Channel Stuck?

[Synchronize]

It's quite odd. Channel 15 at my highschool is like possesed. Sometimes, it would just come on in the middle of the night. The wall controls would show the channel as off, but sure enough it was lit up. It would always be off by morning again. But, just recently, it decided not to go off. We were cleaning up after play practice one day, we just turned off the light board and channel 15 lit up. We turned the board back on and it showed no power going to it so we just packed everything away and expected it to be off by morning. Well it wasn't, and wasn't the day after, or the day after that. It was on for 5 days straight and never turned off. We finally turned the light board on, got the big ***** ladder out, and unplugged the light, then replugged it back in. It was off, so we turned on the channel on the light board. It turned on no problem. When we went to turn it off the board showed it as 00 but it looked as though it only backed down to about 70. We tried plugging the fixture into other channels and other fixtures into channel 15. We deduced that it was not the lamp, but the channel. Any ideas what would cause this, or what we could do to fix it?

[Charc]

Failed SSR pack resulting in the dimmer being gated on? Happened at my place. Try swapping your modules.

[Synchronize]

But when its unplugged, the plugged back in, the light stays off untill activated. And once its on, then turned off, it doesnt stay full, it backs down to around 70 and stays there. Its almost as if the channel is only getting part of the signal.

[David Ashton]

It would be unusual for an ssr to be intermittent, usually they blow "on" and stay on.My guess would be a module electronics fault.There is no way it could ever be a lamp fault, it would seem the module is accepting the up signal but is not responding to the down signal, nothing to do but send the module back for repair.

[Synchronize]

By module, do you mean the rectangular box with four recepticals in it? Sorry, I know I'm a total newb at this. Sad part is, I know more about it than anybody at my school .

[David Ashton]

I can only give you a general assessment of the fault, you should not attempt to go any further to fix this problem, it is dangerous to go into dimmer racks unless you know exactly what you are doing, please pass on the information that it is almost certainly a fault on ch 15 dimmer module and have a technician/electrician deal with it.I fully endorse letting students get involved with tech work and it may be useful to watch how to do it but do not at this time do it yourself.

[Synchronize]

So how would I even go about finding somebody to do that? The maintinance dept doesnt know anything about it.

[Charc]

I'll admit I might not have read all of that first post, hence my SSR comment.

[Charc]

David, just noted your post about intermittence. I will note that a had an issue like this, but not replicate-able, just random. It makes me thing maybe this is a data error, levels being sent? Something? It's 3 AM and... yea, sorry I'm of no help.

[gafftaper]

Sync... if your school has an electrician he/she can get parts to fix it, but in my experience they usually don't want to mess with this stuff. You probably just need to have your local theater shop repair it.

Tell us a little more about the dimmer rack. We are assuming you have a dimmer rack that looks something like this. A series of boxes with circuit breakers on the front? The modules may also be short and wide and look more like drawers than boxes like this. It would be really nice if you could post a picture of your rack as we can tell you exactly what you have. Or if you look around to find a brand and model that would be great too.

As David said, messing around inside a rack is an easy way to get yourself killed. I've let students work in my racks but only when a) I'm in the room supervising and b) the power is locked off. So I want to stress that the ADULT in charge of this at your school is the one who needs to take care of this. What they need to do is take the dimmer out of the rack and take it to your local theater dealer and have them repair it. You can have the dealer come to you but it will cost a lot more.

SO here's the plan to SAFELY get this fixed.
-First as noted above, let's figure out what kind of a dimmer rack you have.
-Second if you don't know where the nearest theater repair place is tell us what city you live in and we can help you find one near you.
-Third have the ADULT in charge of the theater call the repair place, tell them what brand/model dimmers you have, and ask for instructions of how to remove the bad module to take it in for repair. Then that person needs to do the actual removal following those instructions.

When you see it removed, you are going to think we are crazy and far too cautious. However, not to insult you, but someone with so little knowledge is taking a HUGE risk by messing with this stuff. Remember if you have a full size 96 dimmer/2.4k rack it is providing 230,000 watts of power and 1,920 amps... it only takes one amp to kill you. So again PLEASE let us help you determine what equipment you have and give you the information to share with the adult in charge to follow the directions of the local repair place.

Others who read this please don't post/P.M. instructions on how to remove a module. Let's keep this young tech alive long enough to learn how to do it the right way from someone who knows what they are doing.