Thread: Garage door retractor

Fuel for the fire for discussion. Sorry that it turned out long.

Vern,
I thought you were were writing your interpenetration of the NC Law. The NC Law like most all SOP is reliant on interpretation. Usually falling back on manufactures specifications and manuals. Different manufactures will have different requirements, even within the company for different models and different years.

So for clarification of others that may review this thread.
NC SOP does require but does not specify the actual testing methodology that you stated as required, ""Grasping the bottom of the door is a listed test and is the test required by my licensure board. ...""

NC SOP .1107 EXTERIOR
(4) Report whether or not any garage door operator will automatically reverse or stop when meeting reasonable resistance during closing;

Without actually stating it NC leaves it up to the HI to determine testing methods. What the HI bases the test method is a matter for the HI to justify if/when challenged. The HI can go to manufacture or other resources to find testing methods and then use those methods as the basis for developing the HI's method of testing across various manufactures and installations.


The real issue is that when presented with an door/gate opener they are of varying in age and manufactures. Again for myself though time consuming, I want to test without damaging the system so I test in increments ending in testing with a 2x on the floor. Stopping at the point where I determine a testing failure.

The original question by Marc,

“Is there a minimum / max pressure for the physical retracting mechanism, not the lower eye.”, I found interesting, having never heard or seen an actual PSI #. Which now has me trying to obtain an answer form different manufactures. Better late than never.


I have received one reply which I found disappointing but in some respects not surprising. I specified a specific model hoping to make it easier to obtain a clear response. Here is the slightly edited email and reply

Email sent:
Chamberlain Product Support
Model WD962KEV
"...I would like too know what the maximum acceptable amount of pressure that is exerted when the door meets an object as it closes. Specifically the pounds per square inch (PSI) to trigger the safety reverse sensing technology function...."

Reply:
"Chamberlain Support" <technical.support@chamberlain.com
"...The travel and force is programmed to the logic board. Using the 2X4 you can check the force reversal. the unit will hit the board and open back up.

Chamberlain does not provide this information, our corporate office considers this information to be proprietary. ..."
Sincerely,
Maryann
Chamberlain Product Support

In my email I did not mention any potential issues of damage, only a request for a SPI. I will be following up on this with Chamberlain and other manufactures to attempt to obtain something specific on the PSI trigger question.

The guys are right, Peck is mostly wrong in his insistance that the first and only test should be a 2x4 test.

The 2x4 test is the last step in inspecting a garage door manufactured on/after 1991.First of all the 2x4 test should NEVER be employed before testing the BALANCING of the garage door after first visually inspecting the door, handles, locks, tracks (and obstructions placed therein), opening system, spring restraint system (cables or other) etc.

Visual inspection.

Next inspect for signs of insufficient or incorrect lubrication (noises, skips, drips, foreign matter contaminating, etc.).

Check the release feature(s) including the quick release feature.

Next check the balancing system. (requiring manual operation of the door) Further verify balancing system released and stop door when opening at mid way about 3-4' off the floor-ish and assure it holds open (procedure described on DASMA.org link provided below).

Next if manufactured on/after 1993 determine which of several additional stop and/or stop/reverse safety features required are present and test their operation. (all of which are hands off and out of the way of a failing falling door.

Next the hand force test (from outside not inside the garage under the door!)

Then and only then check via the 2x4 test which is required in all such systems to protect against entrapment between something and THE FLOOR manufactured on/after 1991.

If failing any of the prerequisite tests/inspections do not proceed and recommend further evaluation, adjustment, repair or replacement by a qualified professional. Most springs and safety cables/restraints should ONLY be evaluated for alteration, adjustment, repair or replacement by a qualified professional.

The instructions/manual is supposed to be present. Always refer to manufacturer's instructions, safety, warnings, and maintenance. The manufacturers will always supply information regarding monthly inspections and testing if manufactured on/after 1993.

I strongly recommend to all H.I.s, H.O.s, etc. to the following link (and perhaps direct property owners, clients, etc. to) for the SAFE PROCEDURE STEPS (with additonal information regarding same) here: DASMA Door and Access Systems Manufacturers Association It is important information is provided by the U.S. Consumer Product Safety Commission, the National Safety Council, and the Industry Coalition for Automatic Garage Door Opener Safety.

I used to have a pdf file of a brochure with similar info from the NSC but cannot locate it at the moment.

As well, numerous entrapment issues can occur above the floor - against a surface or obstruction other than the floor causing injuries and deaths see the Consumer Product Safety Commission (CPSC) web page below and UL.com (UL Standard technical panel STP 325, & UL Standard 325). Additional Information (Page with many useful links at CPSC here): Voluntary Standards - Garage Door Operators/Gate Operators Additionally I'm uploading CPSC Publication 523 (pdf file).

Garry, you might try writing to UL for further information concerning ANSI/UL 325 Standard for Safety for Door, Drapery, Gate, Louver, and Window Operators and Systems, by contacting Joe Musso at Joseph.R.Musso@us.ul.com for your questions regarding force etc.

The mandatory standards can be found at US 16 CFR part 1211, Commercial Practices

WARNING! If the force is set too high or the balancing is off a catastrophic failure can occur during the 2x4 test. The 2x4 test should not be employed if a door fails the Force Setting Test or the balancing test (or the foregoing inspections and examinations). A catastrophic failure can result in injury, death, or property damage.

Originally Posted by Garry Sorrells

Fuel for the fire for discussion. Sorry that it turned out long.

Vern,
I thought you were were writing your interpenetration of the NC Law. The NC Law like most all SOP is reliant on interpretation. Usually falling back on manufactures specifications and manuals. Different manufactures will have different requirements, even within the company for different models and different years.

So for clarification of others that may review this thread.
NC SOP does require but does not specify the actual testing methodology that you stated as required, ""Grasping the bottom of the door is a listed test and is the test required by my licensure board. ...""

NC SOP .1107 EXTERIOR
(4) Report whether or not any garage door operator will automatically reverse or stop when meeting reasonable resistance during closing;

Without actually stating it NC leaves it up to the HI to determine testing methods. What the HI bases the test method is a matter for the HI to justify if/when challenged. The HI can go to manufacture or other resources to find testing methods and then use those methods as the basis for developing the HI's method of testing across various manufactures and installations.


The real issue is that when presented with an door/gate opener they are of varying in age and manufactures. Again for myself though time consuming, I want to test without damaging the system so I test in increments ending in testing with a 2x on the floor. Stopping at the point where I determine a testing failure.

I agree with all you have said. My contention is; a 2x4 is infinite resistance, for all practical purpose, leaving the amount of force (resistance) required to reverse the door as an unknown.

As you have been using the 2x4, how many have failed as a final test?

Sectional Garage Door and Electric Operator Checklist for Home Inspectors and Consumers: http://www.dasma.com/PDF/Publication...ial/TDS167.pdf

Note #10, page 3 (Contact Reversal Test):

In some rare cases, this test has damaged the door system when the Operators Force-Setting has been improperly set or when the Operator Reinforcement Bracket is not secrely or appropriately attached to the top section. If you have any concerns that this test may cause damage, a trained door systems technician should check the entire system and conduct the test.

Also attached.

See also the following, regarding manual inspection and operation of Garage door prior to testing electric operator.

http://www.dasma.com/PDF/Publication...ial/TDS174.pdf

additionally attached.


DASMA Door and Access Systems Manufacturers Association

has much more.

Let me get this straight ... you said not to do the 2x4 test I talk about ... then you linked to a document which shows that as the correct test method???

Originally Posted by Doctor Haus

The guys are right, Peck is mostly wrong in his insistance that the first and only test should be a 2x4 test.
.
I strongly recommend to all H.I.s, H.O.s, etc. to the following link (and perhaps direct property owners, clients, etc. to) for the SAFE PROCEDURE STEPS (with additonal information regarding same) here: DASMA Door and Access Systems Manufacturers Association It is important information is provided by the U.S. Consumer Product Safety Commission, the National Safety Council, and the Industry Coalition for Automatic Garage Door Opener Safety.

Huh????

Either you are for the 2x4 test or you are not, and apparently you are for the 2x4 test as you referred and linked to that document.

Originally Posted by Doctor Haus

The guys are right, Peck is mostly wrong in his insistance that the first and only test should be a 2x4 test.
...

Next the hand force test (from outside not inside the garage under the door!)

I strongly recommend to all H.I.s, H.O.s, etc. to the following link (and perhaps direct property owners, clients, etc. to) for the SAFE PROCEDURE STEPS (with additonal information regarding same) here: DASMA Door and Access Systems Manufacturers Association .

Doc
First of all Jerry did not say it is the first and only test

Next did you even read the link you provided
I think not
http://www.dasma.com/PDF/Publication...ial/TDS167.pdf
Nothing in the DASMA 10 step inspection procedure about using your hand to hold back the door.

Hello Fellas,

For those who like testing the door by stopping it with their hands (presumably at approx. waist height), I am curious how you think an ergonomic professional, back doctor, P.I. lawyer and OSHA would respond if you asked them following:

Do you think it is a good idea to stand under a large downward moving object than can weigh as much as 400 hundred pounds, that is on a set of tracks and motor driven with a force behind it that we don’t know, and attempt to stop this object from its intended downward motion to see if a safety device works to make this object stop and go back up. And, use a body part to conduct this test?

Just curious what other professionals in other industries might say.

I have never read an instruction manual that says to use a body part to stop a mechanical moving object.

I have no intention of changing anyone’s mind. I sincerely wish for all to be safe and do what they believe is best for themselves and their clients.

Be well,

Corey

In this forum I am frequently amazed at how many adults who call themselves professionals claim to have no common sense or good judgment.

... not to mention the constant pissing contests!

Not a pissing match at all, and I certainly think every person here has plenty of common sense.

Home inspectors, as a group, are accustomed to having their opinions challenged and criticized, by trades people, sellers, and agents.
Almost everyone here has heard a trades person or agent say, “ He doesn’t know what he’s talking about”. The HI cannot allow the criticism to alter his opinion.
However, the HI cannot become so entrenched that he is unwilling to examine himself and his methods.
It does not surprise me that some are reluctant to accept using a 2x4. Years of hearing inspector folklore and rumors of disaster have them understandable skeptical.
Only by trust in the words of a few and accepting the validity of written instructions, are they willing to do what they have feared.

Understanding takes trust
Trust takes change
Change takes time

As I said before, it took courage for Lon and Vern.

Originally Posted by Rick Cantrell

Doc
First of all Jerry did not say it is the first and only test

Next did you even read the link you provided
I think not
http://www.dasma.com/PDF/Publication...ial/TDS167.pdf
Nothing in the DASMA 10 step inspection procedure about using your hand to hold back the door.

Wasn't the link I provided.

You're not alone, all of the last five posters have evidenced that they do not read.

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.

Was from the link I provided.

Testing a GDO is a progressive process and when properly done, is halted, whenever a step in the process indicates a problem. Proceeding to a 2x4 test is foolhardy if the GD or the GDO has already been found to have a problem condition, adjustment, etc. and "failed under testing" is not a valid response if having done so.

The .pdf you refer to also makes mention of the force setting and manufacturers instructions.

You do not stand in the garage nor under the Garage Door when you perform a force setting test, just as you do not stand in the garage nor under the garage door when you perform a balancing test.

I did not say folks had no common sense, only that they claim not to have. Many of the HIs appear to use "approved", "listed", "required" and other buzz words to escape ownership of their decisions, policies and practices. For instance, if one can say, "It's not listed for that" then one has an excuse not to render an opinion whether it will work or not.

Sorry Doc
I did not mean to misquote you.
I had several pages open at the same time all from that site.

Marc: At one time 35 lbs pressure was recommended. DONT use a 2x4 I did this once and the door fell apart, I had to pay big for this!!!! I do know they say to do this.... Trust me don"t

Originally Posted by Corey Friedman

Hello Fellas,

For those who like testing the door by stopping it with their hands (presumably at approx. waist height), I am curious how you think an ergonomic professional, back doctor, P.I. lawyer and OSHA would respond if you asked them following:

Do you think it is a good idea to stand under a large downward moving object than can weigh as much as 400 hundred pounds, that is on a set of tracks and motor driven with a force behind it that we don’t know, and attempt to stop this object from its intended downward motion to see if a safety device works to make this object stop and go back up. And, use a body part to conduct this test?

Just curious what other professionals in other industries might say.

I have never read an instruction manual that says to use a body part to stop a mechanical moving object.

I have no intention of changing anyone’s mind. I sincerely wish for all to be safe and do what they believe is best for themselves and their clients.

Be well,

Corey

A block of wood is solid while a small child is not.
How many people have been injured after my better hand test (zero)
How many kids get crushed for being less solid than a block of wood or wider than one inch we may never know.

If you guys are happy filling insurance forms for damaged doors then it is up to you.

Please explain how a "solid" block of wood determines the exact amount of pressure sensitivity.

Originally Posted by Corey Friedman

Hello Fellas,


I have never read an instruction manual that says to use a body part to stop a mechanical moving object.



Corey

Okay, Elevator doors are tested and operate on the practise that if something, body part perhaps, closes the safety switch the door opens. The other one I can think of is in one of the battle tanks, the bomb door has same type of mechanism. Body part gets in front it opens back up to prevent crushing.
My garage door was tested twice last year, both times by my wife, on her RAV4. And both times the door raised as expected, if it hadnt she woulda drove out with it on the roof. Spare tire cover took the hit both times. They cost about $800...saved the garage door though

Originally Posted by Stephen G

Okay, Elevator doors are tested and operate on the practise that if something, body part perhaps, closes the safety switch the door opens. The other one I can think of is in one of the battle tanks, the bomb door has same type of mechanism. Body part gets in front it opens back up to prevent crushing.
My garage door was tested twice last year, both times by my wife, on her RAV4. And both times the door raised as expected, if it hadnt she woulda drove out with it on the roof. Spare tire cover took the hit both times. They cost about $800...saved the garage door though

Stephen,

Elevator doors are specifically designed for that function.

Battle tanks and bomb doors... really? Kinda specialized including specialized training.

Corey

The reason the manufacturers recommend block of wood is two fold.
Damage the door testing and they sell more product.
Second reason is the same as for why they have a warning your coffee is hot on the cup.
LIABILITY.

If it is a 12-14 Lb retract setting then my hand method is a much better judge than a solid block of wood damaging a door and also does what the block can not which is make sure it retracts on light pressure not to mention very few kids are one inch tall.

Guys will use one or the other method but nobody can tell me my method is wrong .Too many years in this to not think for myself.

Me too, I am sticking with my hand test method. Only have had one cheap aluminum door buckle where the track arm was mounted onto the door. I was able to straighten it out by hand.

How does one test swing up doors that have a power lift?

Ray, you would need to wedge the 6 foot long 2x4 at the edge going back to the door frame and if it pops off the springs and drops the car door you simply write it up as failed under testing.

Talk to what you know, In my past life I was a heavy armoured mechanic and frequent elevator door tester, just like you.
My point stands to your 'body part' comment. I feel like I did answer your statement. No big skill needed for HO to test the door. We just have to follow manufacturers instruction. Cuz the doors will cause damage, treat them with respect, like any other mechanical device.
But, as every other tradesman does, we do a little reverse engineering. I know that by sticking my hand under that door (standing outside) and creating some resistance I should be able to get it to auto reverse. I also get to see the door move on its bogies. And if it doesnt work and if its got a photo sensor at the bottom I sweep my foot to re-open the door.

Originally Posted by Corey Friedman

Stephen,

Elevator doors are specifically designed for that function.

Battle tanks and bomb doors... really? Kinda specialized including specialized training.

Corey

Bob,

I am going to go out and purchase a 6 footer 2x4 today. I just hope it fits in my inspection kit.

Crap happens in this business. Honestly, things break when we are doing inspections. I have had a main water shutoff break off and start trying to convert the crawlspace to a trout pond. I have had several windows fall out when I tried to open them. I had a furnace catch debris in the ducts on fire (the fire department said it was a good thing that I was the one this happened to because I shut the furnace down properly, but I sure didn't feel like it was such a good thing) I have never had to fill out an insurance form or even offer any more explanation than "component failed under normal use or industry accepted testing." C'mon guys, this is a business where we are suppose to find failing or problem components to protect our clients. To do that, we have to risk breaking things.

I had quit using the wood block because of one problem door some 14 years ago. In the four days that I have once again been using a wood block, I have had two doors pass the hand test and flunk the block test. (Second one today) Neither door buckled, they just locked the block down.

Since, the wood block test is an industry recognized and approved test, in worst case scenarios, I think you could find yourself doing more "splainin" about why you didn't use it than why you broke a door using it.

This thread morphed into something very interesting about our business and the way we conduct it. Jerry noted situations where he won't use the block test. I concur. Similarly, I will never test AFCI breakers in an occupied house, which I rarely see these days. As we become more experienced, we have to recognize when and when not to risk breaking something. But guys, if your risk threshold is too low, I don't know how you can effectively do this business.

Of course, that is very subjective and one good thing revealed in threads like this, is how much thought so many inspectors put into the way they conduct their business.

Originally Posted by Stephen G

Talk to what you know, In my past life I was a heavy armoured mechanic and frequent elevator door tester, just like you.
My point stands to your 'body part' comment. I feel like I did answer your statement. No big skill needed for HO to test the door. We just have to follow manufacturers instruction. Cuz the doors will cause damage, treat them with respect, like any other mechanical device.
But, as every other tradesman does, we do a little reverse engineering. I know that by sticking my hand under that door (standing outside) and creating some resistance I should be able to get it to auto reverse. I also get to see the door move on its bogies. And if it doesnt work and if its got a photo sensor at the bottom I sweep my foot to re-open the door.

Hi Stephen,

First of all, I really don’t care how anyone tests the doors and never said otherwise. As I said in my post, everyone should do what they believe is best for themselves and their client.

We’ll have to agree to disagree on elevator doors, but you did indeed answer that question.

I know very little about tanks and never said I did (know anything about tanks). I was asking a question (hence the use of a question mark) but that’s ok if you didn’t understand what I meant. I also assumed that people involved in the operation of tanks had specialized training, apparently not. Thank you for clearing that up. I appreciate your input based on your previous tank experience.

Is it safe to assume that you served in the military or some type of military support? If you did, thank you for your service.

Have a great weekend.

Corey

Originally Posted by Raymond Wand

Bob,

I am going to go out and purchase a 6 footer 2x4 today. I just hope it fits in my inspection kit.

Bob,
I cut my 6 footer into 1 foot lengths. Fits fine now, though I had to take everything else out to make room.

Bob E.,
Block of wood is is more of a measurement devise than anything else. Though I agree on selling more product.

You stated :"...If it is a 12-14 Lb retract setting then my hand method is a much better judge than a solid block of wood damaging a door and also does what the block can not which is make sure it retracts on light pressure not to mention very few kids are one inch tall. ..."

If you can get a manufacture or a U.L. source to specify the force expected to trigger the reverse I would love to know it. I am trying to get a manufacture to provide PSI specification but have not to date.

Lon,
"...I have had two doors pass the hand test and flunk the block test. (Second one today) Neither door buckled, they just locked the block down...."

Passing the hand test help ensured that the door would not be damaged using a 2x on the floor.

Your situation of the door operator failing the 2x test is a matter of the adjustment to the travel distance of the door
Did you try to turn the 2x4 on edge and parallel to door? Or add a 2nd 2x to increase height?

Corey,
".......I am curious how you think an ergonomic professional, back doctor, P.I. lawyer and OSHA would respond if you asked them following:

Do you think it is a good idea...."

If you listened to them it would take 4 people, 3 supervisors, 12 form, 2hours of paper documentation and 14 hours of certification training to put up a 40 ft ladder. Oh I forgot the crane and operator.

I typically find most (not all) doctors and lawyers hire others to perform anything requiring actual physical labor. They do not want to risk getting hurt. Plus the work up a sweat issue.

With trying to stop the door using your hand, instead of your shoulder, if the force is to great you just let go. No harm no foul. No worse than picking up a 50# bag of bird seed or a 75+# ladder. How about a bundle of shingle?

Inside garage, outside garage, on roof to test door operation.
If after during an inspection of a door I had a concern of it falling down on me I would have already stopped inspecting and declared it as failed and in need of repair. I have never had a concern of a door coming down on me that I have determined in sound operating condition. If a door is going to come down it will be for a reason. It is my job/responsibility to determine the risks and act accordingly. That is what knowledge and experience teaches you. Knowing what to look for and test then what those thing actual mean.

The block test doesn't work sometimes because on the bottom of the door is a rubber seal which will help seal floor inconsistenties. It can hide an uneven surface by about an inch or more as it should. Sometimes the installer sets the door down only enough to hide the crack to keep daylight from shining through. I would like to say that extensive testing and calibration is beyond the scope of a standard home inspection.

Ray,
Right you are. There are at least 3 different bottom door seals to use, one is extra large to compensate for sloping openings. The large one can be a problem to set to.

"....extensive testing and calibration is beyond the scope of a standard home inspection."

I do not think anyone is saying to reset/calibrate the operator or to make any adjustment to the door. But, unlike many things in the house that are inspected devoting the time required to the garage door should not be question. State and organizational SOP will give you potentially a partial pass on how well you inspect the door and operator systems. But, it may come back to bite you. Also, if only to protect the unknowing (ignorant) from themselves, a real close and extensive inspection may prevent damage to property and injury to others. There are few areas that have so many things involved in the installation and subsequent operation.

Originally Posted by Garry Sorrells

Bob E.,
Did you try to turn the 2x4 on edge and parallel to door? Or add a 2nd 2x to increase height?

That is a good question but, it is not the industry recognized protocol. I think a much better test would be a 2X4 or 2X6 on edge. This is much closer to a child or pet getting stuck under the door, but none of the smart guys who make up these testing guidelines have asked me.

So, do we want to take on the burden of creating our own test protocol? I bet few of us are willing to take on the liability of creating our own protocol for doing a radon test. So why do you cheerfully create your own for testing a garage door. Do any of us think that a garage door is less important than radon and therefore it doesn't matter if we think up our own test procedure?

That kind of thinking takes you into dangerous liability ground. And that is the argument from some of you guys that convinced me to go back to the block test. Inspecting beyond an industry test is fine, imo. But that doesn't mean ignoring the flat 2X4 test. So, what do you tell a client when the door passes a 2X4 on edge test but fails the flat 2X4 test? The opener flunked the industry accepted test. It's educational and informative that the opener passed the board on edge test, for us as inspectors, we better write the opener up as failed. Or...........explain to the customer for minutes why the test is stupid.....just for a durn garage door opener!

Heck, I wouldn't believe that we are still discussing this, except the bigger picture discussion is about whether as lowly home inspectors, do we create our own testing procedures for components that have industry recognized and accepted procedures?

Lon,
Turning the 2x on edge would just have been an answer to my personal curiosity to see that it would make a difference.

The test for 1" to 1.5" is what you would report.

As far as creating individual methodology for testing, Radon testing is Federally regulated. Garage doors seem to be in a bit of a limbo land. Else there would be a specific SPI for the reversal function not just a location for reversal ( 1" from floor). And no specification of the material density to be used for the test. There are no universally specified methods for checking rail attachment. Typically it reverts back to manufacture installation specifications. And not all manufactures write the specs. the same.

Yes it is interesting that the thread has lasted. All revolving over the concern of damaging a door during testing.

Originally Posted by Garry Sorrells

Lon,
As far as creating individual methodology for testing, Radon testing is Federally regulated.

Not to get us going in a different direction, but radon testing isn't Federally regulated. The EPA doesn't mandate anything to do with radon. They just make recommendations. Some states have created licensing for radon testers but not Colorado where I live.

Where Can I Get a Radon Test Kit? | Radon | US Environmental Protection Agency

However, as we know, the EPA has recommended protocols for radon testing and if you don't want to have a discussion with a plaintiff's attorney about it, the course of least resistance is to conduct your radon testing according to the EPA protocol.

You make a good point about different garage door manufacturers and opener makers having differences but the block test appears to be universally accepted by the industry as a test method. I like simple tests but I am not a fan of this one. If I was creating a test, I would have a 4-6" spring with something like 12-15psi resistance. And make my fortune selling them to fellow inspectors, retire to a tropical island and .................or not.

Found a little something from your friends at nachi. .
Thought that Jerry P. would like their illustration of testing from the interior of the opening.

http://www.nachi.org/garage-doors-openers.htm#ixzz1sOV1Uyj1

Inspecting garage door.

The original question of the post: "Is there a minimum / max pressure for the physical retracting mechanism, not the lower eye."

There is an answer.

Thinking there should be a specification in PSI to trigger reversal from obstruction contact, even though it may not be referenced to by manufactures in their installation, operation or maintenance manuals due to the equipment required perform such a test.

After reviewing Underwriters Lab and Consumer Product Safety Commission and then consulting a Senior Project Engineer at UL this is the short answer. [ a little CYA ] (( all should look at the full texts in their original forms and not use the following as their final reference))))

There is no PSI specification for doors without an edge sensor.
The anti-entrapment standard for the door is one that requires the door to reverse after 2 seconds and retract a minimum of 2 inches. There is no min/max specification on the amount of force exerted during those 2 seconds.

An operator using an edge sensor on the bottom of the door does require a pressure 15 lbs. or less to activate the sensor switch.


The following is condensed and highlighted for the areas of interest in this topic area.

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. See Figure 36.1.
36.1.1.1 When installed on a representative commercial 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 commercial 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 at a distance of 6 in (152.4 mm) from the fully closed position. See Figure 36.1.
36.1.2 With respect to the test of 36.1.1 and 36.1.1.1, the test is to be repeated at various representative points of the edge sensor across the width of the door.

Consumer Product Safety Commission

PART 1211—SAFETY STANDARD FOR AUTOMATIC RESIDENTIAL GARAGE DOOR OPERATORS

http://www.gpo.gov/fdsys/pkg/CFR-2012-title16-vol2/pdf/CFR-2012-title16-vol2-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.

(b)(1) A solid object is to be placed on the floor of the test installation and at various heights under the edge of the door and located in line with the driving point of the operator. When tested on the floor, the object shall be 1 inch (25.4 mm) high. In the test installation, the bottom edge of the door under the driving force of the operator is to be against the floor when the door is fully closed.

(2) For operators other than those attached to the door, a solid object is not required to be located in line with the driving point of the operator. The solid object is to be located at points at the center, and within 1 foot of each end of the door. ….

(f)(1) An operator, using an inherent entrapment protection system that monitors the actual position of the door,…….. The entrapment protection system shall monitor the position of the door at increments not greater than 1 inch (25.4 mm). …..

§ 1211.8 Secondary entrapment protection requirements.
(a) A secondary entrapment protection device supplied with, or as an accessory to, an operator shall consist of: (1) An external photoelectric sensor that when activated results in an operator that is closing a door to reverse direction of the door and the sensor prevents an operator from closing an open door,
(2) An external edge sensor installed on the edge of the door that, when activated results in an operator that is closing a door to reverse direction of the door and the sensor prevents an operator from closing an open door,……..

§ 1211.9 Additional entrapment protection requirements.
(a) A means to manually detach the door operator from the door shall be supplied. The gripping surface (handle) shall be colored red and shall be easily distinguishable from the rest of the operator. It shall be capable of being adjusted to a height of 6 feet (1.8 m) above the garage floor when the operator is installed according to the instructions specified in § 1211.14(a)(2). The means shall be constructed so that a hand firmly gripping it and applying a maximum of 50 pounds (223 N) of force shall detach the operator with the door obstructed in the down position. …..

§ 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.

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§ 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.
(2) The test described in paragraph (a)(1) of this section is to be repeated and measurements made at various representative points across the width and height of the door. For this test, a door sensor system and associated components shall withstand a total of 9 cycles of mechanical operation without failure with the force applied as follows:
(i) At the center at points one, three, and five feet from the floor,
(ii) Within 1 foot of the end of the door, at points one, three, and five feet from the floor,
(iii) Within 1 foot of the other end of the door at points one, three, and five feet from the floor.

§ 1211.14 Instruction manual.
……..8. After installing opener, the door must reverse when it contacts a 11⁄2 inch high object (or a 2 by 4 board laid flat) on the floor. …..

As a side note, I contacted many sources one of which was Chamberlain about the SPI specifications to trigger reversal of the door operator.

Chamberlain's response from their technical support was :
"...The travel and force is programmed to the logic board. Using the 2X4 you can check the force reversal. the unit will hit the board and open back up.

Chamberlain does not provide this information, our corporate office considers this information to be proprietary...."

Had a chuckle when I saw it.

Originally Posted by Garry Sorrells

...(( all should look at the full texts in their original forms and not use the following as their final reference))))...



PART 1211—SAFETY STANDARD FOR AUTOMATIC RESIDENTIAL GARAGE DOOR OPERATORS

http://www.gpo.gov/fdsys/pkg/CFR-2012-title16-vol2/pdf/CFR-2012-title16-vol2-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...

(b)...

(1) A solid object is to be placed on the floor of the test installation and at various heights under the edge of the door and located in line with the driving point of the operator. When tested on the floor, the object shall be 1 inch (25.4 mm) high. In the test installation, the bottom edge of the door under the driving force of the operator is to be against the floor when the door is fully closed.

(2) For operators other than those attached to the door, a solid object is not required to be located in line with the driving point of the operator. The solid object is to be located at points at the center, and within 1 foot of each end of the door. ….

(f)...

(1) An operator, using an inherent entrapment protection system that monitors the actual position of the door,…….. The entrapment protection system shall monitor the position of the door at increments not greater than 1 inch (25.4 mm). …..

§ 1211.8 Secondary entrapment protection requirements.


(a) A secondary entrapment protection device supplied with, or as an accessory to, an operator shall consist of:

(1) An external photoelectric sensor that when activated results in an operator that is closing a door to reverse direction of the door and the sensor prevents an operator from closing an open door,

(2) An external edge sensor installed on the edge of the door that, when activated results in an operator that is closing a door to reverse direction of the door and the sensor prevents an operator from closing an open door,……..

§ 1211.9 Additional entrapment protection requirements.

(a) A means to manually detach the door operator from the door shall be supplied. The gripping surface (handle) shall be colored red and shall be easily distinguishable from the rest of the operator. It shall be capable of being adjusted to a height of 6 feet (1.8 m) above the garage floor when the operator is installed according to the instructions specified in § 1211.14(a)(2). The means shall be constructed so that a hand firmly gripping it and applying a maximum of 50 pounds (223 N) of force shall detach the operator with the door obstructed in the down position. …..

§ 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.

(2) The test described in paragraph (a)(1) of this section is to be repeated and measurements made at various representative points across the width and height of the door. For this test, a door sensor system and associated components shall withstand a total of 9 cycles of mechanical operation without failure with the force applied as follows:

(i) At the center at points one, three, and five feet from the floor,

(ii) Within 1 foot of the end of the door, at points one, three, and five feet from the floor,

(iii) Within 1 foot of the other end of the door at points one, three, and five feet from the floor.

§ 1211.14 Instruction manual.

...8. After installing opener, the door must reverse when it contacts a 1-1⁄2 inch high object (or a 2 by 4 board laid flat) on the floor...

Thanks for highlighting/pasting up some of the language from the reference (U.S. Code Federal Regulations) pertaining to the performance testing standards for certification for the manufacture and installation/maintenance instructions required of GDOs and accessory safety features sold for residential installation in this country.

P.S.

Garry,

In the middle of your post (just above 1211.13) you attempted to insert an image directly from your harddrive:

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That, obviously doesn't work.

Could you please upload the image to IN ('attach' it) or to a hosted internet site first, please, so we can see it? After you've first done either, and using a link to same, you can then insert it into your post, if you desire to ('IMG' it), or use the direct link to where the image may be already hosted when you 'IMG' it.

Thanks again.

Missing image