Wiring a Remote Indicator Light

[RecceDG]

Hey all,

My project to build a shed to house my air compressor is nearing completion and it is time to think about wiring.

I have a 240 breaker ready to pop in the panel (the shop has its own mains supply) and I've got a chunk of proper armoured cable to run from the panel to the compressor motor. The shed butts up against the garage wall, the intent is to either run the armoured cable right through both walls, or run conduit through the walls.

What I want to do is to wire a light bulb inside the shop that is ON whenever the compressor power circuit is energized (I will turn the compressor on and off with the breaker) so I can tell when the compressor is active.

So that probably looks like conduit out of the main panel, to a wiring box, and then conduit from the wiring box to the light bulb and a separate conduit through the wall into the shed. (or maybe armoured cable through the wall into the shed)

How is that bulb wired into a 240V circuit?

What's code for through the wall wiring?

Thanks.

 

[gungatim]

do a search, I posted a step by step a while ago on how to do this.

http://www.garagejournal.com/forum/showpost.php?p=4980241&postcount=31

 

[404]

If running low voltage is preferred, a global input voltage laptop power supply can be be put next to and powered by the compressor circuit, and then the low voltage output of the supply can light a low voltage bulb.

 

[sberry]

I am not a fan boy of this witohut some caution. I am sure I mentioned it in another thread but note that the problem it was trying to pro0tect against was from something already added to it that didn't come from the machine builder and they should take note as to what a simple indicator would do for marketing.
Any wire added to this must be above the short circuit rating of the primary circuit.

 

[sberry]

The net has brought a lot of secondary stuff to the air compressor. Very few of these schemes would have been found but for industrial a couple decades ago, Franz started a lot of it with a couple brainfarts he had. He recruited me from an ag forum to Hobart and that's how I ended up on forums. I had spent about a year in electric talk before that and got on good with a bunch or really grumpy old farts.
But anyway, I have an air system I love and adore in the sense that it would get immediate attn. if it went down and have backup. Its not critical but like the water we have become accustom to having it as a valuable utility on tap.
I had a bearing and cap issue in my 40 yr old main last winter/spring and might have changed oil in here sometime but it basically hasn't been off line for 10 yrs. I have taken to shutting off an old hose I have outside for 20 yrs lately, the breaker has taken care of any problem I couldnt pm I ever had and I take my chances a bit with some connected hose and a couple things are simply off with a ball valve until I really need it.
We do not have auto drain but some used copper tubing from ball valves on the bottom of tank, air comp threads are here all the time, on occasion such as today following a couple weeks of work I walk over and kick the valve open with my toe for 30 seconds.

 

[Brian_WK]

240v to 120V step down transformer in a enclosure with a fuse protecting the line side and the load side wiring. Then run the 120 to a 5watt LED light bulb.

Brian

 

[sberry]

If you want to shut in a comp the right way use a service ball valve shut when its full with no leaks between it and the comp and shut off the breaker. Do it as a habit, this would be a routine like a welding tank, we keep the leaks to a minimum but its a rare day I forget to close one.

 

[sberry]

240v to 120V step down transformer in a enclosure with a fuse protecting the line side and the load side wiring. Then run the 120 to a 5watt LED light bulb.

Brian

Yes, add all the protection, not that it cant be done but where its worth it and the extra is a kind of a judgment question. I can and don't is what I can say, at 25 would have thought a lot of these were the best ideas I have ever heard, at 55 and been at it a while I outright don't like a lot of them, are less than enthused about another 1/3 and could subdivide it again in to 1/3rds.

 

[homebuilt burner]

I am not an electrician. That said when we wired my father's shop a friend who IS an electrician solved this problem by wiring the starter for the compressor through a relay off of the light switch so when the lights are off the compressor cannot run. I am sure someone here can tell you how through the magic off electricity he did this. But BEST IDEA EVER.

 

[wyliesdiesels]

OP- what is the HP rating of your compressor?

And since the compressor is not in sight of the panel, u will need a disconnect.

I am not an electrician. That said when we wired my father's shop a friend who IS an electrician solved this problem by wiring the starter for the compressor through a relay off of the light switch so when the lights are off the compressor cannot run. I am sure someone here can tell you how through the magic off electricity he did this. But BEST IDEA EVER.

Thats easy. U wire it to one side of the coil on the compressor motor starter...