Sensor+ Rack & CEM3: Dimmer Help! Circuits Flickering!

[gafflover87]

Breif Specs: Permanent Sensor+ Rack with CEM3
Houselight circuits are hardwired into 4.8k Dimmers.
Racks are operating at normal temperatures, but about 3 months ago they were giving overtemp warnings every weekend when they would turn off our dimmer and network room air conditioners. This problem was swiftly corrected considering the transformer in the room put off 130+ F, and we havent seen a warming since. But could something have been damaged because of th overtemp, possibly.

The problem:
One of our Houselight circuits is flickering. Doesnt matter whether it has been on for 5 minutes or 8 hours, it will randonly flicker / cut out. Example. Turn it on, its on less than a minute, and will the house lights turn off, turns back on after a few seconds, then turns back off minutes later, then it will turn on and off somewhat rapidly for another 30 seconds. Then it continues with another seemingly random series of flickers and cutting out. Thought it might be because we werent running the house lights at Full, but after playing with it, that theory went out the door.

We are in San Antonio, and Texas Scenic did the install. About 1+ years ago they installed the upgrade package installing the CEM3 into our racks. I called them and they said it could be that the CEM3 is having issues and to reset it. I will try it, but considering it doesnt happen to my other circuits, Im kind of doubting that is the problem.

I have scoured the CEM+ manual, and have found nothing about how to reset the darn thing, do I just pull it from the rack, and put it back in?

Short of switching dimmer packs around to see if one is faulty, have you guys ever had any similar issues.

Trying to avoid calling a tech to come look at it, but I will if I dont have any other choice.

Thanks!

 

[BenTev28]

re: Sensor+ Rack & CEM3: Dimmer Help! Circuits Flickering!

The reset button on the CEM+ is on the upper left. It's the button that looks like the square root symbol.
There are a couple of other potential things to check for as well.

1) How clean is your rack? Even if you're not getting airflow errors reported there could be some issues with dust and blockage. If the screen in the door or the little vents along the right side seem dusty it would be a good idea to clean them out with an air compressor and a vacuum. Make sure the main power to the rack is turned off before pulling out the CEM or depopulating the rack for cleaning.
2) Does the flickering persist if you swap dimmer modules? It's possible that there's damage to the cube in the dimmer card. If the flicker is related to the specific dimmer card and not the slot that it is in then the card can be repaired by an ETC service center.
3) If the problem is specific to the slot and not the dimmer card, is the Sensor configuration set correctly for that card? From your description it sounds like you are using D50 dimming modules for the house lights. Check ABOUT>DIMMER>[DIMMER NUMBER] for the slot having issues and make sure the type is set to D50AF.

Hope that helps!

 

[DuckJordan]

re: Sensor+ Rack & CEM3: Dimmer Help! Circuits Flickering!

another thing to note, just because only 1 is responding that way doesn't mean you don't have a memory corruption issue. Before resetting the CEM3 make sure to have the origional install config file for the CEM3 for that rack on hand on a USB drive. You may need to reload the config for that CEM module after reset. Otherwise call ETC tech support they are darn good at what they do.

 

[chausman]

Careful cleaning and swapping modules are probably the first things to try, with a qualified person, and proper LOTO procedures. That is, if you have at least two D50 modules. Failing that, calling ETC (1 (800) 688-4116) should be the next step. I wouldn't mess with the CEM(s) too much without ETC.

 

[gafflover87]

re: Sensor+ Rack & CEM3: Dimmer Help! Circuits Flickering!

1) How clean is your rack? Even if you're not getting airflow errors reported there could be some issues with dust and blockage. If the screen in the door or the little vents along the right side seem dusty it would be a good idea to clean them out with an air compressor and a vacuum. Make sure the main power to the rack is turned off before pulling out the CEM or depopulating the rack for cleaning.
2) Does the flickering persist if you swap dimmer modules? It's possible that there's damage to the cube in the dimmer card. If the flicker is related to the specific dimmer card and not the slot that it is in then the card can be repaired by an ETC service center.
3) If the problem is specific to the slot and not the dimmer card, is the Sensor configuration set correctly for that card? From your description it sounds like you are using D50 dimming modules for the house lights. Check ABOUT>DIMMER>[DIMMER NUMBER] for the slot having issues and make sure the type is set to D50AF.

Hope that helps!

We keep our rack filters clean, in fact they very rarely seem to get dirty. Havent tried swapping dimmer packs, waiting on one of my techs to come in tomorrow. Im here by myself today, so dont want to be running all over the place, when I can just put him on a radio to make things simple

I pulled our the Dimmer card and it looks good, nothing visibly wrong, atleast nothing I could see. All the Dimmers are configured right on the racks from what I could tell, and yes I should have specified, we have D50AF's.

I will dive into the Rack configuration next if swapping Dimmer cards doesnt work. I keep wanting to call them dimmer packs, becuase of the ancient dimmer modules that Berkey Colortran used to make in the 70's, things were heavy and took up so much space!

 

[gafflover87]

re: Sensor+ Rack & CEM3: Dimmer Help! Circuits Flickering!

D50's are easy to come by, we have 24 of them. Just none of them are extras.

 

[chausman]

D50's are easy to come by, we have 24 of them. Just none of them are extras.

You don't need extras, just swap the module with he had circuit with a know good one. If the problem circuit follows the module, then that is likely part of the problem. If the problem circuit stays the same, then diving into configuration files might be needed.

 

[BenTev28]

re: Sensor+ Rack & CEM3: Dimmer Help! Circuits Flickering!

another thing to note, just because only 1 is responding that way doesn't mean you don't have a memory corruption issue. Before resetting the CEM3 make sure to have the origional install config file for the CEM3 for that rack on hand on a USB drive. You may need to reload the config for that CEM module after reset. Otherwise call ETC tech support they are darn good at what they do.

Double take!! Thanks to Mr. Jordan, I've noticed that the title of the OP says CEM+ but the subject (and body) says CEM3. That's what I get for not paying attention. The information in my post above still holds for CEM3, it's just a little easier to navigate and see what you're doing. It's worth noting that on CEM3 systems the configuration lives in the backplane and not in the CEM. This means that swapping in a new CEM will not require reloading the config, it will get all of that information from the rack. Saving it to USB is still a very good idea - the more backup the better.

 

[DuckJordan]

re: Sensor+ Rack & CEM3: Dimmer Help! Circuits Flickering!

Ben is correct, I was getting my thoughts confused with the earlier version of the CEM's Chases idea of swapping a module will help determine if its a dimmer, (although it could be, as the dimmer heats up it may create a short in the windings which cools and removes the break in the windings.)

 

[jmabray]

Swapping dimmer modules is a good start. Be sure to follow NFPA 70E procedures if you do it while the rack is powered on.

What kind of fixture is it that is doing the flickering?

 

[josh88]

Swapping dimmer modules is a good start. Be sure to follow NFPA 70E procedures if you do it while the rack is powered on.

What kind of fixture is it that is doing the flickering?

Or better, just LOTO the rack before doing it. It's not worth the risk to hot swap something while there is power to the rack.

 

[Aman121]

Maybe you've already checked for this, but are you sure that there isint a problem with the houselight fixture or wiring? A looose connection in a junction box or even in the rack itself would definitly cause flickering. We had a similar case of flickering lights and lights coming up on the wrong circuit, it turned out to be some stray bits of metal that found their way into a large junction box.

 

[JD]

Thinking Power Cube in the module and problem will follow the module. Do tell us the results of the swap.
After the cubes have had enough heat stress (usually measure in lots of years) cracks can develop inside causing the symptom you described.

 

[gafflover87]

So I swapped the dimmers, and the problem seems to be eliminated. I say seems because the problem wasnt persistant at all, some days it would do it nonstop, others it wouldnt happen at all. But yes, the dimmer swap seems to have done the trick. I put it on a circuit that has nothing but some old strip lights. Odd thing is you would expected the problem to travel with the dimmer, but we ran them for hours and never saw them flicker once. So well see what happens. Atleast now I can ease the fears of my administration (were affraid it would do it during out Presidents upcoming lecture lol).

Thanks for the help guys, I let you know if anything changes.

 

[chawalang]

Do you by any chance have a an ethernet node to your dimmer rack. An I/O so it can be sent to the rack as DMX 512? I know you said that your issue was fixed by I have discovered your situation arises when the node is begin's to go bad. Just a thought if the issue returns. Also Im curious what venue this is, Im from SA.

 

[gafflover87]

We have standard ETCnet and can run the dimmers with both ETCnet via cat5 and standard DMX512. Our facility thankfully has some redundancy built in. The channel in question in mostly controlled by the Paradigm, but can of course also be controlled by our board. I will PM you the facility.