stage wiring
stage wiring
Thank you and everyone else on this board for your input on this situation.
Scenery Driver explained the way that sets are rigged in a lot more detail than I did.
My main concern about this method was the fact that:
Example: Top of receptacle (panel A, blue phase) controlled by dimmer board.
Bottom half of receptacle (panel B, red phase) controlled by circuit breaker.
Now, we have an antique two wire table lamp plugged into the top of receptacle. (a prop for part of the scene)
In the bottom half of the receptacle, we have a "studio light" (often, we need more light for filming)
These two lights are sometimes in very close proximity to each other; within arms reach.
If there happened to be a fault in either of these fixtures and someone was touching both units at the same time, would that be... a bad day?
Also: a couple of replies mentioned; ...must be on the same phase. Another: must be on a different phase.
Which one is correct?
We now use a lot of LED studio lights combined with our existing incandescent lights and every now and then, we have a some power problems (flickering lights and malfunctions) a couple of times when they were plugged into a set wall outlet.
We then test them on floor power and the units are fine?
Thanks for your time.
I work in the Entertainment industry, and I can tell you this is common practice. It's often a necessity, as onstage lamps (practicals) must be controlled with the rest of the stage lighting. The bottom half of the receptacle is then used to operate other stage practicals that require constant power (record player, stereo, etc...)
Is it safe? Yes. Is it to code? Technically no, but it really doesn't matter. It's not permanently installed, and it's accessible only to trained, qualified stage electricians and stagehands that understand what's going on. We typically wire out of the outlet box with two 6' SO cable whips. The dimmed half of the receptacle is connected to the whip with a 20A stage pin plug, and the non-dim side is connected to an L5-20 Twist-Lok plug (prevented inadvertent swapping of dimmed and non-dimmed power to the receptacle). The local plugs serve as the "local disconnecting means" if you need to service the receptacle.
Everything backstage is connected with SO cable, so it's not "code" anyway. That's just the way it is in the Entertainment industry. No one is running conduit on a set that is only up for a few weeks.
I used to live and work in Chicago - possibly the most stringent jurisdiction in the country when it comes to electrical and fire safety in theater (for obvious reasons). The Fire Marshal was perfectly fine with "temporary" wiring methods, so long as things like wire gauge and grounding were up to snuff. The NEC can't always account for strange occurrences, and I can tell you that Entertainment can be the strangest of animals; it's amazing what designers will dream up.
SceneryDriver