Another garage door tragedy

[Dan Harris]

Maryland girl, 3, dies after being pinned by garage door, deputy says | Fox News


What a sad story.

For years I've been writting up the height of the opener button on new and re-sale homes.
I lost track of how many times the builders reps gave me crap for writing it up, and or they down played it to the home owners.
It took apx 5 years for the builders, after I started including the Gov and Mfg. installation requirements, to start raising them to 5'or higher.

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[Steven Turetsky]

Is the fault here that the button was too low, or that there was no safety sensor(s)?

[Rick Cantrell]

To the inspectors that do not test the garage door automatic reversal safety feature
Read this (read it even if you do test)
62 deaths involving garage door openers

http://www.cpsc.gov//PageFiles/117849/gdoupdate.pdf

[Gary DeWitt]

I note button height and test BOTH reversal systems,height of electric eyes, check the weight without opener, all fasteners, rust on spring(s), presence of manual handle inside.
How can someone purport to protect their client without at least that?

[Steven Turetsky]

Many years ago, I was standing inside a garage behind the person that was raising the door. When the door was about 3/4 raised; the wheels of the top section came off the track and the section swung down. It hit me in the head and knocked me on my ass.

Well, I'm sitting here laughing about it now... lucky me.

So I would like to add carefully checking the wheels/operation.

[Jerry Peck]

Is the fault here that the button was too low, or that there was no safety sensor(s)?

I would say the fault for that was at least three things:
- "

Authorities believe she may have pushed the garage door's control button and tried to run out of the garage. Richardson said the door apparently struck the girl's back and pinned her.

"

- 1 The button height was too low and allowed the little girl to be able to reach it.
- 2 There were no photo cells to detect when she ran under the door, which would then automatically reverse the door, not trapping her.
- 3 The auto-reverse did not function properly, leaving her trapped under the closed door.

Steve,

I've had garage doors raise up and then be pulled too far up and fall off the open end of the track. I've also had garage doors fall due to the tracks not being parallel, the upper ends were wider than the vertical section of the track, this allowed the track to 'pull the axles and wheels out of their carriers' which allowed the doors to fall. Each of these have been found new homes as well as new construction homes.

[Steven Turetsky]

I would say the fault for that was at least three things:
- "

Authorities believe she may have pushed the garage door's control button and tried to run out of the garage. Richardson said the door apparently struck the girl's back and pinned her.

"

- 1 The button height was too low and allowed the little girl to be able to reach it.
- 2 There were no photo cells to detect when she ran under the door, which would then automatically reverse the door, not trapping her.
- 3 The auto-reverse did not function properly, leaving her trapped under the closed door.

Steve,

I've had garage doors raise up and then be pulled too far up and fall off the open end of the track. I've also had garage doors fall due to the tracks not being parallel, the upper ends were wider than the vertical section of the track, this allowed the track to 'pull the axles and wheels out of their carriers' which allowed the doors to fall. Each of these have been found new homes as well as new construction homes.

Hi Jerry,

My very thoughts.

[Stuart Brooks]

Or maybe the auxiliary IR sensor was placed up near the top of the door. I believe someone posted a picture of that a while back.

I check all garage door openers for automatic reversal. Only about 20% are properly adjusted to reverse on contact with a 1.5 inch object. Less than 1% have the warning poster at the switch or have the switch mounted high enough. I've run into builder's or project manager who don't like the labels and I believe that minimum 5 feet height for the switch is from the nearest stand-able surface not just the floor. So, to me that is usually the door sill.

[Jim Starkey]

We can do everything right but still not stop stupid!

[Michael Thomas]

People do truly astonishing things with regard to garage doors.

At an inspection last week in a garage with structural concrete roof someone had cut down and installed a conventional garage door opener between a beam cast into the roof and the vehicle door.

The result was garage door with a maximum opening height of 64".

[Jim Starkey]

Yes I did but I am not sure if it was here or at InterNachi. Point being is that if it does not reverse with appropriate pressure it must be noted and adjusted by a Professional door Installer.

Per manufacturer's instructions is the term I use but either would suffice.

[Mike Clarke]

Years ago an electronics engineer friend of mine had made his own customized door opener before many regulations. He had several safely systems beyond what would be require today, but one thing I had noticed is that one had to be constantly pushing a button for the closing action like a dead man switch, Would automatically open but had to be standing there watching when closing. Also had several limit switches and photo eyes for safety, But thought the requirement to have to hold the button in to close the garage door was interesting.

[Mike Lamb]

Some folks think this is clever. These are both from last month. I politely write it up as silly and dangerous.

048 SR600.jpg

044GAR600.jpg

[Geoff Hobe]

What are we looking at here? Are those card readers up above the opener? What is silly and dangerous?

[Mike Lamb]

What are we looking at here? Are those card readers up above the opener? What is silly and dangerous?

Those are photo electric reverse sensors mounted on the ceiling.

[Jim Starkey]

Those are photo electric reverse sensors mounted on the ceiling.

I see this set up on occasion and always write it up. Major no no.

[Jim Hintz]

Many years ago, I was standing inside a garage behind the person that was raising the door. When the door was about 3/4 raised; the wheels of the top section came off the track and the section swung down. It hit me in the head and knocked me on my ass.

Well, I'm sitting here laughing about it now... lucky me.

So I would like to add carefully checking the wheels/operation.

Exactly why I never test a door if there is a vehicle in the garage....

[Garry Sorrells]

People do truly astonishing things with regard to garage doors.

At an inspection last week in a garage with structural concrete roof someone had cut down and installed a conventional garage door opener between a beam cast into the roof and the vehicle door.

The result was garage door with a maximum opening height of 64".

Not sure what you are asstonished by. Short door in a short opening with an opener modified to the the structure. Mabe I am not seeing something in the picture/description. Cutting the rod or shorting the chain, is that your astonishment?

[Garry Sorrells]

The girl was not killed by the switch. She was killed by the anti-entrapment/reverse function not being adjusted correctly.

And there are still those that will not test that part of the operator/door function because they are afraid of one thing or another.

[Jerry Peck]

Years ago an electronics engineer friend of mine had made his own customized door opener before many regulations. He had several safely systems beyond what would be require today, but one thing I had noticed is that one had to be constantly pushing a button for the closing action like a dead man switch, Would automatically open but had to be standing there watching when closing.

That is still one option in place of some of the other measures. You can substitute that for some of the other safety features because someone would need to continuously hold the operator button down for the door to keep closing.

[Mike Lamb]

Is there any statistic or news story of a door closer crushing anyone that was installed with an external entrapment protection device which around my parts is a photoelectric sensor? Is that what happened here? I believe this has been a UL requirement for about 20 years.

Without this upgrade, garage doors are death traps.

[Garry Sorrells]

Mike,
From news stories there were sensors present. I hope that the cause will be determined and published. The reports say that investigators are looking into sensors. For me I can not envision how if they were working that the child was trapped. Even if the external sensors were not working the auto contact reverse would have been the fail-safe if it was adjusted correctly.

Girl Killed By Garage Door: Maryland 3-Year-Old May Have Died Of Asphyxiation

Authorities identify Md. girl killed by automatic garage door; death appears accidental - The Washington Post

"...The garage door has sensors on either side, and investigators are trying to determine if it was working properly...."

[Jim Starkey]

I have never seen garage door sensors that if not working the door would operate at all. Has anyone here ever seen sensors not working and the door still would operate? It had to be the placement of them I would think.

[Rick Cantrell]

I have never seen garage door sensors that if not working the door would operate at all. Has anyone here ever seen sensors not working and the door still would operate? It had to be the placement of them I would think.

Sometimes the sensors will be installed or wired improperly.
Such as the photos by Mike in post #14

This can allow the door to operate but defeats the safety feature(s).

[Jim Starkey]

Sometimes the sensors will be installed or wired improperly.
Such as the photos by Mike in post #14

This can allow the door to operate but defeats the safety feature(s).

I understand the placement will be an issue, I mentioned that, that is a given. I'm asking about sensors that are placed correctly but not working, i. e. dead or if you cross the beam they don't reverse the door. I have never seen a garage door with working sensors properly placed not function as intended. If the beam is crossed the door always reverses and if they are dead the door never works. That is my question has anyone ever seen other wise.

[Rick Cantrell]

I understand the placement will be an issue, I mentioned that, that is a given. I'm asking about sensors that are placed correctly but not working, i. e. dead or if you cross the beam they don't reverse the door. I have never seen a garage door with working sensors properly placed not function as intended. If the beam is crossed the door always reverses and if they are dead the door never works. That is my question has anyone ever seen other wise.

I can give an example of how it may happen

One of the sensors emits infrared light (transmitter), the other detects IR light (receiver).
When the receiver does not detect IR light a circuit opens, preventing operation of the door.
Sunlight produces IR light. If sunlight shines on the receiver the door may operate, even if there is an obstruction between the transmitter and receiver. Also, the contact that opens the circuit can stick in the closed position.

[Jim Starkey]

I can give an example of how it may happen

One of the sensors emits infrared light (transmitter), the other detects IR light (receiver).
When the receiver does not detect IR light a circuit opens, preventing operation of the door.
Sunlight produces IR light. If sunlight shines on the receiver the door may operate, even if there is an obstruction between the transmitter and receiver. Also, the contact that opens the circuit can stick in the closed position.

OK... but again, has anyone ever seen this in a real world situation? that is my question.

Not arguing one way or another I just want to know if anyone has ever seen electronic eyes that are not working and the door still opens and closes or if the working beam when crossed did not reverse the door when broken, that's my question. I personally have not and don't know of anyone who has so I would like to hear if anyone on this forum has.

[Rick Cantrell]

OK... but again, has anyone ever seen this in a real world situation? that is my question.

Not arguing one way or another I just want to know if anyone has ever seen electronic eyes that are not working and the door still opens and closes or if the working beam when crossed did not reverse the door when broken, that's my question. I personally have not and don't know of anyone who has so I would like to hear if anyone on this forum has.

Yes, it can and does happen, not often, but I have seen it.

[Jim Starkey]

Yes, it can and does happen, not often, but I have seen it.

Which have you seen the dead beams/working door or the crossing the beam and no reverse or both? I really have never seen either situation and have tested a good 2,000 doors or more.

[Rick Cantrell]

Which have you seen the dead beams/working door or the crossing the beam and no reverse or both? I really have never seen either situation and have tested a good 2,000 doors or more.

A little bio of my experience. I have installed burglar alarm systems since 1986

Some alarm systems use photo beams.
These photo beams are more sophisticated, but very much like the photo beams used in a garage door.

I have found both conditions I spoke about;
(1) Contacts sticking. Because the contacts are closed even when there is an obstruction there is no effect. (I describe the contacts sticking, however it could also be the relay or control circuit is defective.)
(2) Sunlight on the receiver mimics the IR light from the transmitter.
Most often this is cause by reflected light, such as sunlight reflected off a shiny car bumper or windshield. Sunlight that shines on the receiver may cause this.
Special precautions are taken to reduce the occurrence of this in alarm systems, however even then, it happens sometimes.
Note: Some (many, most, maybe even all) sensor have a shield and optics to reduce stray light from entering the receiver. These help but do not eliminate all effects of stray light.

Either condition can cause the door to operate even though there is an obstruction.

Have I seen it on garage door beams?
Yes
It was caused by reflected sunlight.
Placing an obstruction between the sensors had no effect.

[Jim Starkey]

A little bio of my experience. I have installed burglar alarm systems since 1986

Some alarm systems use photo beams.
These photo beams are more sophisticated, but very much like the photo beams used in a garage door.

I have found both conditions I spoke about;
(1) Contacts sticking. Because the contacts are closed even when there is an obstruction there is no effect. (I describe the contacts sticking, however it could also be the relay or control circuit is defective.)
(2) Sunlight on the receiver mimics the IR light from the transmitter.
Most often this is cause by reflected light, such as sunlight reflected off a shiny car bumper or windshield. Sunlight that shines on the receiver may cause this.
Special precautions are taken to reduce the occurrence of this in alarm systems, however even then, it happens sometimes.
Note: Some (many, most, maybe even all) sensor have a shield and optics to reduce stray light from entering the receiver. These help but do not eliminate all effects of stray light.

Either condition can cause the door to operate even though there is an obstruction.

Have I seen it on garage door beams?
Yes
It was caused by reflected sunlight.
Placing an obstruction between the sensors had no effect.

Well to be honest the sunlight reflecting off of something would only happen if everything is right at a certain point in time, the sun at the right angle, a car parked a certain way etc, you would have to be there testing it at the exact right time which is way beyond what a home inspection could and typically would find. You could test the same door a thousand times and if not at the exact right time you would never be able to duplicate that situation. So I guess my question is if the sunlight hitting the sensor caused this girls death could a home inspector be healed liable for not disclosing this possibility? I highly doubt it.

The contacts sticking or the board being bad is a real world situation that an inspection could find but then again its like a light bulb, it worked the last 1001 times and the next time it didn't. Just because you tested it and it worked the day of the inspection doesn't mean it cant break the next time the button is hit. Are you then responsible for it breaking and potentially causing harm or death?

I was leaving an inspection once where a kid was playing with a baseball outside next door, I was backing out of the driveway when he suddenly broke a window on the house I just had inspected. Had I left one minuet earlier I wouldn't have wrote it up and probably would have been held liable for missing it even though it wasn't broke while I was there (assuming I left a minuet earlier). That my friends is how fast things can change! We can not protect are selves or our clients from every potential thing in life that may cause harm or death its just the nature of our business. Sleep tight my friends!

[Rick Cantrell]

Yes, both of the conditions I described are very remote possibilities that a home inspector will ever come across.

Yes, sticking contacts would be discovered during a garage door inspection.
And, yes, a system or component can fail at any time without warning.

It is highly unlikely that either of these conditions caused this tragedy to happen.

[Steven Turetsky]

Well to be honest the sunlight reflecting off of something would only happen if everything is right at a certain point in time, the sun at the right angle, a car parked a certain way etc, you would have to be there testing it at the exact right time which is way beyond what a home inspection could and typically would find. You could test the same door a thousand times and if not at the exact right time you would never be able to duplicate that situation. So I guess my question is if the sunlight hitting the sensor caused this girls death could a home inspector be healed liable for not disclosing this possibility? I highly doubt it.

The contacts sticking or the board being bad is a real world situation that an inspection could find but then again its like a light bulb, it worked the last 1001 times and the next time it didn't. Just because you tested it and it worked the day of the inspection doesn't mean it cant break the next time the button is hit. Are you then responsible for it breaking and potentially causing harm or death?

Agreed, which is the reason for the redundancy of the light sensor and the reverse sensor. while it's still possible for failure, the odds are greater.

I was leaving an inspection once where a kid was playing with a baseball outside next door, I was backing out of the driveway when he suddenly broke a window on the house I just had inspected. Had I left one minuet earlier I wouldn't have wrote it up and probably would have been held liable for missing it even though it wasn't broke while I was there (assuming I left a minuet earlier). That my friends is how fast things can change! We can not protect are selves or our clients from every potential thing in life that may cause harm or death its just the nature of our business. Sleep tight my friends!

Once again I agree, but this is why it should be recorded in your report that the system was tested and how it was tested.

[Jim Starkey]

Agreed, which is the reason for the redundancy of the light sensor and the reverse sensor. while it's still possible for failure, the odds are greater.



Once again I agree, but this is why it should be recorded in your report that the system was tested and how it was tested.

In Texas we are required to use the Texas state promulgated form which we have to either mark inspected or not inspected for each item which covers the fact that I either did or did not test it. We are also required to test it per our standards of practice which covers both methods discussed so in essence if I mark the report as inspected and say nothing is wrong it can be assumed that I used both methods as per our standards if practice even though I didn't say anything about it other then marked it as inspected.

[Jerry Peck]

Well to be honest the sunlight reflecting off of something would only happen if everything is right at a certain point in time, the sun at the right angle, a car parked a certain way etc, you would have to be there testing it at the exact right time which is way beyond what a home inspection could and typically would find. You could test the same door a thousand times and if not at the exact right time you would never be able to duplicate that situation. So I guess my question is if the sunlight hitting the sensor caused this girls death could a home inspector be healed liable for not disclosing this possibility? I highly doubt it.

Jim,

"I highly doubt it."

If you are referring to sunlight affecting the opening and closing of garage doors due to sunlight hitting the sensor ...

BELIEVE IT!

Our garage door faces almost due north, one sensor is located on the west side of the door, the other on the east side of the door. During most of the year, at the correct time (which varies during the year as the sun's path changes) there IS a period of many minutes (never sat there and timed it, but it is quite annoying, may even be as much as a half-hour to an hour) where the operator will either not start to close the door, or will start to close the door and then will automatically reverse and open the door. I have two choices: a) go inside the garage and hold the button down to override the operator and be able to close the door, or move a garbage can so that its shadow falls on the west sensor, then the door will close the normal way - but that means I have to stop, get out of the car, move the garbage can, then get back into my car and pull into the garage. A true pain in the neck.

Now, if you are referring to whether or not the sun caused the door to CLOSE ... I also doubt that ... OPEN, yes, CLOSE, no.

[Rick Cantrell]

Jerry
What you describe is quite different than what I described.
And not trying to contradict you at all, but I cannot explain how that could happen.
I'll think on it for a while, maybe even do an experiment or two.

[Jim Luttrall]

Our garage door faces almost due north, one sensor is located on the west side of the door, the other on the east side of the door. During most of the year, at the correct time (which varies during the year as the sun's path changes) there IS a period of many minutes (never sat there and timed it, but it is quite annoying, may even be as much as a half-hour to an hour) where the operator will either not start to close the door, or will start to close the door and then will automatically reverse and open the door. I have two choices: a) go inside the garage and hold the button down to override the operator and be able to close the door, or move a garbage can so that its shadow falls on the west sensor, then the door will close the normal way - but that means I have to stop, get out of the car, move the garbage can, then get back into my car and pull into the garage. A true pain in the neck.

Off the original subject. I know you are a stickler for not changing the listing, etc. but try a tube (think toilet paper cardboard tube) over the business end of the sensor to deflect the ambient light. I've experienced similar issues.

[Garry Sorrells]

I have never seen garage door sensors that if not working the door would operate at all. Has anyone here ever seen sensors not working and the door still would operate? It had to be the placement of them I would think.

Jim,
A reason that the sensors would not function and yet the door would operate lies in the circuit board. Yes it does happen, but very very very infrequently. Most boards are designed to not function if sensor circuits are not functioning. But it still happens. I think Stanley had a problem many years ago. I will check to verify.

Installers will on a service call determine that the door is not operating due to circuit board issue and replace if warrantied, sending board back to manufacture. If not warrantied, usually new opener installed. A DIY installation the home owner just figures the opener is toast and replaces it with a new one. So, the boards that are sent to the manufacture are never heard of again. What the manufacture does with the returned boards,,,who knows. The statistics of type and cause of failure is internal and not published. Again it is not common for a bad board to function and probably the only ones known are the ones that result in an injury or death. I will try to put something together to address the issue of reported sensor failures. Interesting question.

On a personal note I have only seen one case of operator working and sensors not working, just said replace it with a new one. Took it as an freak anomaly and moved on. Now wish I had kept it to play with.

[Garry Sorrells]

To the inspectors that do not test the garage door automatic reversal safety feature
Read this (read it even if you do test)
62 deaths involving garage door openers

http://www.cpsc.gov//PageFiles/117849/gdoupdate.pdf

Is there any statistic or news story of a door closer crushing anyone that was installed with an external entrapment protection device which around my parts is a photoelectric sensor? Is that what happened here? I believe this has been a UL requirement for about 20 years.

Without this upgrade, garage doors are death traps.

Rick's link has the last inquiry selection ending in 2001 and looks like published in 2003. Which made me wounder what has been happening since 2001. Went looking and did not find much. So, I decided to contact CPSC to see what they had on the topic and will report back on results.

A little something to look at more to follow.:

" 72 percent of those doors exerted pressure that was greater than 130 pounds, enough to cause serious injuries like broken bones and organ damage "
STUDY LABELS GARAGE DOORS THREAT TO KIDS. - Free Online Library

[Rick Cantrell]

OK, I've done a little reading (Bonjuor). Seems that sunlight on the sensor is a common problem.
This usually causes the opener not to close.

As much as I can determine this is what is happening.
Similar to old TV shows. When the camera (sensor) sees a very bright light what happens is black spots appear as if there is no light.

[Rick Cantrell]

I think the most important part is the pressure to reverse the door and the spring load.You still can straddle the beam and it can close on you. With proper pressure I think a child still can get pinned but Killed I doubt.

Kevin, I'm not being critical of you however pressure is not what determines if the door reverses.
The door reversal is a measurement of door movement (actually lack of movement) over time (2sec).
This is called the "Anti-entrapment" feature, and is designed to prevent someone from becoming "Pinned" under a door.
This is how the Anti-entrapment feature works.
The door is adjusted to stop at the floor when fully closed.
Anything that prevents the door from fully closing (such as a person under the door), will stop the doors motion.
The door operator senses that motion has stopped before being fully closed and reverses the door.
The operator does not sense force or pressure, it senses movement.
One of the problems with this anti-entrapment feature is the door can exert a great amount of force before it reverses. Enough force to break bones and cause severe injury. For this reason photo beams are installed. The photo beams can reverse the door before any contact is made, thus preventing injury that the door could cause. But, as you pointed out, photo beams are easily defeated. This is why two safety features are installed. Either feature alone does not provide the level of safety needed to prevent injury.

[Garry Sorrells]

Now lets put the DEAD horse in the ground and move on.

Started to say Sorry, but in fact not. Not sorry that this is dead horse will never be put to rest.

Unless the world get a grasp on how potentially dangerous garage doors are. And that for as stupid as it may seem there are many things going on anytime that they are used. So the horse may be put to rest when

[Vern Heiler]

Kevin, I'm not being critical of you however pressure is not what determines if the door reverses.
The door reversal is a measurement of door movement (actually lack of movement) over time (2sec).
This is called the "Anti-entrapment" feature, and is designed to prevent someone from becoming "Pinned" under a door.
This is how the Anti-entrapment feature works.
The door is adjusted to stop at the floor when fully closed.
Anything that prevents the door from fully closing (such as a person under the door), will stop the doors motion.
The door operator senses that motion has stopped before being fully closed and reverses the door.
The operator does not sense force or pressure, it senses movement.
One of the problems with this anti-entrapment feature is the door can exert a great amount of force before it reverses. Enough force to break bones and cause severe injury. For this reason photo beams are installed. The photo beams can reverse the door before any contact is made, thus preventing injury that the door could cause. But, as you pointed out, photo beams are easily defeated. This is why two safety features are installed. Either feature alone does not provide the level of safety needed to prevent injury.

Rick could you point out the motion sensing circuitry? I only know of current sensing.

[Rick Cantrell]

Rick could you point out the motion sensing circuitry? I only know of current sensing.

Please pardon me where I do not describe something accurately. My understanding and knowledge of mechanics and electronics exceed my ability to explain it.

Current sensing is the most common mechanism used to determine if the door is in motion.

If needed I can look up the exact requirements, but basically it is;

The agency that governs the manufacture of garage door openers only state that on contact a door must reverse. They do not describe how this is to be done. Manufacturers decide what mechanism to use to reverse the door after contact.

There are two mechanisms (methods) that most manufacturers use.

A hall effect switch (or something that is essentially the same) , and current sensing.
(Hall effect switches are often used on large commercial gates.)
A hall effect switch directly detects movement.
This is a disk with holes or teeth on it. The disk is connected to the drive mechanism. As the disk rotates, a sensor mounted at the disk detects the holes or teeth as they pass the sensor. If the disk does not turn, there is no movement, and causes reversal.

Most often used in garage door openers is current sensing (easier and cheaper).
Current sensing Indirectly detects movement.
In normal operation it takes a certain amount of current to open and close the door.
If a door meets with resistance, such as worn rollers or an obstruction, the motor produces additional torque to overcome the resistance. More current is needed to create more torque. When current exceeds a certain level, the door reverses.
Current sensing is the mechanism used to determine movement of the door.
When used in this manner current sensing is considered a motion detector.

There is no device that detects motion or movement.
Now, if you want to know more than you really wanted to know, ask me to explain.

added in edit: Actually I can think of one.

[Vern Heiler]

Rick,

The reason I challenged your post, "The door operator senses that motion has stopped before being fully closed and reverses the door. One of the problems with this anti-entrapment feature is the door can exert a great amount of force before it reverses. The operator does not sense force or pressure, it senses movement."

The door does not reverse due to lack of movement but due to exceeding the set current limit. This in my opinion, and in the opinion of the NCHILB, makes the downward force adjustment, or reasonable resistance test, a more valuable test of the door closer than the standard 2X4 test. The entrapment test (2X4) does have value in that it insures the circuitry is still looking for over current until the door within 1 1/2" of closed. After the travel limit (door closed) switch is made, no amount of force will reverse the door.

[Rick Cantrell]

Rick,
The reason I challenged your post, "The door operator senses that motion has stopped before being fully closed and reverses the door. One of the problems with this anti-entrapment feature is the door can exert a great amount of force before it reverses. The operator does not sense force or pressure, it senses movement."

I don't see it as a challenge, but more as an opportunity to better explain my point of view.

The door does not reverse due to lack of movement but due to exceeding the set current limit.

You are correct about it using current sensing. I said it detected motion. Lets look at like this.
We all have seen motion detector lights.
Do they detect motion? Technically, no they do not.
Motion detector lights detect heat, infrared heat. But we do not call them infrared heat detectors, we call then motion detectors. Because in the end, what we want is something that detects motion, not heat. In the same manor we want the anti-entrapment feature of a garage door to detect movement of the door, not the electrical current. It detects when the door stops moving and reverses it.

This in my opinion, and in the opinion of the NCHILB, makes the downward force adjustment, or reasonable resistance test, a more valuable test of the door closer than the standard 2X4 test.

Well Vern, not to be rude, but your opinion does not supercede industry standards and government requirements. All of whice recommend or require reversal testing using a 2x4
And I disagree that a reasonable resistance test is more valuable than using a 2x to test the reversal feature. And that's not just my opinion, but the opinion of manufacturers, and government agency's.
Perhaps you will post the test procedure of the NCHILB.

The entrapment test (2X4) does have value in that it insures the circuitry is still looking for over current until the door within 1 1/2" of closed.

Exactly. I think it very unlikely that anyone could be trapped (pinned) under a door that is open 24" ( Using the reasonable resistance method). But I can easily see that someone could be trapped under a door open 2"-4".

[Jerry Peck]

Off the original subject. I know you are a stickler for not changing the listing, etc. but try a tube (think toilet paper cardboard tube) over the business end of the sensor to deflect the ambient light. I've experienced similar issues.

They keep falling off ... they stick out too far and that is right next to my air compressor, sprinkler pump, etc., I probably need to invent a recessed back sensor holder with flat black baffles projecting forward from the sensor so only light from the other sensor can shine directly into it.

[Garry Sorrells]

Back to the testing for entrapment and reversal of the door operator .....
( a little long for those with in depth knowledge, but hopefully informative for those with less depth)

Glad to see the exchange. Design of the electronics that initiate the reversal function is always interesting and varies from manufacture to manufacture and they really do not want to talk about the actual mechanism that is employed. They seem to think that it is secret to be protected. But, the actual process that causes the door to reverse for most of the HI and others is wasted, interesting but still lost to many.

There seems to be a return to the discussion of testing methodology and philosophy. Not to mention the fear factor, which introduces emotionality to the testing process.

The garage door and operators that are found cover many years of design and development. The newer operators are becoming very sophisticated due to the use of circuit boards and microprocessors. The older ones have fewer function controls which are automatic, meaning that they have to be set and adjusted manually by the installer/user. They were not open the box, install and it will learn the limits during its first run, which the newer ones are approaching. So I would approach the operator as if it were subject to the greatest number of adjustment possible and only have a minimal fail safe design and are old as the hills.

First off there are basically three different requirements dealing reversal and entrapment. 1) the meeting of an obstruction as the door raises, 2) meeting an obstruction on downward movement, 3) Meeting an obstruction at 1" from floor.

The problem is that no manufacture will get involved in a discussion about the amount of pressure exerted by a operator as it closes and what is exerted before reversal is triggers. Just fact, I have tried unsuccessfully. The response is that it is proprietary information.

The reason most likely is potential liability if they were to discuss pressure when they are not required to. Gov regs set the issue in different parameters. Reversal on contact and movement over distance within 2 sec and no force (PSI) is considered to meet specifications.

The 1" (1.5") requirement merrily sets a distance to be observed, had to be set at some distance as a specification to be followed. Could have been at 1/2" or 3/4 or 2" . The discussion/argument that arise boils down to the fact that the Gov regs do not speak to the force (PSI) exerted and in the real world we know by practical experience force exerted can become an issue.

In the process of the function of a doors movement there is a point that the range of movement downward needs to approach the floor and compress the bottom seal of the door. But not to compress the seal to the point that the door is stressed or damaged. This adjustment actually involves two adjustments, 1) range, 2) sensitivity/force exerted.

In practice the door can be adjusted so that it meets the floor and reverses which is not desired. Nor do you want the door to flex/crush under the operator downward force. The trick is to set the range and force as to have a good seal compression against the floor. Then there is the requirement that the door reverse on contact with an obstruction set at 1" from floor, which is by adjusting the sensitivity/force to obstruction contact. This same adjustment will effect the reversal of the door at any point prior to the door reaching the 1" increment form the floor.

Remember. There is no limit (min or max) stated as to the amount of force (PSI) that the door operator can exert prior to reversing, it is a function of time and distance to reverse.

Which is why the older door operators were adjusted to the amount of force required to reverse? Obstructing the door half way in the cycle as it closed by manually grasping the door edge. This allowed the installer to verify/adjust the amount of force required to trigger the reversal. Which was done to prevent damaging the door on full cycle meeting the floor.

The testing procedure of using a 2x4 (1.5"x3.5") block of wood as specified by manufacture has been deemed acceptable by Indep. Labs. and the Gov as acceptable for testing purposes even though the technical specifications state 1''. This is only relevant to the distance from the floor that reversal must occur, again the amount of force on contact is not specified.

Which brings us back to the issue of how to test a door operator for its required (Gov set) specifications. The Government does not care about the potential damaging of the door. That is left to us rational prudent people. We must determine that the door will not be damaged if meeting an immovable/fixed obstruction. That is done by manually restricting the movement of the door during its downward cycle prior to meeting the floor with something that is movable under pressure/force, such as grasping the door with your hand. This allows the subjective evaluation of the amount of force requires to cause the door to reverse or not. Which in turn will allow for the subjective determination of the reversal potential of the door meeting an obstruction at the floor.


Focusing on any one aspect of the door operator specifications is absolutely wrong. The testing of the garage door operator must be done in a holistic approach. The inspection and testing of the installation and hardware is also part of the operation and must be done prior to the operation of the door and the operators' testing. Which is a long and complex discussion which I have not attempted to undertake.

[Garry Sorrells]

Is there any statistic or news story of a door closer crushing anyone that was installed with an external entrapment protection device which around my parts is a photoelectric sensor? Is that what happened here? I believe this has been a UL requirement for about 20 years.

Without this upgrade, garage doors are death traps.

After searching I turned up some reported cases. I am working on getting some other statics and data but it seem that it has to be processed under the freedom of information act process. No simple answer with our government.

NESIS (National Electronic Injury Surveillance System) https://www.cpsc.gov/cgibin/NEISSQuery/home.aspx
code:0138

Number of stated entrapments from 2003 to 2011 : 12 injuries listed.

There were numerous injuries involving the garage door with openers and most involved fingers being pinched or crushed. Which is why they has been a push for doors and openers to be designed to prevent such an occurrence.
The reporting system only provides a limited narrative as such interpretation and extrapolation of causes may be required.


This following are two cases that demonstrated, in a practical application, the reversal function of the door opener on contact. Where the door opener reversed on contact but was not immediate (instantaneous). The child though injured was treated and released. Extrapolating that the opener sensitivity to obstruction (lack of movement of door) was set so as to not cause serious injury.

CPSC Case #: 20538892 Treatment Date: 05/19/2002
Age: 2 - 2 YEARS
Products: 138 - AUTOMATIC GARAGE DOORS OR DOOR OPENERS

Diagnosis: 53 - CONTUSION OR ABRASION
Diag Other: Body Part: 31 - UPPER TRUNK
Disposition: 1 - TREATED & RELEASED

Narrative: PT WAS CAUGHT IN AUTOMATIC GARAGE DOOR WAS LYING ON HIS STOMACH ACCORDI NG TO MOM GARAGE DOOR DIDN'T IMMEDIATELY GO UP DX CHEST CONTUSION ABRAS


CPSC Case #: 90625945 Treatment Date: 06/04/2009
Age: 3 - 3 YEARS
Diagnosis: 53 - CONTUSION OR ABRASION
Diag Other: Body Part: 79 - LOWER TRUNK
Disposition: 1 - TREATED & RELEASED, OR EXAMINED & RELEASED WITHOUT TRTMNT Products: 138 - AUTOMATIC GARAGE DOORS OR DOOR OPENERS
Narrative: MOM CLOSED GARAGE DOOR UNAWARE THAT PT WAS TRYING TO COME IN DOOR. PT T RIED TO CRAWL UNDER, STRUCK IN LOWER BACK W/ DOOR. DX LOW BACK CONTUSIO

[Garry Sorrells]

Stanley Garage Door Openers Recalled Due To Entrapment Hazard

CPSC - Stanley Garage Door Openers Recalled Due To Entrapment Hazard

Originally issued April 19, 1991, Revised October 23, 2002

The company believed, due to a problem with printed circuit boards used in affected garage door openers, the door may open or close without warning. This condition renders the automatic reversal safety feature inoperable. As a result, when the door closes, it will not reverse as intended upon striking a person or object. This poses a risk of injury or death if entrapment occurs. The company reported this problem to the CPSC as soon as it became apparent. The company was not aware of any injuries.

[Russ Olstead]

[QUOTE=Jim Starkey;224317]Which have you seen the dead beams/working door or the crossing the beam and no reverse or both? I really have never seen either situation and have tested a good 2,000 doors or more.

That is why I'm here. Tried to kick under the door while it was closing to get it to re-open because I had forgotten something in the garage and it continued closing. Tested it several times and the reversing sensors would not stop the door from closing. The door went up and down perfectly for I don't know how long. Months, probably. Both LED's were lit, although one of them was quite dim. Upon doing removal and testing, it turns out the sensors had actually failed - would not even work when I cut the wires snug to the opener and had them face to face. I am currently in the process of replacing the sensors.