Control/Dimming Shut Down Your Dimmer Rack

[StradivariusBone]

So I know this is a topic that has a few threads devoted to it, but I thought I'd share a recent experience. Being a public high school, we were dark for the past few couple weeks. Midway through the break I got a call from a teacher I work with who happened to be walking by the theatre and noticed that lights were on. Long story short, the arch controller had frozen and locked every dimmer on at full. Judging by the decay of our cyc gels and the temperature of the building, lights had to have been burning for some time.

I've shut down the dimmers for extended breaks before, but I was hesitant this time since we've had trouble from recent lightning damage and they're 20 years old- I'm almost afraid they won't power back on after 2 weeks. However, it never occurred to me that they would fail in this way.

We've had this occur before when plugging in a new lighting console (which was weird), but it hasn't happened recently and certainly never on its own before. I replaced the 7517 chip on the arch controller (It's an ETC DAS) and managed to get some functionality back. The stations were locked and doing the communication error blink, leading me to believe it had a part to play in the problem. The weird part is that there weren't any storms that would have preceded this failure, I don't know why it decided to do this.

Anyway, good lesson for powering down everything during long dark periods.

 

[venuetech]

My trouble would be that all house lighting is controlled by the same switch as the dimmer racks.
So nocando.

 

[JD]

Some also don't like the idea of killing a mains breaker, but there is an alternative, especially if house lights are on the same system. Although it consumes a bit more time, shut the secondary breakers off for the dimmers that are not controlling house lights. This will insure you don't end up doing a full house relamp should this happen again.

 

[BillConnerFASTC]

Disconnect the data to the rack, or in my work, the A input - which is used for production circuits - and leave the B input - which I use for architectural. Pretty easy of DMX, harder if all is networked but certainly possible.

If you pulled the power on my systems the emergency lights would come on. I lock that down very tight so any loss on any buss in any rack trips the ELTS.

 

[chausman]

Disconnect the data to the rack, or in my work, the A input - which is used for production circuits - and leave the B input - which I use for architectural.

But this wouldn't help in this situation, since it was the architectural system that caused the dimmers to go to full, not the console.

 

[StradivariusBone]

But this wouldn't help in this situation, since it was the architectural system that caused the dimmers to go to full, not the console.

Correct. It was the arch system that took a dump. Why it reverted to full blast I don't know, but I'm guessing there's some lingering damage from our lightning strike.

Some also don't like the idea of killing a mains breaker, but there is an alternative, especially if house lights are on the same system. Although it consumes a bit more time, shut the secondary breakers off for the dimmers that are not controlling house lights. This will insure you don't end up doing a full house relamp should this happen again.

Unfortunately our house lights are on the same rack. In this case I felt it outweighed the risks of leaving it dark, but we also have high bay metal halide lights that function as psuedo-ghost lights so I felt OK leaving it dark and LOTO'd everything.

So far it seems like we lost a handful of A19's in the house, but I'm sure we'll have a nice bunch of burn outs through this next semester

 

[BillConnerFASTC]

I thought you didn't want to disable house. Kill all inputs. Simpler than killing power. I don't know how the das is powered, but just kill power to it might be simpler.

Could be time to replace das also.

 

[StradivariusBone]

I thought you didn't want to disable house. Kill all inputs. Simpler than killing power. I don't know how the das is powered, but just kill power to it might be simpler.

Could be time to replace das also.

When we had the first issues after the lightning strike it was a communications failure and replacing the 7517 IC on each of the stations and the DAS itself fixed it. After this latest fault I replaced the DAS comm chip and restored some functionality, but the main LCD control panel that's furthest away is working intermittently. I'm wondering if the supply voltage for the stations themselves is having issues that is causing these glitches. It uses some flavor of RS-485 to communicate.

There are two fuses that can disable it temporarily, it looks like one does the main board and one handles the stations. Keeping that off for the time being.

 

[JimP0771]

Now I am no professional but I work at a community theater where I am tech director. We currently use an Lee Colortran ENR 66 Dimmer rack and a Status 24/48 Board. Now I sometimes get the same issue with that. Some times the lights will come on by them selves for no reason Now it is not all of the lights it is like just 1 or 2 circuits. Whet I found out was that being it was a used system that some of the dimmer mods had burned out in the on position and the only way to get the lights to turn off is to turn the breaker on the mod off. So I switched the mods and that took care of the problem. Perhaps some of the dimmer mods in your system have burned out in the on position. In that case if you are able to move mods around just move one that works to that circuit and put the bad one on a circuit that you do not use. However than again I am not professional so I could be all wrong.

Best of luck keep us updated on what happens

 

[EdSavoie]

On the note of actually turning the rack off, I was talking with an electrician who (among other much more serious concerns) pointed out that most of the disconnect switches he's seen aren't rated to open under load, rather you need to turn off everything on the rack and then flip the switch in order to isolate it from mains.