Design Zip Cord Basics

[Hugtrain]

Hello!

I've heard some things online about controlling a practical with zip cord. I'm having trouble finding resources online for using this and our library is currently updating its selection of theater-related books, so I'm turning to CB.

Could someone tell me how these three things connect and work safely (short of plugging wires straight into a socket)?
I feel like I'm missing some parts in between?

Please also let me know if there's another, perhaps better, way.

Thanks!

 

[cbrandt]

You're absolutely missing parts there, and they are some pretty basic ones. Have you had this conversation with your professor/teacher/technical director? This is high voltage electrical work that can cause a lot of safety issues if not done by someone qualified and experienced.

 

[Hugtrain]

You're absolutely missing parts there, and they are some pretty basic ones. Have you had this conversation with your professor/teacher/technical director? This is high voltage electrical work that can cause a lot of safety issues if not done by someone qualified and experienced.

I will be talking with other people, but I wanted to conduct some base-level research before I even begin to discuss it so I would have an idea of how it works.

 

[FMEng]

This is no different than building a lamp for your home, and there are plenty of Youtube videos on doing just that. After that, it's just a matter of plugging the lamp into a dimmer channel.

 

[Hugtrain]

This is no different than building a lamp for your home, and there are plenty of Youtube videos on doing just that. After that, it's just a matter of plugging the lamp into a dimmer channel.

Oh yeah, that makes sense

 

[jglodeklights]

Like FMEng said, this is the same as building a lamp for your home, but obviously you'll engage an adult before actually doing any of this. However, if you're planning on anything more than one or two lamps on the line, or are using bulbs/lamps drawing more than 100Watts each, you'll have even more learning to do. For example, the previous production we put up at my theater had thousands of bulbs integrated into various set pieces as chase lights in various wattages depending on the piece (and Voltages for that matter, but we won't really get into that for the moment). We needed to ensure the zip cord we used was the gauge rated for the amount of current being drawn and that the lamps selected were an appropriate Wattage so we didn't overload dimmers. You can also find some good tutorials on YT to get you up to speed on the basics of selection of wire gauge and calculating power draw.

 

[Hugtrain]

However, if you're planning on anything more than one or two lamps on the line, or are using bulbs/lamps drawing more than 100Watts each, you'll have even more learning to do.

Thanks so much, this is very helpful!

 

[derekleffew]

BTW, I can't tell whether the red and black wires are physically connected to one another, but whether they are or arn't, that ain't zip cord.

 

[Hugtrain]

BTW, I can't tell whether the red and black wires are physically connected to one another, but whether they are or arn't, that ain't zip cord.

Oh, I just looked up Zip cord and that showed up. I found some lamp wire just now at home depot, then a keyless lamp holder, and a plug. I think I understand now

 

[RickR]

There a minor issue with lamp cord in theaters. The National Electrical Code section on theaters has some rules to follow that limit lamp cord. (NFPA 70 520 Part V) I leave it to you as a learning opportunity to find and read that section for yourself, or with your teachers. "Hard usage" and "extra hard usage" have very specific meanings for wire types.

At the very least use lamp cord as little as possible!

 

[Hugtrain]

There a minor issue with lamp cord in theaters. The National Electrical Code section on theaters has some rules to follow that limit lamp cord. (NFPA 70 520 Part V) I leave it to you as a learning opportunity to find and read that section for yourself, or with your teachers. "Hard usage" and "extra hard usage" have very specific meanings for wire types.

At the very least use lamp cord as little as possible!

It has come to my attention as well that lamp cord is usually 18 gauge and our theater has 20 amp circuits which I believe requires 12 gauge

 

[avkid]

It has come to my attention as well that lamp cord is usually 18 gauge and our theater has 20 amp circuits which I believe requires 12 gauge

Conductor size is dictated by load, not by the size of the breaker.
(for load, not line feeding a breaker)

 

[Hugtrain]

Conductor size is dictated by load, not by the size of the breaker.
(for load, not line feeding a breaker)

Oh, it was my understanding that circuit breakers protected the wire from overheating and catching fire if there was too much draw on the line.

If that doesn't apply here, what wire would be safe to use? I was looking at 12/2 NM-B wire, is that appropriate?

 

[avkid]

Oh, it was my understanding that circuit breakers protected the wire from overheating and catching fire if there was too much draw on the line. If that doesn't apply here, what wire would be safe to use?

A breaker will generally not thermal out until quite a bit past it's load limit.
Do not rely on a breaker instead of proper load calculations.

What are you trying to connect?
You can use a Calculator to find out the ideal size of wire.
(fill in- cable, 120V, 1 phase ,copper )

 

[Hugtrain]

What are you trying to connect?
You can use a Calculator to find out the ideal size of wire.
(fill in- open air, 120V, 1 phase ,copper )

1.) A lightbulb or multiple in parallel

2.) That's strange. I used another calculator earlier and it said 12 gauge, but this is saying 6 gauge with the same parameters

 

[DuckJordan]

1.) A lightbulb or multiple in parallel

2.) That's strange. I used another calculator earlier and it said 12 gauge, but this is saying 6 gauge with the same parameters

how long of a run are you expecting?

 

[Hugtrain]

how long of a run are you expecting?

Most likely 25 to 50 feet

 

[DuckJordan]

Most likely 25 to 50 feet

Double check what you put in for amps, cause for you to need #6 you'd need to go 1000'

 

[avkid]

3 amps (6 60w lamps)
14 Awg
Max voltage drop at 50ft to 118.8V

 

[derekleffew]

I think you skipped a couple of steps there, Phil.
Care to show ALL your work?