stick a solid object in the path of a moving door. That could cause a lot of expensive unnecessary damage. I always do just as Mark does, I wait until the door is about thigh high and grasp the bottom with one hand. If I can't stop it, its a write up with strong warning not to ignore the condition, but to get a competent technician to fix it. I have never broken a door and I am pretty sure I have not caused any unnecessary alarm. If I can't stop the door then the force of the door would be enough to kill someone's cat or dog or severely injure a child.

- - - Updated - - -

Originally Posted by Mark Reinmiller

If memory serves me correct, the door is supposed to reverse when it encounters no more than 15 pounds of resistance.

Although it is not the correct test method, that is why I use my hands, because I can judge when the resistance seems to be too much and let go before the door breaks (this assumes the door is properly braced). If anything looks questionable, I don't test that feature.

I'm not saying my method is correct, it is just what I have done for the past 30 years.

I appreciate all the good technical remarks by my many learned colleagues but Mark hits the "mark" in my opinion. I have tested many, many doors, long before the "eyes" came out and I would never stick a solid object in the path of a moving door. That could cause a lot of expensive unnecessary damage. I always do just as Mark does, I wait until the door is about thigh high and grasp the bottom with one hand. If I can't stop it, its a write up with strong warning not to ignore the condition, but to get a competent technician to fix it. I have never broken a door and I am pretty sure I have not caused any unnecessary alarm. If I can't stop the door then the force of the door would be enough to kill someone's cat or dog or severely injure a child.

- - - Updated - - -

Originally Posted by Mark Reinmiller

If memory serves me correct, the door is supposed to reverse when it encounters no more than 15 pounds of resistance.

Although it is not the correct test method, that is why I use my hands, because I can judge when the resistance seems to be too much and let go before the door breaks (this assumes the door is properly braced). If anything looks questionable, I don't test that feature.

I'm not saying my method is correct, it is just what I have done for the past 30 years.

I appreciate all the good technical remarks by my many learned colleagues but Mark hits the "mark" in my opinion. I have tested many, many doors, long before the "eyes" came out and I would never stick a solid object in the path of a moving door. That could cause a lot of expensive unnecessary damage. I always do just as Mark does, I wait until the door is about thigh high and grasp the bottom with one hand. If I can't stop it, its a write up with strong warning not to ignore the condition, but to get a competent technician to fix it. I have never broken a door and I am pretty sure I have not caused any unnecessary alarm. If I can't stop the door then the force of the door would be enough to kill someone's cat or dog or severely injure a child.

Garry, Bottom line is that every door opener I have seen constructed since 1993 has photo eyes AND a reversing clutch that is adjustable for force. Forget the edge sensors. I have never seen any. If this is not clear, then look at any opener or instruction manual. The resistance clutch is present in addition to the photo eyes.

Originally Posted by Mark Reinmiller

The resistance clutch is present in addition to the photo eyes.

To put it in the correct order ... the photo eyes are in addition to the motor mechanically/electrically reversing from the door making contact.

The mechanical/electrical reversing came first, the photo eyes came second.

Originally Posted by Jerry Peck

To put it in the correct order ... the photo eyes are in addition to the motor mechanically/electrically reversing from the door making contact.

The mechanical/electrical reversing came first, the photo eyes came second.

Isn't it great to be old enough to know what it was like before the wheel???
Kinda like before all cars came with AC in the standard package, AC non existent then an option then no thought that it is there.

Originally Posted by Mark Reinmiller

Garry, Bottom line is that every door opener I have seen constructed since 1993 has photo eyes AND a reversing clutch that is adjustable for force. Forget the edge sensors. I have never seen any. If this is not clear, then look at any opener or instruction manual. The resistance clutch is present in addition to the photo eyes.

But, the UL and the Fed Regs do not use force as the criteria for reversal in doors without Edge Sensors. Though you may believe that you are adjusting the force exerted to reverse. The Regs deal only with time. I also was under the misconception that when I adjusted the operator I was working with force. I always set sensitivity to the highest point that I could and still have the door close. Which is why in another thread when Force or PSI was in discussion I contacted UL to see if they had any pressure criteria involved in testing protocol to meet requirements for installation. The answer was no, unless the door had an Edge Sensor. I have not tried to tracking down someone who actually was on the team that came up with their final protocal that has been implemented. Why they did not have force as a factor in the operator protocol for field testing would be interesting to know. Also I have not gone to the effort to see exactly how much force or PSI is being exerted when the maximum allowed (2 sec) contact takes place. A project to add to the list of thing to do one day.

Different doors have edge seals that vary in their stiffness and how much pressure it takes to compress them. Then there are the optional seals (bigger) that the standard shipped with the door that take even more pressure to compress. Yet it still is about time meeting the obstruction and not the amount of pressure to meet Regs requirements.

Sorry that you have not seen an edge sensor, they are out there which is why there is a criteria for them separate from the motor operator used.

Most of the edge sensors are on commercial installations.

As a side note.
Newer doors do not have the old adjustments. They are now a programing system to teach the operator to recognize travel limits. Also the sensitivity to meeting an obstruction is being taken over by the operator and taken away from the owner to maintain/test adjust.

The attached file is from a Liftmaster instruction manual with a 2007 copyright date. This page discusses how to adjust the FORCE activated reversing mechanism.

Also, Force and PSI are two different things. PSI has nothing to do with this topic. Liftmaster.JPG

Mark,
The installation instructions refer to the adjustment using the term "force mechanism adjustment" and yes the operator does apply a force to the door to move it up or down. Depending on the door, spring size and their adjustment, track and wheel lubrication the operator will be required to apply different amounts of force to move the door. The instructions also include testing the door half way down and up for reversal and stoppage. Which is always a fun discussion for the HIs and their personal testing methods. No argument that force is required to move the door up and down. If there was no force involved it would move by magic.

The instructions are telling the consumer/installer to adjustment the force to as light a possible (more sensitive) or in other words to use as little force as required to move the door. No where is there anything that says the amount of force (lbs) that is being applied just that they direct to have as little as required to operated the door satisfactorily.

The regs delineate between doors equipped with edge sensors and those not so equipped. Lift master is not addressing the edge sensor requirement because the operator they are supplying has no edge sensor.

There is also in the instructions the Federal required statement that the door must reverse on contact with a 2x4 block, though there is no description of what amount of force is required to trigger that reversal. Just that it reverse.

Originally Posted by Garry Sorrells

Mark,
The installation instructions refer to the adjustment using the term "force mechanism adjustment" and yes the operator does apply a force to the door to move it up or down. Depending on the door, spring size and their adjustment, track and wheel lubrication the operator will be required to apply different amounts of force to move the door. The instructions also include testing the door half way down and up for reversal and stoppage. Which is always a fun discussion for the HIs and their personal testing methods. No argument that force is required to move the door up and down. If there was no force involved it would move by magic.

The instructions are telling the consumer/installer to adjustment the force to as light a possible (more sensitive) or in other words to use as little force as required to move the door. No where is there anything that says the amount of force (lbs) that is being applied just that they direct to have as little as required to operated the door satisfactorily.

The regs delineate between doors equipped with edge sensors and those not so equipped. Lift master is not addressing the edge sensor requirement because the operator they are supplying has no edge sensor.

There is also in the instructions the Federal required statement that the door must reverse on contact with a 2x4 block, though there is no description of what amount of force is required to trigger that reversal. Just that it reverse.

Ok, after this I give up. A motor produces a constant about of torque, which is converted to a force. Adjusting the closing force does not change the torque, it changes the amount of force needed to reverse the door.

Perhaps the 2x4 test is not intended to test reversing force, but to see if the door reverses within 2 seconds?

Originally Posted by Mark Reinmiller

Ok, after this I give up. A motor produces a constant about of torque, which is converted to a force. Adjusting the closing force does not change the torque, it changes the amount of force needed to reverse the door.

Perhaps the 2x4 test is not intended to test reversing force, but to see if the door reverses within 2 seconds?

Sorry that you seem frustrated. But you are exactly right in your last statement on the 2x4 test.

The first part is correct also. There is force involved but the amount is subjective not quantitative. The manufacture refer to force in their installation instructions and how to increase and decrease the force required to open and close the door. The discussion of force stops when it comes to testing operation to meet Fed Requirements.

Some links that may be of interest:
DASMA
DASMA Door and Access Systems Manufacturers Association
Garage door openers manufactured after January 1, 1993, are required by federal law to have advanced safety features that comply with the latest UL (Underwriters Laboratories) 325 standards. Contact your manufacturer or installer for additional information.

• Test the reversing feature every month.

2. With the door fully open, place a 1-1/2" thick piece of wood (a 2" X 4" laid flat) on the floor in the center of the door

• Force Setting Test
  Test the force setting of your garage door opener by holding the bottom of the door as it closes. If the door does not reverse readily, the force setting may be excessive and need adjusting.

GENIE
Model : Powermax manual
http://www.geniecompany.com/data/pro...manual_eng.pdf

• Contact Reverse Test (page 9)

NOTE: The Limit and Force settings MUST BE COMPLETED before performing the Contact Reverse Test.

• Lay a 2” x 4” board _at under the center of the door opening.
• When the door contacts the board, it should stop and reverse direction within 2 seconds to the fully OPEN position

Model : Directlift manual
http://www.geniecompany.com/data/pro...60-install.pdf
Page 7

• The Open Force and Close Force Controls are to be set to the minimum force necessary to ensure the door smoothly opens and closes completely.

Page 8

• Limit Switch and Force Adjustments must be completed before checking the contact reverse function (Figure MA-3).

• B) Lay a 2” x 4” board flat in center of doorway.
• C) Close door using Wall Console.

Overhead Door MODELS Destiny1200, Destiny1500, Odyssey1000, & Odyssey1200
http://www.overheaddoor.com/garage-d...on-english.pdf
Page 4

• Safe-T-Reverse® Contact Reversing System

Automatically stops and reverses a closing door within two seconds of contact with an object.

• Automatic ForceGuard™ Control

Automatically sets the force required to fully open and close the door for maximum safety.
Page 9

• Lay a 2x4” board flat under the center of the door opening
• When the door contacts the board, it should stop and reverse direction within 2 seconds to the fully OPEN position.

Page 17

• Adjustment Guide - Force settings

Belt/Chain Drive – standard Drive 650 & Legacy 850

http://www.overheaddoor.com/garage-d...850-manual.pdf
When the door contacts the board, it should stop and reverse direction within 2 seconds to the fully open position. Red LED lights on the powerhead will begin to flash with the reversal of the do or. Remove the 2" x 4" board after a successful contact reversal test. The next cycle will clear the flashing red LEDs

Originally Posted by Allen Ingling

I appreciate all the good technical remarks by my many learned colleagues but Mark hits the "mark" in my opinion. I have tested many, many doors, long before the "eyes" came out and I would never stick a solid object in the path of a moving door. That could cause a lot of expensive unnecessary damage. I always do just as Mark does, I wait until the door is about thigh high and grasp the bottom with one hand. If I can't stop it, its a write up with strong warning not to ignore the condition, but to get a competent technician to fix it. I have never broken a door and I am pretty sure I have not caused any unnecessary alarm. If I can't stop the door then the force of the door would be enough to kill someone's cat or dog or severely

Allen, a word of advice from school of hard knocks. Wait until the top panel is nearly vertical before testing resistance. The operator arm horizontal pressure turns vertical in a heart beat. If the top panel bends under the vertical pressure the rollers pop out of there tracks and nothing can stop the chaos. Letting go of the bottom of the door no longer removes the "resistance" and if the downward pressure adjustment is set too high (9 out of 10 times) the jammed door crumples up like and old beer can. This is also another reason to test the resistance rather than relying on the 2X4 test only, as not all obstructions occur 3.5" from the floor.

Originally Posted by chad webster

..... while standing inside and extending my forearms with bent elbows at waist height to allow the door to come down on my forearms to meet resistance and hopefully return up again. EPIC FAILURE! ......
Am I at fault? .......

Originally Posted by Dom D'Agostino

Your testing methods aren't correct. That outstretched arm test has bested many inspectors and busted many doors.
..........

Originally Posted by Scott Patterson

......The method you used is not approved by any manufacturer or their garage door association for testing any door or opener........

Originally Posted by Lon Henderson

...... Some manufacturers use the "hand" test to set the obstruction sensor. But none of the manufacturers recommend grabbing the door around waist level...........For the future, revise your testing methods.

Returning to the OP and methods of testing a door operations.
Checking the force adjustment of the door is a valid test. It is not the first thing to do, though it is a valid test to perform prior to testing reversal at the floor using a 2x4 board.

For many years installers have been testing the force of the door as it closed. Testing the door force is a part of the normal operator installation and should be done prior to the floor obstruction reversal test, AKA the 2x4 test. The exception comes with the newest operators that the adjustment is more internalized in its actual adjustment. Though the should always reverse if it meets an obstruction above 1" from floor such as a car or a person standing the opening..

Here are sources for testing force reversal adjustment of the door operator by an Association and Manufactures.
DASMA http://www.dasma.com/safetygdmaint.asp
"Force Setting Test:
Test the force setting of your garage door opener by holding the bottom of the door as it closes. If the door does not reverse readily, the force setting may be excessive and need adjusting. See your owner’s manual for details on how to make the adjustment."

This test will demonstrate what may happen when the door meets an obstruction at the floor. It has been a typical installer's test as part of installing and adjusting the garage door operator for many years. Going back to the introduction of the reversal function on meeting resistance on operation of the door. It has a real purpose and like anything that you do common sense must be used.


Chamberlain
http://www.chamberlain.com/CatalogRe...s/114A3165.pdf
Page 21--- "1. Test the DOWN (close) force
• Grasp the door bottom when the door is about halfway through DOWN (close) travel. The door should reverse......"

Quatum : Wayne Dalton
http://www.gdosupport.com/interface/...tum_manual.pdf
Page 21 "CLOSING FORCE ADJUSTMENT to help determine that the closing door force is not excessive, grasp the door handle or bottom edge during downward travel. The opener should REVERSE to this force. NOTE: Do not stand under door during this test...."

Raynor
http://www.raynor.com/pdf/corporal_inst.pdf
1. Page 24 -- "Test the DOWN (close) force

Grasp the door bottom when the door is about halfway through DOWN (close) travel. The door should reverse. ..."
--------------------------------------------------------------------------------------------------
Picture from :: DASMA http://www.dasma.com/safetygdmaint.asp

Found some info for doors outside the USA dealing with FORCE exerted by door on closing for reversal and time to reverse, take a look at thread:

Garage Door Anti-Entrapment Force outside USA


http://www.inspectionnews.net/home_i...ad.php?t=43345

Great thread, thanks for the learned discussion. As most threads do, it made me go out looking for more information. I came across a safety campaign Liftmaster is promoting on their website, "Don't Chance it, Check it."

Observing that 1 in 15 garage doors may not be safe (I think that is a low number!) the safety campaign encourages homeowners to perform three tests;
1. Check the sides of the garage door for properly installed photo eyes (black sensors), mounted no higher than 6 inches off the floor. 2. Block the photo eye with an object over 6 inches tall, and press the Garage Door Opener's close button. The door should not close. 3. Lay an object that is at least 1.5 inches higher on the ground in the door's path, and press the close button. The door should reverse off this object.

The website includes a youTube video demonstrating the tests. Here's the link:

https://www.liftmaster.com/For-Homes/Garage-Safety

Thanks for sharing your experience and knowledge with the rest of us!

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Great thread, thanks for the learned discussion. As most threads do, it made me go out looking for more information. I came across a safety campaign Liftmaster is promoting on their website, "Don't Chance it, Check it." <br>
<br>
Observing that 1 in 15 garage doors may not be safe (I think that is a low number!) the safety campaign encourages homeowners to perform three tests; <br>
<font color="#313131"><span style="font-family: Helvetica Neue 55">1. Check the sides of the garage door for properly installed photo eyes (black sensors), mounted no higher than 6 inches off the floor. 2. </span></font><font color="#313131"><span style="font-family: Helvetica Neue 55">Block the photo eye with an object over 6 inches tall, and press the Garage Door Opener's close button. The door should not close. 3. </span></font><font color="#313131"><span style="font-family: Helvetica Neue 55">Lay an object that is at least 1.5 inches higher on the ground in the door's path, and press the close button. The door should reverse off this object.</span></font><font color="#313131"><span style="font-family: Helvetica Neue 55"><br>
</span></font><br>
The website includes a youTube video demonstrating the tests. Here's the link:<br>
<br>
<a href="https://www.liftmaster.com/For-Homes/Garage-Safety" target="_blank" rel="nofollow">https://www.liftmaster.com/For-Homes/Garage-Safety</a><br>
<br>
Thanks for sharing your experience and knowledge with the rest of us!

- - - Updated - - -

Great thread, thanks for the learned discussion. As most threads do, it made me go out looking for more information. I came across a safety campaign Liftmaster is promoting on their website, "Don't Chance it, Check it." &lt;br&gt;<br>
&lt;br&gt;<br>
Observing that 1 in 15 garage doors may not be safe (I think that is a low number!) the safety campaign encourages homeowners to perform three tests; &lt;br&gt;<br>
&lt;font color="#313131"&gt;&lt;span style="font-family: Helvetica Neue 55"&gt;1. Check the sides of the garage door for properly installed photo eyes (black sensors), mounted no higher than 6 inches off the floor. 2. &lt;/span&gt;&lt;/font&gt;&lt;font color="#313131"&gt;&lt;span style="font-family: Helvetica Neue 55"&gt;Block the photo eye with an object over 6 inches tall, and press the Garage Door Opener's close button. The door should not close. 3. &lt;/span&gt;&lt;/font&gt;&lt;font color="#313131"&gt;&lt;span style="font-family: Helvetica Neue 55"&gt;Lay an object that is at least 1.5 inches higher on the ground in the door's path, and press the close button. The door should reverse off this object.&lt;/span&gt;&lt;/font&gt;&lt;font color="#313131"&gt;&lt;span style="font-family: Helvetica Neue 55"&gt;&lt;br&gt;<br>
&lt;/span&gt;&lt;/font&gt;&lt;br&gt;<br>
The website includes a youTube video demonstrating the tests. Here's the link:&lt;br&gt;<br>
&lt;br&gt;<br>
&lt;a href="https://www.liftmaster.com/For-Homes/Garage-Safety" target="_blank" rel="nofollow"&gt;https://www.liftmaster.com/For-Homes/Garage-Safety&lt;/a&gt;&lt;br&gt;<br>
&lt;br&gt;<br>
Thanks for sharing your experience and knowledge with the rest of us!

- - - Updated - - -

Great thread, thanks for the learned discussion. As most threads do, it made me go out looking for more information. I came across a safety campaign Liftmaster is promoting on their website, "Don't Chance it, Check it." &lt;br&gt;<br>
&lt;br&gt;<br>
Observing that 1 in 15 garage doors may not be safe (I think that is a low number!) the safety campaign encourages homeowners to perform three tests; &lt;br&gt;<br>
&lt;font color="#313131"&gt;&lt;span style="font-family: Helvetica Neue 55"&gt;1. Check the sides of the garage door for properly installed photo eyes (black sensors), mounted no higher than 6 inches off the floor. 2. &lt;/span&gt;&lt;/font&gt;&lt;font color="#313131"&gt;&lt;span style="font-family: Helvetica Neue 55"&gt;Block the photo eye with an object over 6 inches tall, and press the Garage Door Opener's close button. The door should not close. 3. &lt;/span&gt;&lt;/font&gt;&lt;font color="#313131"&gt;&lt;span style="font-family: Helvetica Neue 55"&gt;Lay an object that is at least 1.5 inches higher on the ground in the door's path, and press the close button. The door should reverse off this object.&lt;/span&gt;&lt;/font&gt;&lt;font color="#313131"&gt;&lt;span style="font-family: Helvetica Neue 55"&gt;&lt;br&gt;<br>
&lt;/span&gt;&lt;/font&gt;&lt;br&gt;<br>
The website includes a youTube video demonstrating the tests. Here's the link:&lt;br&gt;<br>
&lt;br&gt;<br>
&lt;a href="https://www.liftmaster.com/For-Homes/Garage-Safety" target="_blank" rel="nofollow"&gt;https://www.liftmaster.com/For-Homes/Garage-Safety&lt;/a&gt;&lt;br&gt;<br>
&lt;br&gt;<br>
Thanks for sharing your experience and knowledge with the rest of us!

- - - Updated - - -

Great thread, thanks for the learned discussion. As most threads do, it made me go out looking for more information. I came across a safety campaign Liftmaster is promoting on their website, "Don't Chance it, Check it." &lt;br&gt;<br>
&lt;br&gt;<br>
Observing that 1 in 15 garage doors may not be safe (I think that is a low number!) the safety campaign encourages homeowners to perform three tests; &lt;br&gt;<br>
&lt;font color="#313131"&gt;&lt;span style="font-family: Helvetica Neue 55"&gt;1. Check the sides of the garage door for properly installed photo eyes (black sensors), mounted no higher than 6 inches off the floor. 2. &lt;/span&gt;&lt;/font&gt;&lt;font color="#313131"&gt;&lt;span style="font-family: Helvetica Neue 55"&gt;Block the photo eye with an object over 6 inches tall, and press the Garage Door Opener's close button. The door should not close. 3. &lt;/span&gt;&lt;/font&gt;&lt;font color="#313131"&gt;&lt;span style="font-family: Helvetica Neue 55"&gt;Lay an object that is at least 1.5 inches higher on the ground in the door's path, and press the close button. The door should reverse off this object.&lt;/span&gt;&lt;/font&gt;&lt;font color="#313131"&gt;&lt;span style="font-family: Helvetica Neue 55"&gt;&lt;br&gt;<br>
&lt;/span&gt;&lt;/font&gt;&lt;br&gt;<br>
The website includes a youTube video demonstrating the tests. Here's the link:&lt;br&gt;<br>
&lt;br&gt;<br>
&lt;a href="https://www.liftmaster.com/For-Homes/Garage-Safety" target="_blank" rel="nofollow"&gt;https://www.liftmaster.com/For-Homes/Garage-Safety&lt;/a&gt;&lt;br&gt;<br>
&lt;br&gt;<br>
Thanks for sharing your experience and knowledge with the rest of us!

Looks like the correct way to test the doors is based on manufacturer info and that there is no set across-the-board testing method.

Originally Posted by Garry Sorrells

Found some info for doors outside the USA dealing with FORCE exerted by door on closing for reversal and time to reverse, take a look at thread:

Garage Door Anti-Entrapment Force outside USA


http://www.inspectionnews.net/home_i...ad.php?t=43345

Good job Garry. Fortunately you introduced my favorite topic, force vs. pressure vs. torque vs. whatever. We beat this to death on cable railings and here it is again. The simple way to measure door reversal force is with the same scale I use on the railings. I've included a photo of how to do it if you want to. As with the railings, I like to see over 50 lbs. force on a door reversal. I have not seen any go to the force Garry quotes, usually they are under 75 lbs which I can easily stop with one hand. The picture shows the height at which I always test, about thigh high (on me), at this point the top panel is still horizontal and having tested hundreds of these I have not broken one yet (I'm only 78, I may test a few more yet).

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Originally Posted by Garry Sorrells

Found some info for doors outside the USA dealing with FORCE exerted by door on closing for reversal and time to reverse, take a look at thread:

Garage Door Anti-Entrapment Force outside USA


http://www.inspectionnews.net/home_i...ad.php?t=43345

Good job Garry. Fortunately you introduced my favorite topic, force vs. pressure vs. torque vs. whatever. We beat this to death on cable railings and here it is again. The simple way to measure door reversal force is with the same scale I use on the railings. I've included a photo of how to do it if you want to. As with the railings, I like to see over 50 lbs. force on a door reversal. I have not seen any go to the force Garry quotes, usually they are under 75 lbs which I can easily stop with one hand. The picture shows the height at which I always test, about thigh high (on me), at this point the top panel is still horizontal and having tested hundreds of these I have not broken one yet (I'm only 78, I may test a few more yet).

I may be retired but this thread has been beat to death for ages and just have to repeat the fact that garage door operator standards are prescribed by Federal Regulations. Manufacturers usually reword the Federal requirements to provide pertinent details and omit the extra verbiage. Although a closing "pressure" requirement would seem to be more applicable to some, the regulations are for non-entrapment not total safety. There are no pressure standards so measuring the force means what? How would you determine how much pressure is too much?

I cut a piece of wood (cherry) 1-1/2" square, about 12" long, and carried it in my tool bag. I also put lines around the block to indicate the mounting height of the secondary IR beam. The 6" position was in red, and a black line at each inch above the red line. That way I could easily illustrate in a picture if the beam was too high and by how much by standing the block on end at the eye. I referred to the center of the beam lenses.

From the OP description, I would think this was a handyman or homeowner installation. It seemed odd to me that the manufacturers' instructions I found did not include the reversal test in the installation section but in the maintenance section.

The following is the Federal document. Look it up. You don't need to look up each individual manufacturer.

[Code of Federal Regulations]
[Title 16, Volume 2]
[Revised as of January 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 16CFR1211.15]

[Page 337-338]
TITLE 16--COMMERCIAL PRACTICES
CHAPTER II--CONSUMER PRODUCT SAFETY COMMISSION
PART 1211--SAFETY STANDARD FOR AUTOMATIC RESIDENTIAL GARAGE DOOR OPERATORS-

Originally Posted by Stuart Brooks

I cut a piece of wood (cherry) 1-1/2" square, about 12" long, and carried it in my tool bag. I also put lines around the block to indicate the mounting height of the secondary IR beam. The 6" position was in red, and a black line at each inch above the red line. That way I could easily illustrate in a picture if the beam was too high and by how much by standing the block on end at the eye. I referred to the center of the beam lenses.

Did you also have a line at the 4" position?

Originally Posted by Jerry Peck

Did you also have a line at the 4" position?

No. I never had a too low installation to illustrate

Originally Posted by Stuart Brooks

No. I never had a too low installation to illustrate

I've seen them setting on the floor, which makes them too low.

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Originally Posted by Stuart Brooks

.......There are no pressure standards so measuring the force means what? How would you determine how much pressure is too much?

.......... It seemed odd to me that the manufacturers' instructions I found did not include the reversal test in the installation section but in the maintenance section.

The following is the Federal document. Look it up. You don't need to look up each individual manufacturer.

.....

No pressure standards for overhead door operators means just that in the US. Pressure to trigger reversal is not something that Underwriters Labs focused on and thus was not an issue in the Fed Regs. It is time on contact. Thus it could be any amount of pressure exerted so long as it reversed within 2 sec. I have not tracked down anyone that actually participated in U.Ls. testing development and subsequent protocols on operation criteria. Pretty sure it all derived from the fact that they wanted a non instrumented way to demonstrate the door operating within a specification. So it is a 1" block that turned into accepting a 2x4 for practicality/convenience in home owner testing.

Manufacture instructions mirror the Fed Regs and yet the manufacture's instructions have changed over the years. Today you find that testing reversal above the floor in many instructions and also DASMA instructions on testing.

Most often our discussion turns to what the particular product manufacture states in their instructions as to determine installation and testing criteria. Looking at various manufacture instructions can demonstrate what the accepted norm may be. Decades back testing the pressure needed to cause the door to reverse was a norm for installers, even though not specified in the Fed Regs or manufacture instructions. It was just what the installer would do to protect the door from being damaged during installation adjustments of the operator.


The regs say that he door must reverse on meeting an obstruction at any point of its operating cycle which is a backhanded way to say that you should test the door at various positions of operation to assure that the Regs are being met for reversal.

This thread is just part of the never ending story for the topic. Yet you fired it back up after 6 months of dormancy.

Originally Posted by Jerry Peck

I've seen them setting on the floor, which makes them too low.

Is there a federal guideline saying that is too low?

Originally Posted by Lon Henderson

Is there a federal guideline saying that is too low?

Almost all of the installation instructions I've seen require them to be installed between 4" and 6" above the floor.

I'd have to check the federal standards to see if they have that requirement too ... but if the installation instructions have it - it is a requirement.

Manufacture instructions for placement derive from:

e-CFR data is current as of November 18, 2015
eCFR

§1211.11 Requirements for photoelectric sensors.
§1211.11 Requirements for photoelectric sensors.

(2) The obstruction noted in paragraph (a)(1) of this section shall consist of a white vertical surface 6 inches (152 mm) high by 12 inches (305 mm) long. The obstruction is to be centered under the door perpendicular to the plane of the door when in the closed position. See figure 3.

Originally Posted by Lon Henderson

Is there a federal guideline saying that is too low?

Originally Posted by Jerry Peck

Almost all of the installation instructions I've seen require them to be installed between 4" and 6" above the floor.

I'd have to check the federal standards to see if they have that requirement too ... but if the installation instructions have it - it is a requirement.

I went through CFR 16-1211 and did not find a requirement for 4" high ... or 6" high.

And there is an additional test with a 4" high object, not just a '2x4'.

Read through the sections here: eCFR

I will add, before someone points it out, that I do know where that 6" 'requirement ' came from and why it is thought of as a 'requirement'. Most things in CFR 16-1211 are spelled out to a 'T' with the 'i's' dotted and the 't's' crossed.

Originally Posted by Jerry Peck

I went through CFR 16-1211 and did not find a requirement for 4" high ... or 6" high.

I didn't see it either when I read that a year or so ago. I'm not going to go hunting through installation instructions, but I'm pretty sure that I've read the 6" maximum in several of them, but I don't remember a minimum.

Originally Posted by Lon Henderson

I'm not going to go hunting through installation instructions, ..

I did when I was doing AHJ inspections - so I would know how it was supposed to be installed.

but I'm pretty sure that I've read the 6" maximum in several of them, but I don't remember a minimum.

The second one I looked at online: http://www.overheaddoor.com/garage-d...on-english.pdf - Step 2 - the mounting bracket for the photo cell ... maximum 6" high, min 5" high ... which would be the top of the photo cell, that would put the photo cell at about 4" min to 5-1/2" high max based on the apparent size of the bracket.

Originally Posted by Keith Rogers

"Don't Chance it, Check it."

Observing that 1 in 15 garage doors may not be safe (I think that is a low number!) the safety campaign encourages homeowners to perform three tests;
1. Check the sides of the garage door for properly installed photo eyes (black sensors), mounted no higher than 6 inches off the floor. 2. Block the photo eye with an object over 6 inches tall, and press the Garage Door Opener's close button. The door should not close. 3. Lay an object that is at least 1.5 inches higher on the ground in the door's path, and press the close button. The door should reverse off this object.

The website includes a youTube video demonstrating the tests. Here's the link:

https://www.liftmaster.com/For-Homes/Garage-Safety

Thanks for sharing your experience and knowledge with the rest of us!


Thanks for sharing your experience and knowledge with the rest of us!

I concur. Happy to be here.

Been waiting for someone to present the explanation/rational behind why some manufactures instruct position of sensor above 4 inches from floor and no higher than 6 inches. But I will give it a try. I have attempted to provide the most relevant sections as they relate to each other for reference and as they are mentioned. So you can follow the exact wording.


There is a requirement that the door reverse if it meets an obstruction or movement is impeded, a change in the constant pressure, and prior to 1 inch from the floor such as a car hood or a person standing in the opening. .See: “§1211.6 (b)(1)(ii) Reverse direction and open the door to the upmost position when constant pressure on a control is removed prior to operator reaching its lower limit, and”

We have discussed the method of using you hand to test the §1211.6 (b)(1)(ii) requirement which some manufactures like Chamberlain now list in their installation instructions as well as DASMA (The page cannot be found). This test yields the same effective result to fulfill the requirement as described in §1211.7 (a)(1). By following the specifications of §1211.7 (b)(3) the same result is obtained by the tester without having to personally touch the door. It is achieved using a solid block. Personally I still like to use my hands for many reasons.

Now this is where the 4 inch to 6 inch height gets introduced for the photo sensors. The sensors have to be less than 6 inches so that a child or adult arm /leg trigger the sensor. The height of 4 inches assures that the door obstruction is higher than the 1” requirement. They could have made it 2 inches, but they didn’t. So the sensors to be installed and working and at the same fulfill the requirement of §1211.6 (b)(1)(ii) and §1211.7( a)(1) the sensors have to be greater than 4 inches from floor else the block would trigger the door not to move.




{{{ I have highlighted- BOLD }}} Reference as mentioned sequentially: eCFR

§1211.6 (b)(1)(ii) Reverse direction and open the door to the upmost position when constant pressure on a control is removed prior to operator reaching its lower limit, and

§1211.7 ( a)(1) Other than for the first 1 foot (305mm) of door travel from the full upmost position both with and without any external entrapment protection device functional, the operator of a downward moving residential garage door shall initiate reversal of the door within 2 seconds of contact with the obstruction as specified in paragraph (b) of this section. After reversing the door, the operator shall return the door to, and stop at, the full upmost position. Compliance shall be determined in accordance with paragraphs (b) through (i) of this section.

§1211.10(a) (3) The door operator is not required to return the door to, and stop the door at, the full upmost position when a control is actuated to stop the door during the upward travel—but the door can not be moved downward until the operator reverses the door a minimum of 2 inches (50.8 mm).

§1211.7(b) (3) To test operators for compliance with requirements in paragraphs (a)(3), (f)(3), and (g)(3) of this section, §1211.10(a)(6)(iii), and §1211.13(c), a solid rectangular object measuring 4 inches (102 mm) high by 6 inches (152 mm) wide by a minimum of 6 inches (152 mm)long is to be placed on the floor of the test installation to provide a 4-inch (102 mm) high obstruction when operated from a partially open position.

§1211.7 (f)(3) The door operator is not required to return the door to, and stop the door at, the full upmost position when a control is actuated to stop the door during the upward travel—but the door can not be moved downward until the operator reverses the door a minimum of 2 inches (50.8 mm).


§1211.7 (g)(3) The door operator is not required to return the door to, and stop the door at, the full upmost position when a control is actuated to stop the door during the upward travel—but the door can not be moved downward until the operator reverses the door a minimum of 2 inches (50.8 mm). When the door is stopped manually during its descent, the 30 seconds shall be measured from the resumption of the close cycle.


§1211.10 (a)(6)(iii) The door operator is not required to return the door to, and stop the door at, the full upmost position when a control is actuated to stop the door during the upward travel—but the door can not be moved downward until the operator has reversed the door a minimum of 2 inches (50.8 mm).

§1211.13 (c) Obstruction test. For a door traveling in the downward direction, when an inherent secondary entrapment protection device senses an obstruction and initiates a reversal, a control activation shall not move the door downward until the operator reverses the door a minimum of 2 inches (50.8 mm). The test is to be performed as described in §1211.7(b)(3).



§1211.7 (b)(3). To test operators for compliance with requirements in paragraphs (a)(3), (f)(3), and (g)(3) of this section, §1211.10(a)(6)(iii), and §1211.13(c), a solid rectangular object measuring 4 inches (102 mm) high by 6 inches (152 mm) wide by a minimum of 6 inches (152 mm)long is to be placed on the floor of the test installation to provide a 4-inch (102 mm) high obstruction when operated from a partially open position.

Garry,

I see you found the 4 inches I referred to - but I don't see that you've found the 6 inches height I referred to.

Here is where the 6 inches height comes from:
- eCFR

§1211.11 Requirements for photoelectric sensors.
- (a) Normal operation test. (1) When installed as described in §1211.10(a) (1)-(4), a photoelectric sensor shall sense an obstruction as described in paragraph (a)(2) of this section that is to be placed on the floor at three points over the width of the door opening, at distances of 1 foot (305 mm) from each end and the midpoint.
- - (2) The obstruction noted in paragraph (a)(1) of this section shall consist of a white vertical surface 6 inches (152 mm) high by 12 inches (305 mm) long. The obstruction is to be centered under the door perpendicular to the plane of the door when in the closed position. See figure 3.

See figure 3 in the above link.

If the photo cell is above 6 inches high, the photo cell will not detect the 6 inch test obstruction. That means the maximum height permitted for the photo cell is 6 inches above the floor.

Many contractors (at least in Florida) build in a 3/4" recess for the garage door to close to so that the garage door closes below the garage floor level to help prevent wind blown rain and water penetration into the garage.

IF ... if that recess extends 6 inches in from the center of the door, one could measure the 6 inch height as being from above that recess (I am not recommending such, but IF the recess is that wide, it would meet the CFR 16-1211.11 requirements).

Most recesses I have seen are maybe a minimum of 5-1/2 inches wide (1x6 width to clear a 2x4 or 2x6 frame wall) to 9-1/4 inches wide (1x10 width to clear an 8 inch wide block wall) with the door being near the inside edge of the recess - which means measuring from the garage floor.

And, yes, I think some manufacturer's include 4 inches, or even 5 inches, to be above that 4" high obstruction, but ... that is not listed for the photo cell test, so some don't include any minimum height, not even for the 1" closing space at the bottom of the travel.

At least that is my thinking of how the 4 inch minimum and 6 inch maximum heights made their way into the manufacturer's installation instructions. Garry was on the right track, just hadn't pulled all the way into the station yet.

Originally Posted by Jerry Peck

Garry,

I see you found the 4 inches I referred to - but I don't see that you've found the 6 inches height I referred to.

Originally Posted by Garry Sorrells

Manufacture instructions for placement derive from:

e-CFR data is current as of November 18, 2015
eCFR

§1211.11 Requirements for photoelectric sensors.
§1211.11 Requirements for photoelectric sensors.

(2) The obstruction noted in paragraph (a)(1) of this section shall consist of a white vertical surface 6 inches (152 mm) high by 12 inches (305 mm) long. The obstruction is to be centered under the door perpendicular to the plane of the door when in the closed position. See figure 3.

From Post #57. is the 6" see Pict I included. which is Fig 3. (top figure)

You are trying to lump the 4" and 6" together. The 4" is for an obstruction that the door actually hits and the 6" is if there is something laying on the floor for the photo eye to see.