Leaving Dimmers on always? Controller?

[variable]

I run a small show that's been going for about 40 years 5-6 days a week. We recently lost our venerable AVAB 12x2.4k stack and I'm replacing them with ETC Smartpack wall and rackmount units. The AVABs were always on, 24/7 from 1982 until last week, when the last one melted a main.

I called ETC tech support and asked their opinion on the matter, and kind of got a yes and no response, so I thought I'd ask the professionals here: Should I continue to leave the Smartpacks on 24/7, or should I power them down at the end of every night? I also have the same question with my controller. I've worked in houses that did both, left the controller running for a decade or longer, or powered it down every night. What are the benefits/tradeoffs of shutting down your system every night aside from a slight electricity savings?

If this topic has been discussed here previously I'd appreciate a pointer; I tried many different searches and couldn't come up with any discussion on the topic. Thanks for your thoughts.

 

[FMEng]

The biggest thing you can do to extend the life of your equipment is to keep it cool. That means giving it a cool, clean environment, providing free air space around it, making sure its fans are operational, and keeping the internals dust free.

Stay with the wall mount units instead of the rack mount units. The latter have to be designed to be compact and rugged, which usually means thermal compromises are made.

 

[Les]

I would say that as long as the packs (or racks) go dormant during periods of non-use (even - or especially) without fans running, leaving them on 24/7 shouldn't be an issue.

 

[variable]

I would say that as long as the packs (or racks) go dormant during periods of non-use (even - or especially) without fans running, leaving them on 24/7 shouldn't be an issue.

Would you recommend the same for the console? We're currently running an ETC Element.

 

[variable]

Stay with the wall mount units instead of the rack mount units. The latter have to be designed to be compact and rugged, which usually means thermal compromises are made.

Heh, the last way I would describe a rack mount Smartpack is rugged, but I take your meaning. Unfortunately I did not have the down time to wire our circuits into new wall mount units, so a 1 for 1 swap of the AVABs was my only option. Fortunately the dimmer closet is also the main air intake for the house, so there's a constant wash of cool San Francisco air right over the rack. It kept a stack of AVABs alive for over 30 years, so I'm optimistic about the smartpacks, which hardly even register heat compared to the old units.

 

[Les]

Would you recommend the same for the console? We're currently running an ETC Element.

I would recommend powering the console down every night.

 

[DrPinto]

Personally, I'm in the "shut it off" camp when it comes to dimmers. My reasoning is:

1. It's just a waste of electricity to keep something powered up that you're not using.

2. The longer the fans run, the more dust gets into your equipment and the more often you have to clean equipment and filters.

3. If equipment is on at all time, it's more susceptible to power surges during storms.

4. It's safer to hang and circuit instruments with the dimmers off. If the board is off but dimmers are on, there's still voltage at the plugs. The last thing I need is to get shocked by a defective instrument while on a ladder.

 

[variable]

I would recommend powering the console down every night.

But the joys of popping open iRFR on your way into the theatre and starting the warmup sequence are sorely limited by having to scale the lighting tower to power up the board

 

[variable]

Personally, I'm in the "shut it off" camp when it comes to dimmers. My reasoning is:

1. It's just a waste of electricity to keep something powered up that you're not using.

2. The longer the fans run, the more dust gets into your equipment and the more often you have to clean equipment and filters.

3. If equipment is on at all time, it's more susceptible to power surges during storms.

4. It's safer to hang and circuit instruments with the dimmers off. If the board is off but dimmers are on, there's still voltage at the plugs. The last thing I need is to get shocked by a defective instrument while on a ladder.

I'll have to see how much power draw you get for an idle smartpack. It was pretty nominal for the AVABs. But your last point is pretty well taken. If I kill the dimmers for a hang, why leave them on other times when they're not in use?

 

[derekleffew]

From http://www.controlbooth.com/threads/do-strand-century-dimmer-leak.33594/ :

Lastly, do know that most facilities outside the Americas turn their dimmersystem off at night. There are various reasons for this but the primary one is safety.

See also http://www.controlbooth.com/threads/what-do-you-leave-on-24-7.24027/ .

 

[FMEng]

If you do turn them off, the question becomes how to do that. Circuit breakers are not intended to be used as a switch, and may fail after many operations. An electrician could install a disconnect switch.

 

[JD]

If you do turn them off, the question becomes how to do that. Circuit breakers are not intended to be used as a switch, and may fail after many operations. An electrician could install a disconnect switch.

This is probably the only reason to keep them on. In every other aspect, the cons outweigh the pros. Safety, power surges, aging (especially fans), power consumption (especially if lamps are set to idle) all weigh against the 24/7 approach. But, how do you turn them off? Not with a breaker! Disconnect knife switch? If you have one, but installed systems rarely do.
On the brighter side, as we all know, if a system is going to die it usually does so as it powers up

 

[BillConnerFASTC]

If the dimmers are in a space that may get damp - either unheated and cold condensing or humid climate and ac being turned way back or off - I'd leave the dimmers powered. If in a 24/365 conditioned space, wouldn't bother me to de-power.

Someone looked at a relay to do this remotey and conveniently and found with the quiescent power of 3 or 4 Sensor racks, the cost of the gear was never paid back.

 

[SteveB]

If the dimmers are in a space that may get damp - either unheated and cold condensing or humid climate and ac being turned way back or off - I'd leave the dimmers powered. If in a 24/365 conditioned space, wouldn't bother me to de-power.

Someone looked at a relay to do this remotey and conveniently and found with the quiescent power of 3 or 4 Sensor racks, the cost of the gear was never paid back.

Yup, we had a consultant wanted to do this on our new system 12 years ago. I think the CEM+ with fan pulled something like 7 watts or so, I recall checking with ETC. We would have never recovered the cost of the relays.

ETC, if memory serves, has no issues with racks being powered 24/7 and I do not power down, ever.

 

[variable]

Yup, we had a consultant wanted to do this on our new system 12 years ago. I think the CEM+ with fan pulled something like 7 watts or so, I recall checking with ETC. We would have never recovered the cost of the relays.

ETC, if memory serves, has no issues with racks being powered 24/7 and I do not power down, ever.

Yeah, I'm already fighting that battle in a house that has used breakers to turn off the backstage work lights for decades. I'm not going to start using my 100+Amp breakers as off switches. It simply doesn't seem worth it in the long run--and no, when I talked to ETC they said they didn't have a strong opinion either way, which I took as an endorsement to leave them on if I so chose.

 

[variable]

If the dimmers are in a space that may get damp - either unheated and cold condensing or humid climate and ac being turned way back or off - I'd leave the dimmers powered. If in a 24/365 conditioned space, wouldn't bother me to de-power.

Someone looked at a relay to do this remotey and conveniently and found with the quiescent power of 3 or 4 Sensor racks, the cost of the gear was never paid back.

That's a real interesting point. The vent cooling the dimmers is direct from the outside, barely a dust filter between the city air and the dimmer fans. Wwe smell anyone smoking out front, idling bus exhaust, etc. Today the whole house smells like barbecue as there's a street fair outside. That's a pretty good argument for leaving them on

 

[SteveB]

That's a real interesting point. The vent cooling the dimmers is direct from the outside, barely a dust filter between the city air and the dimmer fans. Wwe smell anyone smoking out front, idling bus exhaust, etc. Today the whole house smells like barbecue as there's a street fair outside. That's a pretty good argument for leaving them on

On a Sensor, the top mounted fan doesn't run unless DMX is asking a dimmer to dim or provide power, relay to function, etc.., thus if the fan isn't running, there's no airflow thru the door mounted filters. Thus no real issues with dust.

Plus the racks are usually (but not always) in a room of some sort,

 

[DrPinto]

If you do turn them off, the question becomes how to do that. Circuit breakers are not intended to be used as a switch, and may fail after many operations. An electrician could install a disconnect switch.

Circuit breakers certainly can be used as switches. I've seen this in several large industrial buildings in my travels. Yes, circuit breakers will fail evidently, just as switches and relays will too. I would have no trouble with using a breaker as a switch with a few exceptions. One is with 277 volt florescent and HID lighting (I believe special breakers are required).

Another exception is with Federal Pacific Electric (FPE) Stab-Lok breakers. There are serious safety issues with these breakers. I wouldn't touch them at all. These are bad news. If you come across these, the entire panel should be replaced.

I would much rather replace a breaker that fails after many years than hang instruments with power at the plugs. Try explaining to someone who gets accidentally shocked that the power was left on because you didn't want to wear out the breaker.

FYI...FPE Stab-Loc info...

http://inspectapedia.com/fpe/FPE_Stab_Lok_Hazards.php

 

[Les]

I would much rather replace a breaker that fails after many years than hang instruments with power at the plugs. Try explaining to someone who gets accidentally shocked that the power was left on because you didn't want to wear out the breaker.

Can someone please give an educated guess or anecdotal evidence of how much power is present at the raceway when the dimmers are at zero, because I honestly have no idea.

I have never been concerned about it in the past and honestly, I continue to not be concerned about it. Does one power down the dimmer rack before disconnecting an instrument in order to change its lamp? I highly doubt it. Is it (arguably) more hazardous to go mucking around in some electrical room? Possibly.
I also don't know anyone who powers down the branch circuit before plugging in some small appliance in their home.

If they're touching conductors while connecting instruments, that's on them and one should never assume the power is off, thus it's a bad thing to become complacent about. If worried about a faulty instrument, well there's about as much danger present during focus while the lights are hot.

 

[variable]

Can someone please give an educated guess or anecdotal evidence of how much power is present at the raceway when the dimmers are at zero, because I honestly have no idea.

I have never been concerned about it in the past and honestly, I continue to not be concerned about it. Does one power down the dimmer rack before disconnecting an instrument in order to change its lamp? I highly doubt it. Is it (arguably) more hazardous to go mucking around in some electrical room? Possibly.
I also don't know anyone who powers down the branch circuit before plugging in some small appliance in their home.

To your first question I can definitely tell you that our old AVABs definitely had current to the plugs, though it was very little. To your second, while I certainly don't ask anyone to power down the dimmers to service a single instrument, I'd certainly turn it off for any significant work, like re-hanging the whole grid. I'm rehanging a single electric on Wednesday, and I plan on throwing the breaker on the dimmer pack and taping it over while we work. Why take the chance of arc welding a safety cable caught in a 2PG plug while you're patching a few dozen instruments on a ladder when you could just turn the dimmer off? That happened to me last year while I was moving instruments to make room. A new safety cable slipped and fell right between the plugs just as they made contact. Freak accident? Yes, but I was on a ladder on a balcony and the shower of sparks left me blind for about 30 seconds and I got a face full of sparks while I held on waiting for the breaker to trip. That was just a single patch. I can't count the number of times I've gone up to service an instrument to find an old Union stage pin plug with insufficient strain relief and bare or loose wire coming out the back.