---------- Forwarded message ----------
Date: Sat, 8 Mar 2008 08:52:13 -0800 (PST)
From: cpz@...
To: EntertainmentElectricity@yahoogroups.com
Subject: Re: [EntertainmentElectricity] Re: 120VAC over microphone cable?!?

In a flurry of recycled electrons, Steve Terry wrote:
[Charset ISO-8859-1 unsupported, filtering to ASCII...]
> --- In EntertainmentElectricity@yahoogroups.com, "Ken Porter"

>> Apparently the tech who came with the show wants to run 120VAC power,
>> at 1.1 amps over microphone cable (i.e. 3-pin XLR, typically about 20-
>> gauge wire) to run a small motor.

> If it's line voltage, and it's in a theatre,covered by NEC article
> 520, it needs to be run on an extra-hard-usage cable (see NEC table
> 400-5 for allowable Extra Hard usage types).

A few thoughts, as the coffee works it's magic:

There are some varieties of mic cable that would be fine with 1a, IIRC
Belden makes some 18g stuff with a rather heavy (read- almost forklift
proof) jacket. You probably don't have that. Past that, most flexible
mic cable is probably "unrated", anyway.

Art. 520 and it's friends in the 520's do cover theaters and temporary power.
There is a way to read individual pages on the NFPA web site for free.
You'll have to look there for further info.

-IF- the motor in question is part of a "power-limited" circuit using a
listed supply, and is part of a manufactured system (that's listed), it
might be OK. Plugging into the wall doesn't count :-).

It might fit in the catagory of a Class-1 remote control circuit, but
you still need at least 18g. Class-1 circuits can mix power and control
conductors in the same assembly.

I suppose that's a long winded way of saying "not in -my- house."

(FWIW, I might tolerate zip cord run out to something like this, but
I'd want to see everything first. Given the price of cheap-a$$ 16g
extensions, I'd rather they used some of those.)

z!


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