Three dimmers won't turn off

[Chris15]

I agree with Derek here. LOTO time... BUT, a student doing LOTO - that could raise questions me thinks... IF it is dangerous enough to need lock out tag out, then how is it safe for a student to be doing it? Oh wait, I forgot. We're talking about charc now aren't we... His school just worries us all so what's one more issue?

 

[icewolf08]

Well, there are a lot of things to respond to here...

First off, Charc may have done some questionable things in the past, but I think that he is more than capable to pull out a dimmer module and stick it in another place in the rack. I know that we preach safety, but as has been said, you have to try pretty hard to zap yourself when you are swapping dimmers. If you are at all concerned, have your TD supervise (since you need his keys anyway).

Next, Dereck, what is wrong with Sensor+ racks? I have 4, they work great, and really the only difference is the CEM, all the modules are exactly the same. Besides, can you even still get the original Sensor racks?

Lastly, cleaning. There are oil free compressors and air delivery service. There are many things that don't like to have oil in the air, but there are many tools that need either oil in the line or to be oiled regularly. So, many people/shops have clean air outlets and outlets with oil. Just use the right one and you should be fine. Be gentle, but the ETC guys who did our Dimmer turn on and walk through told us that gentle with the comp-air should be fine. That, and there is the interesting trick with the old ETC CEM where often the airflow sensor would get clogged, thus forcing the rack fans on full time and causing airflow warnings, which just required a quick hit with comp air to clean out the sensor.

You should be cleaning your racks out every 400 operational hours (that is 400 hours with at least one dimmer on in a rack). At least that is what the ETC guys told me. Even in a "dust free" environment, unless you actually have your dimmers in a clean room, you should be cleaning them.

And now back to your regularly scheduled program...

 

[JD]

That's one think I miss about my old analog EDI racks (memory lane here), you could hot swap dimmers in the middle of a show if the need arose. Funny thing there was, in 15 years I never got to do that as none of them failed. Shame they were analog and weighed a ton. Oh well.

As for compressed air, I used a 30 psi system with a filter and a portable tank. Since this was a road show, I usually cleaned them outside on the tailgate of the truck. About once every year. One note of caution: Look at how the components are mounted first. The EDI mods were pretty indestructible, but I've seen dimmer mods where parts are on long leads or in positions where even a 30 psi blast could damage the part or cause ring cracks on the pcb.

This being the 80s, the biggest accumulation annoyance was tars from cigarette smoke! You could smell it right on the mods!

Back on the subject of the dimmer failure, I find it interesting that 3 channels failed at the same time. Did they have anything in common?

 

[TimMiller]

depending on the age of the cd-80 it may have had a ramp card go out. But if its a newer one the processor does everything, it does not have a ramp card.

 

[derekleffew]

The instructions for removing/replacing a Sensor dimmer module are as follows (from the doc titled "SensorSP6_Port.pdf"):
Removing dimmer modules
To remove dimmer modules, open the door, then grasp the
center part of the face panel with both hands and pull.
To replace the module, insert it firmly until you feel it seat
securely. When the module is correctly seated, it should be
flush with the other dimmer modules.
Warning: Do not touch the AC power bus. If more than one
adjacent modules are removed, the AC bus is exposed.

Note that the document does not state, as it should, that the D20(AF) module's two circuit breakers should be switched OFF before removing. NOR is there any warning regarding removal/insertion while active.

As to the CEM/CEM+ debate, I WILL NOT buy/recommend/specify a Sensor+ rack/pack until the numeric keypad returns. I should not have to require a laptop to address a Road Rack, or "set" a dimmer @Level; nor have to remember non-intuitive CheckMark and LightBulb icons.

I place the CEM+ in the same category containing 1986's New Coke and 1958's Ford Edsel.

STEVETERRY, please provide the industry with a "CEM-Classic". Don't make me resume using L86s, and burning EEPROMs!

 

[Charc]

Alex and Tim,

Aren't you concerned about showering your modules in tiny droplets of condensation from your compressors? I would think canned air is a better solution.

Here's a spur of a question:

Does blowing/sucking out dust markedly improve dimmer life?

 

[icewolf08]

Alex and Tim,
Aren't you concerned about showering your modules in tiny droplets of condensation from your compressors? I would think canned air is a better solution.
Here's a spur of a question:
Does blowing/sucking out dust markedly improve dimmer life?

Not concerned so much about water, not here in UT where you barely need a towel after getting out of a pool. To keep a humidity level of over 30% in my small (600 sq-ft) apartment I need to run 10+ gallons of water in my humidifier a day. Canned air can have condensation as well, so no real benefit.

Cleaning your dimmers improves performance, helps prevent overheating, reduces risk of fire, and yes, can keep your dimmers working longer for all of the above reasons.

 

[Chris15]

Off the top of my head, it's the compression process that causes condensation, so it is irrelevant whether the air comes from a compressor or from a can. And canned air is rather expensive...

Dislodging dust - yes, very much it improves things. Dust acts like a blanket. In Summer, when it's hot and say you've been exercising, you don't want a blanket permanently attached now do you? The same general theory applies to electronics. If they are covered in dust, grease and grime, then there is a somewhat substantial thermal inefficiency. Basically they can't dissipate the heat like they were designed to. If heat can't be dissipated, it builds up. Heat builds up and starts causing failures of various bits and pieces as well as placing more load on the cooling system, which, half the time, is also full of dust and so it works a bit like an artery with cholesterol lined walls, it can't pass as much air through and so the heatsinks which are relying on this forced air movement find they aren't getting the rated volume of air movement and so don't dissipate heat properly and will either trigger over temperature alarms or see above statements on not dissipating heat properly. Besides, fan grills which are covered in dust are a really good sign that you don't really care about your gear enough to keep it clean and I HATE the sound of a clogged fan grill when the fan is running. Yes, you can hear the difference, the fan sound like it's struggling because funnily enough it is...

While I was writing this, Alex posted, with what is essentially the gist of what I'm saying. I just used more words...

 

[TimMiller]

I have a air filter in line to filter out any water. Also, a few little water droplets never hurt anything , as long as its dry before reinstalling into the rack. I have done a few out door shows where our dimmer rack has gone for good little swim. After drying out with towels and hair dryer, fuctions just as good as new .

 

[gafftaper]

I clean my dimmers by dipping them in a 5 gallon bucket of Van's VSSD/MEK ULTRA Cleaner. They'll be shiny and I guarantee you'll never have a problem with the dimmers turning on again.

 

[icewolf08]

*nerdy accent*
i water cool mine

That is a lousy joke, there are fixtures, and most probably dimmers that use liquid cooling. Ever seen the lamps they use for IMAX projectors? Those have liquid cooling within the lamp. So while you may think it a funny joke, it is in fact a reality.

 

[derekleffew]

Shall I mention the Vari*Lite VL5 "Liquid Lens"? I'd better not. Nevermind. You didn't hear that from me.

 

[STEVETERRY]

The instructions for removing/replacing a Sensor dimmer module are as follows (from the doc titled "SensorSP6_Port.pdf"):
Removing dimmer modules
To remove dimmer modules, open the door, then grasp the
center part of the face panel with both hands and pull.
To replace the module, insert it firmly until you feel it seat
securely. When the module is correctly seated, it should be
flush with the other dimmer modules.
Warning: Do not touch the AC power bus. If more than one
adjacent modules are removed, the AC bus is exposed.
Note that the document does not state, as it should, that the D20(AF) module's two circuit breakers should be switched OFF before removing. NOR is there any warning regarding removal/insertion while active.
As to the CEM/CEM+ debate, I WILL NOT buy/recommend/specify a Sensor+ rack/pack until the numeric keypad returns. I should not have to require a laptop to address a Road Rack, or "set" a dimmer @Level; nor have to remember non-intuitive CheckMark and LightBulb icons.
I place the CEM+ in the same category containing 1986's New Coke and 1958's Ford Edsel.
STEVETERRY, please provide the industry with a "CEM-Classic". Don't make me resume using L86s, and burning EEPROMs!

The UL listing is not specific on this issue. But why would you hot swap? I'd warrant it would not even save you 100 ms to turn off the breakers and then re-energize them when the module is seated. Do it that way--it's just prudent for high powered electrical gear.

As to the CEM+ user interface, I feel your pain and we are working on a solution you will love.

ST

 

[icewolf08]

As to the CEM+ user interface, I feel your pain and we are working on a solution you will love.
ST

But is it going to cost me to upgrade to your new solution?

 

[STEVETERRY]

But is it going to cost me to upgrade to your new solution?

Whatever answer I give, I can't win!

Let's wait for the solution, and then we can have that discussion!

ST

 

[derekleffew]

...As to the CEM+ user interface, I feel your pain and we are working on a solution you will love.

Do I get a prize if the name chosen for the new product is "ETC CEM++™ "?

 

[STEVETERRY]

Do I get a prize if the name chosen for the new product is "ETC CEM++™ "?

We're way ahead of you....

ST

 

[derekleffew]

We're way ahead of you....

ST

I call shenanigans, as you had a head start!

Back to topic. Charc tells me he is going again to his facilities people armed with more ammunition from this thread. He also has the Strand Lighting part# required if failed SSRs are indeed the issue with his dimmers 99/100 and 109

 

[Charc]

I call shenanigans, as you had a head start!
Back to topic. Charc tells me he is going again to his facilities people armed with more ammunition from this thread. He also has the Strand Lighting part# required if failed SSRs are indeed the issue with his dimmers 99/100 and 109

Yep, 6th and 7th periods. Meeting with in-house electrician during that time at some point. Also going to run a couple other issues by him, and ask him to bring his DMM for a start. (I need to get new batteries for mine, and the weather outside is frightful!

 

[TimMiller]

Every venue i go into i make sure i become good friends with the electricians. You never know when you may need their help.