Sudden dimming trouble

Shawn P

Member
Joined
Mar 11, 2019
Location
USA
Seemingly out of no where, I have an entire bar that is not dimming properly. They are all conventional fixtures on a very old Colortran dimmer rack with an ETC Element console. There is no difference in brightness from 20% to FL. 10% is slightly dimmer, and 1% is very dim, but no where near 1% of the rest of my lights. Between 5-10% some of the lights flash.

I'm leaning towards an electrical problem since it appears to be isolated to just 1 bar. But we're also having trouble with our Element and I'm sending it in to ETC for repair and an upgrade to Windows 7 Embedded, so I don't want to assume it's electrical. I switched off each dimmer's breaker for a minute and switched them back on and that did not fix the problem. I also tried bringing up each circuit individually instead of the entire bar and was able to replicate it. Is there anything else I can try? Could it be a bad fixture or a bad dimmer pack that affects the entire bar?
 

Amiers

Renting to Corporate One Fixture at a Time.
Joined
May 28, 2009
Location
Phoenix, Az
Sounds like that section of the “bar” has a profile attached to the channels that run them.

hit About Channel # and see what information it gives you. If that doesn’t tell you if there is a profile attached to the channel then hit patch and type in the dimmer associated with one of the channels giving you an issue and see what that says.

A storm or a brown/black out could of zapped something and knocked out that batch of dimmers but that seems very unlikely.

A quick troubleshoot would be to load a news show after saving your current and see if the affected channels still present the issue. That would be the fastest way to tell someone fiddled with the console or your dinners are going.

Colortran dimmers are out of my wheelhouse but if it has a control panel of some sort checking there to see what’s going on can also go e you some preview as well.
 

Shawn P

Member
Joined
Mar 11, 2019
Location
USA
Sounds like that section of the “bar” has a profile attached to the channels that run them.

hit About Channel # and see what information it gives you. If that doesn’t tell you if there is a profile attached to the channel then hit patch and type in the dimmer associated with one of the channels giving you an issue and see what that says.
Hey thanks for the reply. I'll check that tonight... not sure who would have changed it but that does make sense.
 

Gobokat

Active Member
Joined
Jan 14, 2015
Location
Chicago
So - Colortran dimmers are pretty much like CD-80 dimmers, are pretty much like 1st gen Sensor racks with MPEs - SCR blocks controlled from a central brain, try swapping trays around in the rack (?) - from what you're describing I'd definitely look at the patch to make sure somehow a custom dimming curve didn't get selected when patching this range of outputs. Then I'd take a look at how neutrals were run to this bar. I'd almost be willing to bet that it's not neutral per circuit and you may have lost a neutral or two and now are experiencing the fun of networked circuits. Has this just recently become a problem or are you just now noticing it? Has anything been changed since you last did a show here when everything worked as expected?
 

Shawn P

Member
Joined
Mar 11, 2019
Location
USA
I went back to an old show file and even created a new one with a 1to1 patch and I’m still experiencing the issue.

We also have a Lee lighting controller for our house lights that I can also use to control the stage lights. That is also showing the same behavior on the same circuits.

I am just now noticing the behavior. We had a concert last week and I don’t recall it being an issue then. It certainly wasn’t an issue in October when we had our play.
 

Amiers

Renting to Corporate One Fixture at a Time.
Joined
May 28, 2009
Location
Phoenix, Az
If you did that and still had the same result then it looks like an dimmer rack issue. That sucks. Like it’s been said try swapping good dimmers with the bad ones and see if the problem travels or stay. That will tell you if it’s the dimmer itself or the guts.
 

Malabaristo

Well-Known Member
Joined
Jul 11, 2008
Location
Wisconsin
If this were a Sensor rack, I would be asking if all of the problematic circuits are all in the top, middle, or bottom third of the rack... can you give more details on which dimmer rack you have? If it's a D192, then the dimmers are arranged in three vertical columns corresponding to the three phases of power coming into the rack. There are also three separate control modules at the bottom of the rack. If all the problematic circuits are in one column, then swapping those control modules would be a good troubleshooting step. If the behavior follows the control module, then it's time to send that one in to the lovely folks at Lite-Trol for a little of their special attention.

What might be going on is that there's a problem with the circuit in that control module that detects when the 60Hz sinewave that is AC power crosses zero. SCR dimmers need to know when the zero-crossing happens in order to turn on at the right time, and the behavior can be similar to what you described when that stops working.
 

Shawn P

Member
Joined
Mar 11, 2019
Location
USA
Thanks for the information. It is an ENR rack. So I can try swapping both control modules from the one rack to the other and see if the problem follows?

IMG_2742j.jpg
IMG_2743j.jpg
 

microstar

Well-Known Member
Joined
Jan 19, 2014
Location
Lawton, OK
To help narrow things down.....the top control module of each rack controls dimmer slots 1-48, the second module controls dimmer slots 49-96.
Make a note of all the "rack number" thumbwheel settings before you do any swapping. You will need to change the settings if you swap modules between racks.
DO NOT touch the Viewpoint module (third module in the right-hand rack).
Looks like a lot of dust buildup. When you have modules out of the rack, take some canned air and blow them out, especially the grille at the left end where the airflow sensor is located.
DO NOT move modules with the power on and if you are at all hesitant about doing any of this, please seek qualified help and remember how much you are paying for this advice!
Steve Short at Lite-Trol is your friend... he knows ENR backwards and forwards.
 

Shawn P

Member
Joined
Mar 11, 2019
Location
USA
To help narrow things down.....the top control module of each rack controls dimmer slots 1-48, the second module controls dimmer slots 49-96.
Make a note of all the "rack number" thumbwheel settings before you do any swapping. You will need to change the settings if you swap modules between racks.
DO NOT touch the Viewpoint module (third module in the right-hand rack).
Looks like a lot of dust buildup. When you have modules out of the rack, take some canned air and blow them out, especially the grille at the left end where the airflow sensor is located.
DO NOT move modules with the power on and if you are at all hesitant about doing any of this, please seek qualified help and remember how much you are paying for this advice!
Steve Short at Lite-Trol is your friend... he knows ENR backwards and forwards.
Thank you, that's is very helpful. I am going to engage our school's electrical contractor to assist with this. I work strictly in an advisor role as the technical director for the space (my main job is System/Network Administration) so anything above 24 volts I don't like to touch.
 

EdSavoie

Well-Known Member
Joined
Oct 19, 2016
Location
Windsor, ON, Canada
I've run into a problem like this before with full size ENR racks. On the one I work with, the top brain on the rack gets cranky once in awhile and stops responding until you run upstairs and hit the controller reset button on the front of it.

Getting someone to kill all power to the rack and swapping the computers around will likely narrow down the problem pretty quickly assuming you've already unsuccessfully pushed reset
 

David Ashton

Well-Known Member
Joined
Sep 8, 2007
Location
perth W Australia
So - Colortran dimmers are pretty much like CD-80 dimmers, are pretty much like 1st gen Sensor racks with MPEs - SCR blocks controlled from a central brain, try swapping trays around in the rack (?) - from what you're describing I'd definitely look at the patch to make sure somehow a custom dimming curve didn't get selected when patching this range of outputs. Then I'd take a look at how neutrals were run to this bar. I'd almost be willing to bet that it's not neutral per circuit and you may have lost a neutral or two and now are experiencing the fun of networked circuits. Has this just recently become a problem or are you just now noticing it? Has anything been changed since you last did a show here when everything worked as expected?
My first check would be the neutrals on the bar.
 

ML.Rice

Member
Joined
Oct 19, 2017
Location
Lancaster, PA
If you are still having issues with this, Knight Sound and Lighting based in Ohio are a great resource for help with Colortran systems as well. They also have replacement dimmer modules for sale and will often rebate them if you send them your bad ones. They helped me through two 4-rack meltdowns and bought my old dimmers when we got to upgrade to Sensor racks.

My two cents: make sure the dimmers are clean; in your pictures they look really dusty. Our colortran ENR racks would get cranky if there was an errant dust bunny inside one. Get an upholstery crevice attachment for a vacuum and vacuum out all of the vents on the front of the control cards and then pull your dimmer cards out one by one and clean those with compressed air.
 

Shawn P

Member
Joined
Mar 11, 2019
Location
USA
Thanks everyone for your suggestions and ideas. After working with our facility’s electrician, we cut power to the rack and swapped cards. The problem did not follow the card, it went away completely! Now I have full dimming back to all of my circuits again. We also did some cleanup of the dust as suggested and will be replacing the battery in the Viewpoint card as well just for good measure. Luckily I have a good memory card and instructions for that.
As an IT person I know a reboot is always the first step, but most of my reboots don’t involve a 600 Amp switch! :eek:
 

microstar

Well-Known Member
Joined
Jan 19, 2014
Location
Lawton, OK
Thanks everyone for your suggestions and ideas. After working with our facility’s electrician, we cut power to the rack and swapped cards. The problem did not follow the card, it went away completely! Now I have full dimming back to all of my circuits again. We also did some cleanup of the dust as suggested and will be replacing the battery in the Viewpoint card as well just for good measure. Luckily I have a good memory card and instructions for that.
As an IT person I know a reboot is always the first step, but most of my reboots don’t involve a 600 Amp switch! :eek:
Glad you were able to revive it! In the future, as @EdSavoie mentioned, pressing the reset button on each control module would force a reboot without exercising the 600A disconnect. What probably happened was that the module's pc board contacts to the rack socket might have been a little tarnished or not making perfect contact and the process of removing and replacing them enabled a better connection. If you take them out again you might clean all the contacts in addition to vacuuming. Fairly common with the ENR's.
 

RonHebbard

Well-Known Member
Premium Member
Joined
Jun 12, 2004
Location
Waterdown, ON, CA
Glad you were able to revive it! In the future, as @EdSavoie mentioned, pressing the reset button on each control module would force a reboot without exercising the 600A disconnect. What probably happened was that the module's pc board contacts to the rack socket might have been a little tarnished or not making perfect contact and the process of removing and replacing them enabled a better connection. If you take them out again you might clean all the contacts in addition to vacuuming. Fairly common with the ENR's.
@microstar A soft, white, drafting eraser worked well for lightly burnishing the male contacts; unmating and remating several times usually took care of the females (female contacts that is) [Don't go there!]
Toodleoo!
Ron Hebbard
 
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