[480sparky]

Tale from the Twilight Zone:

I'm visiting my parents this week for the Thanksgiving holiday. They ask me about an issue they are having with their overhead door opener.

Seems whenever there is a brief power failure (less than one second), the operator opens the door when power is restored. The power is out so briefly that they usually don't need to reset their electronic clocks, so it's a very short outage. However, the door opener, for some strange reason, opens the door.

Obviously, this is a security issue. To mitigate the problem, they climb up on a ladder and unplug the unit if they're going to be gone for any length of time. This, then, becomes a real hassle given their ages (hint: I remember JFK!), constantly open & close the door, climbing ladder and plugging and unplugging.......

The operator is a Overhead Door Legacy model # 496CD/B. Anyone else hear of this problem, and have any solution?

I plan on contacting Overhead Door Monday about this, but I thought I'd post it here to see if I can find a solution.

TIA
Ken

 

[Leo G]

Replace the capacitor in the power supply with a larger one so it can withstand the short power outage.

Does it have a battery backup? Maybe the battery need replacing.

 

[480sparky]

Thanks, Leo.

However, I think changing the cap would only make the time the power is out to cause the problem to change to a longer time frame.

In other words, a 1/10th second outage may cause the door to open now, but changing the cap would only increase that time to, say, 1 second.

It has no battery backup that I know of.

 

[Tinstaafl]

However, I think changing the cap would only make the time the power is out to cause the problem to change to a longer time frame.

Agreed.

Has it always behaved that way, or is it something that developed over time? I wonder if it could be related to the alignment of the obstacle/anti-crush sensors. Regardless, totally unacceptable. Please do let us know how it all plays out--I've never heard of this one.

Meanwhile, throw a switch in to keep them off the ladder. :thumbsup:

 

[480sparky]

Agreed.

Has it always behaved that way, or is it something that developed over time? I wonder if it could be related to the alignment of the obstacle/anti-crush sensors. Regardless, totally unacceptable. Please do let us know how it all plays out--I've never heard of this one.

Meanwhile, throw a switch in to keep them off the ladder. :thumbsup:

It has always been this way. Opener is new to the house, 4 years old.

Adding a switch is one option I thought about doing while I'm here.... it would be easy to do.

 

[Leo G]

If you can't get it to work, instead of a switch use a self holding relay. When the power blinks it will not re energize and the door will not function. Put a push button on the system to re energize the relay and the door power supply. It may be a bit inconvinient but it would be automatic and I think it woul dbe better than the switch which would be fully manual.

 

[JumboJack]

Agreed.

Has it always behaved that way, or is it something that developed over time? I wonder if it could be related to the alignment of the obstacle/anti-crush sensors. Regardless, totally unacceptable. Please do let us know how it all plays out--I've never heard of this one.

Meanwhile, throw a switch in to keep them off the ladder. :thumbsup:

You may be on to something...The power outage could be just short enough to somehow break the beam and therefore some how make the door open.

 

[480sparky]

You may be on to something...The power outage could be just short enough to somehow break the beam and therefore some how make the door open.

If that's true, then I should be able to walk out there, break the beam, and the door will open.

I think they're made to ignore the beam if it knows the door is all the way down.

 

[Leo G]

Adding a switch is one option I thought about doing while I'm here.... it would be easy to do.

Remember to hire a qualified electrician :whistling:w00t:

 

[480sparky]

Remember to hire a qualified electrician :whistling:w00t:

Damn. :blush:

 

[JumboJack]

If that's true, then I should be able to walk out there, break the beam, and the door will open.

I think they're made to ignore the beam if it knows the door is all the way down.

What I'm mean is the power outage is some how breaking the beam and reseting or tricking the senors.

 

[480sparky]

What I'm mean is the power outage is some how breaking the beam and reseting or tricking the senors.

I can't see how that would cause the door to raise. I went out and tried to quickly interrupt the beam, and could not get it to go up. The LED only flashed.

I wonder more if it's causing the control system to 'think' the button has been pushed.

 

[JumboJack]

I can't see how that would cause the door to raise. I went out and tried to quickly interrupt the beam, and could not get it to go up. The LED only flashed.

I wonder more if it's causing the control system to 'think' the button has been pushed.

That's what I am trying to say.:laughing:

 

[480sparky]

That's what I am trying to say.:laughing:

So what does that have to do with the door sensor beam?

 

[mrmike]

This is weird- here is just a thought - it may have something to do with the "down" torque limit control being right on the borderline, & the power coming back on makes that torque limit- sending the door back up-

I would fool with adjusting that-to eliminate that possibility.....................

 

[JumboJack]

So what does that have to do with the door sensor beam?

I was thinking that when the power goes out it some how messes with the sensor beam and trips it.The sensor is more or less a switch also.

 

[Tinstaafl]

It has always been this way. Opener is new to the house, 4 years old.

I have no logical reason to suspect one over the other, but somehow this just smells like an installer malfunction. Mike has a point with the torque limiter also. And usually there's a travel-limit microswitch which needs to be in the right place.

If I had the installation instructions, :laughing: I'd run through all of the setup procedures to make sure they were done correctly before just condemning the unit. There's probably no chance of a warranty fix after four years.

 

[walkerj]

Hey Ken,

Have you tried looking for possibly a nicked wire at the button that is possibly arcing?
Maybe when the transformer in the unit kicks on and off?

 

[MisterCMK]

Install a UPS and forget about it. Why isn't there a switch on the wall to turn off the garage door outlet?

 

[Michaeljp86]

Does these doors have a lock on it that goes through the rail like when you go on vacation? They could just pull the lock in instead of unplugging it.