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overhead garage door downforce


ericwlewis
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I've looked around and can't find an answer to my query.

A client I just did a home inspection for on the house they're buying asked me to make a repair he couldn't make himself on the house they were selling. While I was there he asked me this, "Is there a standard on what should make the OHD opener reverse?" We used a brick and the door did not reverse. We used my shoulder and the door did reverse. We used a 12" tall box of diapers and the door did reverse.

What is to be expected? I always use my shoulder to test downforce.

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I've looked around and can't find an answer to my query.

A client I just did a home inspection for on the house they're buying asked me to make a repair he couldn't make himself on the house they were selling. While I was there he asked me this, "Is there a standard on what should make the OHD opener reverse?" We used a brick and the door did not reverse. We used my shoulder and the door did reverse. We used a 12" tall box of diapers and the door did reverse.

What is to be expected? I always use my shoulder to test downforce.

He will find the answer in the instruction manual for his garage door opener.

The universal test is a 2x4 placed flat on the ground. Once the unit has been adjusted to reverse for that, then you can adjust it to be more sensitive as you wish.

The reason that the door will reverse on your shoulder and not on a brick is that the brick is low, near the end of the door's travel, and at the point where the auto-closer's leverage is the greatest. You must adjust for an object low to the ground first. If there's any finer adjustment available after that, great, but the object near the ground is the qualifying test.

Also bear in mind that these things reverse in reaction to amp draw, not pressure. Amp draw is directly related to temperature. So once an opener is adjusted, the pressure it exerts before reversing will CHANGE with the ambient temperature. For this reason, and others, the pressure reverse function is ONLY intended to prevent entrapment, not injury. There is no prescriptive amount of pressure that an opener must exert before reversing.

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For what it is worth, Wikipedia suggests that the downward force can be no more than 15 lbs. (bottom of article).

http://en.wikipedia.org/wiki/Garage_door_opener

No, that's talking about systems that do *not* include safety eyes and that only rely on the force sensor. These systems do not use amp draw to cause the motor to reverse and they always have both the opener and the door itself installed together as a kit.

The liability question always arises in my mind when I am asked questions like this. Best to recommend the Overhead Door Installers.

Some of the most dangerous installations that I find were installed by those guys. I just perform the tests that are in the instructions. For me, that's about the best that I'm going to do at reducing my liability.

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Does anyone else refuse to test downforce?

If it doesn't have the electric eyes, I tell folks to replace the opener. If it's got the eyes, I test them.

Reason being, I've dropped doors off the tracks with the stupid 2x4 test, and I've played with my own door for enough hours to know that the thing can't be adjusted effectively. It'll be in adjustment, then not, then OK.

I didn't realize that could be due to temperature change. Is that right?

Temp change can screw up the force adjustment?

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. . . I didn't realize that could be due to temperature change. Is that right?

Temp change can screw up the force adjustment?

Yes, absolutely. And one of the easiest ways to raise the temperature is to run it several times in a row. As the motor heats up, the downforce becomes more sensitive. So if you have to run it over & over again to get the thing to reverse properly, you'll just be calibrating it for that warm temp. If you come back in a few hours, it's whacked again.

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My boilerplate:

I no longer test the anti-entrapment (reversing) feature of garage door openers. Unfortunately, my experience and research has shown it is impossible to keep these devices properly adjusted. The method most devices use to "sense" the amount of resistance is the root of this problem. The two devices I do recommend for their safety features are Wayne Dalton I-Drives and the Liftmaster 3800. The manufacturer of the device installed at this home recommends you test the feature monthly. You should be made aware that if you do perform this testing, the opener will periodically fail to reverse properly.

I based it upon Jim making the same comment some time ago.

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My boilerplate:

I no longer test the anti-entrapment (reversing) feature of garage door openers. Unfortunately, my experience and research has shown it is impossible to keep these devices properly adjusted. The method most devices use to "sense" the amount of resistance is the root of this problem. The two devices I do recommend for their safety features are Wayne Dalton I-Drives and the Liftmaster 3800. The manufacturer of the device installed at this home recommends you test the feature monthly. You should be made aware that if you do perform this testing, the opener will periodically fail to reverse properly.

I based it upon Jim making the same comment some time ago.

How much does Wayne Dalton pay you?

That's the question I would ask if you put that glowing product endorsement in my report.

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No, that's talking about systems that do *not* include safety eyes and that only rely on the force sensor. These systems do not use amp draw to cause the motor to reverse and they always have both the opener and the door itself installed together as a kit.

If the system has a blocked 'safety eye,' there's no reason for it to come down at all. If that system (safety eye is working.)

Some of the most dangerous installations that I find were installed by those guys.

It is easy to disparage a whole group of people when you don't know who they are.

I just perform the tests that are in the instructions. For me, that's about the best that I'm going to do at reducing my liability.

It either works (intended function), or it doesn't.

Hence the line, "Needs further evaluation by a qualified professional tradesman."

Once you 'diagnose' the problem you open yourself up to be contradicted by "the last man in," who will be the guy who actually does the repair.

Not very good for PR.

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In NY is is illegal to service an opener that doesn't have safety eyes, so I won't even operate it if there are no eyes and just recommend a replacement. If it does have eyes, I ask someone to push the wall button while I break the beam. That's it.

It doesn't really matter though because no one ever thinks to take care of the rest of the door. The springs, rollers, and hinges all need periodic lubrication, at least every 6 months, or something is going to break. Almost every door I see is way over due for a tune up.

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Once you 'diagnose' the problem you open yourself up to be contradicted by "the last man in," who will be the guy who actually does the repair.

Not very good for PR.

Bob, If you serve clients well and provide useful information you can expect to be contradicted now and then. It's part of being a good inspector.

If its your goal to withhold useful information in order to dodge being contradicted in the name of PR, it's my opinion you should change that attitude.

You'll build a better and longer lasting business if you just provide good information and don't worry about being contradicted. Just be ready to back up what you say, thats all.

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I've looked around and can't find an answer to my query.

A client I just did a home inspection for on the house they're buying asked me to make a repair he couldn't make himself on the house they were selling. While I was there he asked me this, "Is there a standard on what should make the OHD opener reverse?" We used a brick and the door did not reverse. We used my shoulder and the door did reverse. We used a 12" tall box of diapers and the door did reverse.

What is to be expected? I always use my shoulder to test downforce.

If you decide to test the reverse function, you're less likely to get into trouble for equipment failure if you use the industry standard testing method.

http://www.ashireporter.org/articles/ar ... px?id=1452

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No, that's talking about systems that do *not* include safety eyes and that only rely on the force sensor. These systems do not use amp draw to cause the motor to reverse and they always have both the opener and the door itself installed together as a kit.

If the system has a blocked 'safety eye,' there's no reason for it to come down at all. If that system (safety eye is working.)

Sorry Bob, I wasn't clear. The 15# limit in the Wikipedia article you cited does not apply to downforce systems that are also equipped with safety eyes. It only applies to systems that do not, by intent and design, have a safety eye at all. For instance, the Wayne Dalton I-drive system, when used with a special Wayne Dalton door does not need to have a safety eye installed at all. This system, therefore, must meet the 15# limit. The same goes for the Liftmaster 3800 series that Charlie mentioned. These systems do not use amp draw to trigger the pressure reverse, by the way.

Some of the most dangerous installations that I find were installed by those guys.

It is easy to disparage a whole group of people when you don't know who they are.

Sure I know who they are. They leave their little stickers right there next to the control button that they installed too low. In fact their stickers are in the exact spot where they failed to place the required warning sticker. They regularly install the safety eyes too high too.

At any rate, my intent isn't to disparage them, it's to illustrate that referring my client to an auto opener installer isn't always the best way to serve my client's interests. It's a perfect example of trying to cover your own butt at the expense of your client's butt.

I just perform the tests that are in the instructions. For me, that's about the best that I'm going to do at reducing my liability.

It either works (intended function), or it doesn't.

Hence the line, "Needs further evaluation by a qualified professional tradesman."

Sorry if I misunderstood your point. I was responding to your statement, "The liability question always arises in my mind when I am asked questions like this. Best to recommend the Overhead Door Installers." I took the statement to mean that you don't offer an opinion about how a closer should work.

Once you 'diagnose' the problem you open yourself up to be contradicted by "the last man in," who will be the guy who actually does the repair. . . .

I diagnose problems every day of my working life. But I'm careful to limit the diagnosis to what I know to be true and to limit my speculation to things that I'm really, really confident about. Contradictions by the last man in have not been a problem for me so far. Maybe tomorrow, though . . .

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In NY is is illegal to service an opener that doesn't have safety eyes, . . .

What about those openers that are designed to operate without safety eyes? They aren't common, but there are doors with leading-edge sensors, and there are openers that measure the tension in the operating cables. Both of these are in lieu of eyes. The systems are UL listed and meet all federal standards. Does NY State not recognize them?

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Wayne Dalton is in the business of over-simplifying overhead door components to the point that they are disposable rather than serviceable. They simply don't work over the long haul. At least that's my experience.

I haven't seen any commercial style pneumatic edge doors in residential use. I'll have to check out the LM 3800.

The NY rule is to prevent OHD techs from repairing, or reconnecting to replacement doors, old openers that do not have current safety systems built in. Technology always outpaces the law.

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Hi,

Late to the ball. Everything you need to know is in 16CFR1211 - SAFETY STANDARD FOR AUTOMATIC RESIDENTIAL GARAGE DOOR OPERATORS. These are the testing parameters mandated by the government that the overhead door manufacturers must use and they are not meant as the defacto standard for us; however, at least one of their tests can be effectively performed by home inspectors.

Most overhead door operators I've spoken to don't even know what 16CFR1211 is; and of those who do none that I'd talked to had ever seen it.

16CFR1211.7 - Inherent entrapment protection requirements - covers the standard test. It's a 1" high object placed flat on the floor. A 2 by 4, a half-liter water bottle 3/4 filled with water, a maglight all can approximate that test pretty well.

16CFR1211.12 - Requirements for edge sensors and 16CFR1211.13 - Inherent force activated secondary door sensors cover requirements for doors - not just gates, the gate standard is a different CFR - that have a built in force-activated edge sensor. The standard is 15 lbs or less while closing and 25lbs or less while opening. In my opinion, there is no practical way you can test this in the field; not just for the reasons mentiioned by Jim, but because the test is very specific and requires special test objects depending on what type of door one is using, so, just use a 2 by 4 or the other objects I mentioned above and you'll be testing the door about as well as you can under field conditions.

16CFR 1211.11 - Requirements for photoelectric sensors used to state that openers could not be mounted higher than 6-inches off the floor but were revised in 2007 and now defer to manufacturer's instructions. The standard does still require that the sensors detect a white object 6 inches high by 12 inches long placed at three points in the opening - one foot from each end and at midpoint. I think this is an easily done test. A simple plywood stand 12-inches long by 6-inches high painted white can be made for pennies and will look very professional.

ONE TEAM - ONE FIGHT!!!

Mike

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Hi,

Late to the ball. Everything you need to know is in 16CFR1211 - SAFETY STANDARD FOR AUTOMATIC RESIDENTIAL GARAGE DOOR OPERATORS.

The standard does still require that the sensors detect a white object 6 inches high by 12 inches long.

ONE TEAM - ONE FIGHT!!!

Mike

Thanks, Mike. Seems to me your dog would make a good little door tester. [:)]
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I think it's OK to tell customers about the products that you trust and use. I do.

I'd never put it in a report though. It's mildly unseemly, and it's another data point to confuse my already disinterested customers.

Most of my folks are going to buy whatever it is the salesman has in stock at the time of purchase anyway.

I think stuff like that is better put in blogs or other information offerings. The report should be just the facts.

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Not bad thoughts to ponder. I see the merit. I do receive positive feedback for the effort.

I'm revamping my report, switching to HIP in the process, to emulate your reporting method in concept. I've debated the use of links to my website as part of the report to provide additional information.

Thanks for the thoughts.

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Now, links to info is cool. It is the future.

Why should I talk about product, or anything I don't fully understand as well as I might, or that might be tangential?

It's like having a boilerplate about concrete in the report. I'd rather just link to the Portland Cement Association, or similar stuff appropriate to whatever I was reporting on.

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Hi,

Late to the ball. Everything you need to know is in 16CFR1211 - SAFETY STANDARD FOR AUTOMATIC RESIDENTIAL GARAGE DOOR OPERATORS.

The standard does still require that the sensors detect a white object 6 inches high by 12 inches long.

ONE TEAM - ONE FIGHT!!!

Mike

Thanks, Mike. Seems to me your dog would make a good little door tester. [:)]
Hmm,

You know, you're right. Peanut is just about that size. The problem is that the tests aren't designed to reduce pressure, only ensure that the door retracts. He weighs about 3 pounds 10 ounces and one of those doors would flatten him like a bug.

Click to Enlarge
tn_20119711634_peanut2.jpg

42.24 KB

ONE TEAM - ONE FIGHT!!!

Mike

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