variac wiring

Lbc · Post by **Lbc** » Mon May 30, 2005 2:24 am

I m going to use the staco variacs in my studio and I have two questions.

1. from looking at their wiring diagrams it seems that you connect a hot and neutral from the power source and then the variable output goes to the light. Do I have this right? I want to put switches before the variacs for on/off control and am about to start the wiring for the lights.

2. What size wall box will the stacco 501 fit in. I remember seeing pictures of someone's studio with the boxes mounted but don't remember seeing any specs. on the boxes. I plan having 4 dimming zones ie 4 variacs. I assume that they don't fit in a regular wall box. And probably should be mounted in a metal box because of heat.

Thanks

Post by **Aaronw** » Wed Jun 01, 2005 1:58 am

I used a 6"x6"x4" box to mount mine in.

If you look at the bottom of the transformer where the connections are, you'll see the pin out.

eg: Input 50/60Hz 120V 1-2
Output 50/60Hz 120V 1-3

The one that is the same (1) in this case is Neutral and will be shared. Pin 2 would be the Hot leg input from the panel. Pin 3 would be the output to the light fixture.

That's how my variacs were labeled. I'm not sure about yours, but this should give you the general idea for wiring.

Post by **Aaronw** » Wed Jun 01, 2005 10:51 pm

I just pulled up a spec sheet on the 501. Looks like the inputs are 1-4 Outputs are 4-3

http://instrumentation-central.com/Stac ... /vt500.pdf

Lbc · Post by **Lbc** » Thu Jun 02, 2005 6:47 am

thanks I did the same

lunatic · Post by **lunatic** » Thu Aug 24, 2006 9:07 am

Aaron... what gauge wire did you use to run power to your variacs? Mine has a mx output of 5 amps. It would seem 12 gauge wire would be overkill. Also, did you solder or use the quick connects?

Peace,
Brad

Post by **Aaronw** » Thu Aug 24, 2006 10:55 am

I used 12 guage for all wiring in the studio. Granted, for lighting, you could probably use 14 AWG.

I ended up soldering about a 6-8" lead on each one, then used wire nuts to connect the in/out connections.

However, I had to drill out the hold a little larger. Some worked out perfect, however, I've managed to screw up 3 transformers accidently. From here on out I'm going to use connectors. (2 were messed up by drill, the other...well, let's just say I somehow mixed up the common and hot leads...DOAH!

) Shall we say I had a sparking good time!

Don't ask, it was one of those moments, long day, and didn't double check myself.

lunatic · Post by **lunatic** » Thu Aug 24, 2006 12:50 pm

Just got back from Home 'Despot.'

We have used 12 wire everywhere in the studio but for the power feeds to the variacs I'm going to step it down to 14 stranded. I bought quick connects too. So, we'll strip and tin the 14 gauge wire and then crimp to the quick connects.

Maybe I should take some photos and try and 'document' the process for future installers?

Peace,
Brad