Extension Cords in Theatre Lighting

[barefootbryan2335]

What is the rule on using extension cords for theatre? We used extension cords on stage for practicals and between the fixtures (conventional Source Fours, etc.) and the shoebox dimmers. The inspector told me we could not do that anymore. It seems to me the code does not clearly define what is portable and what is permanent. I have seen extensions being used in the larger theaters around town and I saw some in the grid on Broadway the last time I was there.

 

[zbang]

What code section is the inspector citing? (Extension cords are quite common in professional theater, OTOH I've seen some amateur theaters that should have been closed for egregious cluelessness in their wiring.)

 

[n1ist]

From Steve Terry over on Controlbooth:

--6.0 m (20') max length for SJ (junior hard service or hard usage) and derivatives in breakout assemblies. Must be protected from physical damage by being supported over its entire length by a pipe, truss, tower, scaffold, or other substantial support structure. There is no minimum height off the ground specified. Must connect a single multi-pole connector containing two or more circuits and multiple 2-pole, 3-wire connectors. Must be protected by an overcurrent protective device of not over 20A. Section 520.68(A)(4)

--1.0 m (3.3') max length for SJ and derivatives in adapters and twofers. No length limit on twofers using SO or derivatives. Section 520.69(C)

All other applications require extra hard usage (SO and derivatives). Section 520.68(A)(1).

 

[ggunn]

I went to a production by a local theatre company in a (partially) converted warehouse space a couple of years ago, and the play was about Nikola Tesla. The overhead space was a veritable rat's nest of orange extension cords powering lights as well as dangling spark gaps all over the "lighting grid" (warehouse roofing rafters) that they set to sparking at various times during the performance. I don't think anyone from the local fire marshal's office saw the play.