ETC Sensor 24 dimmer issues

[disc2slick]

Hey guys,

I've been stumped about this issue so I thought I'd send it out to the larger community. This is a problem a friend has been having with the dimmers at his theater. I have been out there once to try to sort it out, and have also been on the phone with ETC about it.

The problem is that dimmers will fail to come on, and/or come one when they are not supposed to in a flicker-y manner. So, sometimes when you bring up a cue dimmers will not come on, sometimes when you are setting in a cue dimmers will get brighter, or dimmers that should not be on will come on.

Here is the system:
ETC 24/48, running through an opto to 3 sensor 24 (CEM+) racks (into 1 rack daisy chained to the next 2). Also coming out of the opto are 2 Icues. In one instance there are 4 dimmers patched to the same channel, of which only 2 are affected.

So far we have:
-swapped out all the dmx between the console and the dimmers, as well as between the dimmers themselves
-terminated the last dimmer with the onboard termination switch (it was not engaged when i inherited the problem)
-swapped out the console
-cleaned all the dirt and crap out of the dimmer cards and brains

Things we know:
The problems are not confined to 1 rack
problems are not confined to 1 phase
problems seem to get worse as the day goes on (I'm thinking temperature issues)
problems seem to start with the same 2 dimmers and then spread
when i took the cards out to clean them a few seemed warmer than i would have expected
In one instance there are 4 dimmers patched to the same channel, of which only 2 are affected.
Problems will go away for a day or two at a time and then come back
phases are reasonably balanced

I spoke with ETC the other day and they agreed that terminating it and cleaning the dust out should fix it. But I just got a text this afternoon saying the issues were back.

Thanks everybody!

Dan

 

[chawalang]

Hmmm do you have another opto to possibly swap??

You did not mention it but just to check do you have a node anywhere converting ethernet to DMX to the racks?

My first thought was possibly a bad node, I have seen something similar happen twice before and it was a bad I/O node.

 

[disc2slick]

Hmmm do you have another opto to possibly swap??

You did not mention it but just to check do you have a node anywhere converting ethernet to DMX to the racks?

My first thought was possibly a bad node, I have seen something similar happen twice before and it was a bad I/O node.

no nodes, just straight DMX. we don't have a spare opto, but I'm told they tried taking the opto out of line completely and it didn't help.

 

[DavidNorth]

It's is indeed odd that it is happening across all three racks and all three phases, but the good thing is that it is reasonable to assume that it is not CEM+ modules or dimmer modules unless a lightning strike has affected everything. So, what is still left in common with all three racks that has not been replaced. Well, I would suggest the splitter, the power feed and the circuit wiring.

A few questions.

Are these installed racks or portable packs?
What is the circuit layout from the dimmers to the fixtures?
Is the circuit wiring all portable cable, multi-cable or hard wire strips?
If strips, are they older or were they put in new when the dimmers were put in?
Are there any other issues in the building? Computers rebooting, elevators stop working, worklights dim or get bright?
When the lights change levels, do the fans on the racks change in volume or audio frequency?
Have there been an unusual number of lamp failures from time to time?

I have several theories but let's start down this path first before we start making some statements.

David

 

[disc2slick]

It's is indeed odd that it is happening across all three racks and all three phases, but the good thing is that it is reasonable to assume that it is not CEM+ modules or dimmer modules unless a lightning strike has affected everything. So, what is still left in common with all three racks that has not been replaced. Well, I would suggest the splitter, the power feed and the circuit wiring.

A few questions.

Are these installed racks or portable packs?
What is the circuit layout from the dimmers to the fixtures?
Is the circuit wiring all portable cable, multi-cable or hard wire strips?
If strips, are they older or were they put in new when the dimmers were put in?
Are there any other issues in the building? Computers rebooting, elevators stop working, worklights dim or get bright?
When the lights change levels, do the fans on the racks change in volume or audio frequency?
Have there been an unusual number of lamp failures from time to time?

I have several theories but let's start down this path first before we start making some statements.

David

-portable racks
-all multi cable running out of the racks, straight socapex out
-i have been told that they had some fairly major electrical problems in the building a while ago. I don't recall the nature though, they share some of their power with the MTA (NYC Subway) and I think there was some kind of power surge. The same theater has a whole bunch of fluorescents with blown ballasts from, presumably, the same electrical incident.
-the dimmers are in a different room than the theater so I don't know if the fans operate differently while the lights change levels.

Dan

 

[DavidNorth]

If possible, I'd like to suggest that the next time this happens, someone goes to the About Rack Power screen on the CEM+ modules and see if the voltage looks incorrect on some of the phases. If so, you have a loose neutral connection.

Another option is to have an electrician come in and make some measurements on the feeds while various levels are being set on the racks. The phase voltage should stay the same at different lighting levels as it does when nothing is turned on. If not, turn off and lock out the feed panel and have the electrician check all the connections.

David