Electrical questions (lack of neutrals, what other things should be pulled)?

[JLNorthGA]

Turns out that our electrical system did not have an adequate number of neutrals for the circuits. So that is now going to be addressed - I'll see a quote tomorrow.

While they are up there, what else should I have them do? They are basically adding another cable to each raceway above the stage. They are going to add neutrals. I figure that as long as they are up there (and we have the lift), we might as well plan for the future.

With that in mind, what should I consider? Do I need to add any other cable? Possibly something to control LED lights or something?

 

[xander]

If you're up there already and running copper, I'd run some non-dim power: 120v and 208v if you ever use that. I'd run CAT6 as well. There is no such thing as too many data outputs. Even if you don't have the opto or means to use it yet, that can come in the future and having the cable already run will facilitate that upgrade.

-Tim

 

[Wood4321]

I agree with Tim,
I would run at least a 4 circuits of Edison 120 un-dimmed power.
I also would appreciate a few 208 circuits, once again as Tim said, assuming you ever use movers that require 208.
And Cat 6 or at the very least a DMX run or 2.

 

[JLNorthGA]

I agree with Tim,
I would run at least a 4 circuits of Edison 120 un-dimmed power.
I also would appreciate a few 208 circuits, once again as Tim said, assuming you ever use movers that require 208.
And Cat 6 or at the very least a DMX run or 2.

DMX I understand. I already have 120 V power (1 circuit per bar, possibly 2) - I can add another without too much difficulty. I don't know about 208. This is coming off of a 3 phase panel.

Why Cat 6 - just for computer control?

 

[techieman33]

I would add at least 4 20amp edison circuits, 2 5 pin dmx lines, and a cat 6 line.

 

[JD]

If the raceways use terminal strips, have them go right down the strip and make sure all the screws are tight. Those things have a way of loosing up over the years.

 

[SoundTom]

Why Cat 6 - just for computer control?

Cat 6 can do just about anything data based. I know my venue uses it to control our LEDs. IMHO, cat 5 or 6 is generally good to put up if you plan on upgrading in the near future.

 

[chausman]

Why Cat 6 - just for computer control?

Cat6 for DMX over Ethernet. You can rent or buy nodes from almost all console manufactures, so you can run LEDs/Movers/or other things that require DMX without having to run a line from the grid or from the deck.

Cat 6 can do just about anything data based. I know my venue uses it to control our LEDs. IMHO, cat 5 or 6 is generally good to put up if you plan on upgrading in the near future.

Cat6 if you have the choice. Since this is for "future proofing", Cat 6 should be more flexible (as in more protocols, not physically).

 

[MPowers]

DMX I understand. I already have 120 V power (1 circuit per bar, possibly 2) - I can add another without too much difficulty. I don't know about 208. This is coming off of a 3 phase panel.

208vac is what you get by tapping across any two legs of a 120vac per leg 3 phase system. You don't get 240 because the phases are 120 degrees apart, not 180.

 

[Repeater]

I don't know about 208. This is coming off of a 3 phase panel.

Between any two of the three phases will be 208V, assuming that this is a 120/208V 3 phase panel, which it probably is...

 

[museav]

Perhaps a bit more to the practical aspects but it seems the focus might need to be on 1) any other code compliance issues that need to be addressed and 2) what can legally fit and/or be run in the existing raceway/conduit. For example, it might be nice to have CAT6 but it may not be legal to run it in the same conduit or undivided raceway with power, which could affect the practicality of adding it, at least as part of this work. Similar for adding more power, perhaps a good idea if the existing service, distribution, dimming and raceway support what you want to add but maybe not as viable an idea if they don't.

 

[rsmentele]

Do you also already have dedicated work light channels? If not, might be worth it...

 

[tjrobb]

Re: Low voltage in raceways.
This is a no-go for places that follow the NEC. If the mains faults into the low voltage side things could get ugly.

 

[JLNorthGA]

Got the quote, ain't gonna happen

Plan B . I'll have to find another way to do this. They are talking about completely rewiring the cables and conduits that lead to the raceways. I know I need neutrals, but not at that price - I'm thinking someone wants a boat next summer or something.

 

[mstaylor]

Re: Got the quote, ain't gonna happen

Plan B . I'll have to find another way to do this. They are talking about completely rewiring the cables and conduits that lead to the raceways. I know I need neutrals, but not at that price - I'm thinking someone wants a boat next summer or something.

The idea is probably they think it will be too hard a pull so they want to pull it all out and start over. I would suggest they pull one wire and use it to pull in the new conductors. It may not work, can't tell without seeing it.

 

[venuetech]

Re: Got the quote, ain't gonna happen

when was this originally wired? was it up to code at that time? Has some event triggered this review of the wiring? are you currently bringing other code issues in the building up to date?
I worked in a theatre that was renovated in 1986 with new CD-80 racks installed. They wired them so each circuit (dimmer) phase "shared" a neutral. (three dimmers, one neutral) from my understanding, that met code at the time the work was done. I think the code changed at a later date.
I recall that the electrical contractor had underbid the job big-time and was looking to cut costs at every corner.
I had 192 dimmers If the contractor was consistent he only ran 64 neutral wires for the dimmer install. a very scary thought at this point in time.

 

[museav]

Re: Got the quote, ain't gonna happen

The idea is probably they think it will be too hard a pull so they want to pull it all out and start over. I would suggest they pull one wire and use it to pull in the new conductors. It may not work, can't tell without seeing it.

It could be a matter of the labor involved but NEC specifies maximum allowable conduit fill so it could also be a matter of any changes or additions exceeding the allowable fill. I do agree that all of us are simply second guessing based on the little we know about the situation.

Tom brings up a good point that sometimes changes require making anything touched compliant with the latest applicable code. I have seen numerous examples where what was initially viewed as a seemingly simple and inexpensive changes turned out to be much more complex and expensive because the changes planned required also addressing any related changes in code.

 

[mstaylor]

Re: Got the quote, ain't gonna happen

It could be a matter of the labor involved but NEC specifies maximum allowable conduit fill so it could also be a matter of any changes or additions exceeding the allowable fill. I do agree that all of us are simply second guessing based on the little we know about the situation.

Tom brings up a good point that sometimes changes require making anything touched compliant with the latest applicable code. I have seen numerous examples where what was initially viewed as a seemingly simple and inexpensive changes turned out to be much more complex and expensive because the changes planned required also addressing any related changes in code.

I agree, it could also be something along the lines of there being aluminum and switching to copper allows smaller wire to allow more conductors. Or they need t6o be split to get the nuetrals in the same conduit with the hots, then running a second conduit. Really many, many variables.

 

[JLNorthGA]

Re: Got the quote, ain't gonna happen

when was this originally wired? was it up to code at that time? Has some event triggered this review of the wiring? are you currently bringing other code issues in the building up to date?
I worked in a theatre that was renovated in 1986 with new CD-80 racks installed. They wired them so each circuit (dimmer) phase "shared" a neutral. (three dimmers, one neutral) from my understanding, that met code at the time the work was done. I think the code changed at a later date.
I recall that the electrical contractor had underbid the job big-time and was looking to cut costs at every corner.
I had 192 dimmers If the contractor was consistent he only ran 64 neutral wires for the dimmer install. a very scary thought at this point in time.

The raceways above the stage have a 26/12 gauge cable and several rather large neutrals cables (6 gauge). ETC would prefer that each circuit have its own neutral (understandable). The building was built in the early 1980s in rural far Western NC. So when they split the 3-phase, they shared neutrals.

What I'm tempted to do is have them use the existing cables to the raceways and "cut" the number of circuits. They can use the existing neutrals and some of the "hot" wires as neutrals. That way I would have less circuits available - say 8-9 per lighting batten.

That way they wouldn't have to run new cable, conduit and wire. Less time, less materials = less money. Sort of defer the problem to when we have more money.

That way I'd have a warrantied system - albeit with less circuits. But how many circuits do you really need above a stage? This way, I'd have 16-18 circuits. I figure I can live with that.

 

[chausman]

But how many circuits do you really need above a stage? This way, I'd have 16-18 circuits. I figure I can live with that.

If you can, great. I know my school has 12 circuits for the Cyc alone, as well as two more rows of x-rays that is always in the air, plus whatever we need to add for the show. You may be able to only have ~16 circuits, but I can almost garuntee you'll be kicking yourself later, when you have a show where you need more, or have to go through this all again.

My $.02