Design So what do you think.

[Pirlight]

So here's the problem.
I was working with a Church, they recently moved into a new building. I was not around for the install of any of the electrics, dimming, or Patch bay (A nightmare in and of itself.) Anyway I had finished the show and was turning it around for their regular services and ran into a few snags. When I plugged lights into certain channels they would not work. They were plugged in correctly, Plug is wired correctly, Lamp is good, patched correctly (both in the physical patch bay and in the light board) fuses on the dimmer were good, and there was power coming from the dimmer to that channel in the patch bay. I know I metered it, going up to the cat walks at the actual pug, nothing. by all accounts the outlet should have power, but it doesn't I am not able to physicaly trace these lines at all.
We had an event happen during the show that is relevent. We had an individual dimmer blow as in sparks fly the whole nine yards. There has to be a short somewhere in the line, or the dimmer. There was nothing plugged in and it would still throw sparks. These channels are in the same pack as the one that blew.
What am I missing?

 

[Footer]

If there is a hard patch, there should be a breaker somewhere in the building between the cable you plug into the dimmer and the circuit in the catwalk. I am going to assume that breaker is blown. If that breaker does not exist, your not code compliant anyway and someone needs to get in there and fix that. Do some digging. Who knows where that breaker panel is, but you have to find it.

 

[Pirlight]

I will do some digging but I am pretty sure there is no breaker between dimmer and catwalk. The Patch bay is not anywhere close to code. That has been a bone of contention between myself and whoever thought this was acceptable. I took one look at it and Told the TD to ask for his money back. You should never have to lock & tag just to freaking change the hard patch. (Please view attachment...sitting down) Correct me if I'm wrong but isn't that against Osha and quite a few other rules? I have voiced this concern many times to the apropreate people. Last I heard they were fussing with the install company.
This is what I know about the distrobution it goes in this order. power from grey fuse panels on the wall to Leprecon dimmers, fuses on those, "Patch box" on the side of stage then directly to catwalks. Tubing going up to various catwalks. They somehow got their certificate of occupancy.
I got word this week, that they were building a proper patch bay and the Install company was going to not charge for it. (aperantly that was part of the problem in the first place.)
As I said before I will do digging, Thank you very much for the Imput. It is frustrating to me when I know the answer is probably simple but Somehow miss the mark.

 

[JD]

Is that kindling wood the blocks are mounted to in that firebox? I would normally not even ask this, but any chance they used a common neutral and it's open circuit? Can't really guess at the gauge, but looks unlike #12.

The fact you are having failures this early on is not a good sign.

 

[Footer]

With that tangle of a patch who knows what could be wrong. That thing looks like a freakin 66 block that you would use in a telephone system.

You could tone out each line and figure out whats wrong after you disconnect the line. There could be a bad splice somewhere in the walls that burnt and opened the circuit. If that is the kind of work that is visible, I shutter to think what is in the walls.

 

[Pirlight]

He, he, he, You know I seriously would love to office space the stupid thing. And yes that is a piece of plywood on the back of that. (hence the comment about sitting down when viewing the photo) Oh it get's better... the strips that run up and down, yeah those are like the old office phone junction boxes.
I had not thought of that.(the common neutral) I do know it has a bus bar with common ground, so it probably would not be too far of a stretch say it's also common neutral. It is very hard to make heads or tails out of anything coming in or going out of the box because it is such a mess. It is a screwy setup...On the junction box you have 4 slots for neutral then four for the hot and it goes in that order on each bar. Each bar is a dimmer. going from right to left 4 dimmers 48 channels. Oh yes and when it goes up to the catwalk it splits so you have 2 channels 1 dimmer. So there is the possibility for a wiring error. The TD is now really annoyed with the Installers, because they have screwed up the lighting as much as they have. (To say annoyed would be putting it Very politely) I am trying to help them when I can, but I can only work so many Miracles.
thanks again for the Input.
April

 

[JD]

With that tangle of a patch who knows what could be wrong. That thing looks like a freakin 66 block that you would use in a telephone system.

Yea, first take was "Punch down blocks?" It looks more like a version of screw blocks like the Bucanan type. I wasn't sure if those "lumps" were crimp taps, but I think (on second view) they're more like wire nuts with tape on them.

Hey, maybe the best way to get this cleaned up is call in an inspector! Unless it will cost you the position. He could make the call that the work was unacceptable, and that could be used to get the installer to clean it up. Someone cut corners.

 

[aemeeich]

Oh it get's better... the strips that run up and down, yeah those are like the old office phone junction boxes.

April

Don't get me wrong, there are plenty of things wrong with that picture you posted, however, the "office phone junction boxes" are actually DIN rail mount terminal blocks. They are a very common and appropriate method of wire splicing. You can get sizes large enough to handle 4/0 AWG wire carrying 230 amps.

This is the setup my dad and I built in the HS gymatorium I work at.

Here's a link to a .pdf of one manufacturer's selection. The first 3 pages are what I'm talking about.
http://www.altechcorp.com/PDFS/New_Blocks/SCREW.pdf

 

[JD]

How's that song go? "One of these thing is not like the other.."

Spectacular workmanship! Yea, the modern replacement for the Bucanan system of stack-able terminals.

Ah... never seen that many wires pulled through a conduit before.....

 

[shiben]

How's that song go? "One of these thing is not like the other.."

Spectacular workmanship! Yea, the modern replacement for the Bucanan system of stack-able terminals.

Ah... never seen that many wires pulled through a conduit before.....

Then you have missed all the fun! Try getting 2 12 chan vinyl covered snakes and 2 12 chan rubber covered snakes (mic lines) out from one 1.5" conduit, along with a couple other large thick cables. Not sure how we eventually got them out, I feel like an engine lift was involved.

 

[derekleffew]

... Ah... never seen that many wires pulled through a conduit before. ...

Certainly never that many wires through that size conduit. For good reason. While I can't be certain from the picture, I'd want to direct the installer to the appropriate codes on pipe fill requirements.

Forty 12g current carrying conductors in a 2" conduit?

 

[JD]

Certainly never that many wires through that size conduit. For good reason. While I can't be certain from the picture, I'd want to direct the installer to the appropriate codes on pipe fill requirements.

Forty 12g current carrying conductors in a 2" conduit?

Steve Terry would know for sure, but there might be a special application when the pipe section is less than 12 inches in length as these appear to be.

 

[n1ist]

There's no derating requirement for nipples (less than 24" long), but they can only be filled to 60%.
/mike

 

[aemeeich]

Yeah, I kinda wondered about that as well, but the electrician was the one that did that part of the install, and I have no doubt that he knows his stuff, so I never gave it a second thought.

I remember his concerns about the fill for the conduit going out to the lighting positions since I was adding more circuits than were originally installed in 1954 when the school was built. We looked up the fill allowances and luckily the 19 wires needed were allowed to fit though each conduit so we didn't have to run new conduit to the existing lighting positions.

He did insist on using 10 gauge wire everywhere because of the potential voltage drop over the long runs when running close to the full 20A (even though I told him the most I would ever put on a single circuit would be a 1k scoop or maybe 2 750w Altman elips). Thankfully this was done before copper prices got so out of hand. I wish I would have bought a few additional spools of wire at the time because now I am wanting to add a few new circuits in some places, but the wire is going to be so expensive it hasn't happened yet.

 

[BrockTucker]

If there is a hard patch, there should be a breaker somewhere in the building between the cable you plug into the dimmer and the circuit in the catwalk. I am going to assume that breaker is blown. If that breaker does not exist, your not code compliant anyway and someone needs to get in there and fix that. Do some digging. Who knows where that breaker panel is, but you have to find it.

Not sure if I'm misreading this. A patchbay has to have a breaker between the pigtail that plugs into the dimmer and the pigtail that I plug my fixture into? I've never heard of this, but then again I've never seen a professionally built patchbay either.

 

[derekleffew]

Not sure if I'm misreading this. A patchbay has to have a breaker between the pigtail that plugs into the dimmer and the pigtail that I plug my fixture into? ...

Yup, see http://www.controlbooth.com/forums/lighting/18540-wiring-infrastructure.html#post169848.

 

[BrockTucker]

Darn, thought that was the one system I had gotten up to code.