House Light Issue

[derekleffew]

You used your own 200A disconnect for a 120K rig?

 

[JD]

Uncommon these days.
Very common back in the "pure par" rock days of the 70s & 80s. 200amp gives you enough to run 65k flat out. But unlike theater, the old rock shows are very transitory in nature, except for the flat out "full wash." I once (in the afternoon) threw everything up just to see how long it would take before my disconnect dropped. 22 minutes. Breakers trip on a curve. The greater the overload, the faster they trip. I can remember running plenty of 24k club shows where we were limited to a 50x2. (once even on a 30x2, but very cautiously!) Can't actually ever remember dropping a breaker during a show.

The other thing to keep in mind was it was very rare to actually find something larger than 200a, except on arena venues. Times change. The 80s now seam like the wild wild west!

The 200 was something I always carried with me so I had it on the truck (wanted something between me and "that".) When they put in a switch the next year, 200 is what they put in. If I remember right, we were there three summers.

btw: Here's a neat graph of circuit breaker trip curves :http://www.accontrols.com/acatalog/Typical Circuit Breaker Trip Curve.pdf
According to it, I should have only got 8 or 9 minutes! (333 amps per leg)

 

[MNicolai]

Uncommon these days.
Very common back in the "pure par" rock days of the 70s & 80s. 200amp gives you enough to run 65k flat out. But unlike theater, the old rock shows are very transitory in nature, except for the flat out "full wash." I once (in the afternoon) threw everything up just to see how long it would take before my disconnect dropped. 22 minutes. Breakers trip on a curve. The greater the overload, the faster they trip. I can remember running plenty of 24k club shows where we were limited to a 50x2. (once even on a 30x2, but very cautiously!) Can't actually ever remember dropping a breaker during a show.

The other thing to keep in mind was it was very rare to actually find something larger than 200a, except on arena venues. Times change. The 80s now seam like the wild wild west!

The 200 was something I always carried with me so I had it on the truck (wanted something between me and "that".) When they put in a switch the next year, 200 is what they put in. If I remember right, we were there three summers.

btw: Here's a neat graph of circuit breaker trip curves :http://www.accontrols.com/acatalog/Typical Circuit Breaker Trip Curve.pdf
According to it, I should have only got 8 or 9 minutes! (333 amps per leg)

I've got a $25k electrical upgrade going on right now and I know they intend on wiring to account for 125% of the rated load potential between the disconnect and the 25kw transformer.

There's at least some amount of headroom there. I don't know if that's typical code or if my electrical contractor is doing that for added safety.

Even in household circuits though, you can get away with running over a little bit on 20A so long as it's not a continuous draw.

 

[JD]

In any permanent installation, the code book rules. You want to have everything done to handle the maximum load. Lighting has changed a lot since the "wild wild west" days of the 80s. Modern touring (rock) shows use a high percentage of movers and intels, sometimes exclusively. For the most part, these fixtures are drawing their maximum current at all times, irrelevant of the board settings. Power systems have to be designed with that in mind and here again, the code book rules.

The 80's were an anomaly. Big hair, bigger lights. I think the Who topped the bill on show size in those days, traveling with 450k. The progression of show sizes from the 70s to the 80's looked a lot like a graph of current gas prices! Then Vari*lites came on the scene, and everything changed.