Any home electricians on here?

[Greg L.]

While chasing my tail again today I realized that I'm not quite sure what size breaker and wire I should get for the 220V 23A motor on my compressor. I get down to Home Depot and I get this "deer in the headlights" look looking at all the breakers and wire and plugs...

My biggest thing is that I don't know what size breaker to use with this 23a motor. I think the smaller 220v 15a compressors can get by with a 20a breaker and service wire but I can't seem to be able to find out what the 220v 23a compressors use. I'm thinking that a 30a breaker will do the trick but I'm not sure. If a 30a breaker will do then I should be okay with 10-3 wire but if I need a 40a breaker then I'm looking at 8-3 wire. The service cable from the sub panel to the compressor will be about 20' long.

So what do you think I need? ...30a breaker with 10-3 cable or 40a breaker with 8-3 cable?

Thanks again guys.

[Dennis C.]

Any home electricians on here?

10/3 wire w/ground. 30 Amp breaker... Should be safe and good to blow...

[Greg L.]

Re: Any home electricians on here?

Thanks Dennis.

A friend of mine suggested I use the 8-3 cable and 40a breaker but I think that is over kill... His theory is that the start up current will be much higher than 30a. That might be true but I think that the breakers are designed to handle this initial surge and only trip if the over current is for a prolonged period so I think his theory is flawed somewhat.

I was thinking that a 30a breaker would work based on my "theory". That theory being that 15amps is 75% of a 20a breaker and 23amps is 76% of a 30a breaker.

Anyways thanks for confirming that the 30a breaker and 10/3 wire will do the trick! I'm off to Home Depot in the morning!

[David E.]

Re: Any home electricians on here?

It will work like a charm.

[David S.]

Re: Any home electricians on here?

Greg
What you will need is one 30 amp 2 pole C/B
Save your money you will not need 3 wire cable.
You will need # 10 -2 wire cable.
Two wire cable has 2 insulated conductors and one non insulated conductor
Two insulated wires go to the 30 amp C/B & the bare copper conductor goes to the ground bar.

[Dennis C.]

Any home electricians on here?

David...
I agree, what you prescribe will work. But is it up to NEC? The differences are simply a code/safety issue, not one of performance. DC

[David S.]

Re: Any home electricians on here?

Dennis I see no code safety issue. Two insulated wires for the two 220 volt wires and one bare conductor for the equipment ground. The 220 volt receptacle will have only three screws for wire termination. A neutral conductor is not necessary unless a 110/220 volt connection is required.

[Dennis C.]

Any home electricians on here?

David, I will defer to your opinion, though requirements may vary from state to state, county to county.
In either case, our friend will be able to safely use his new high performance compressor with no electrical worries...

[David S.]

Re: Any home electricians on here?

I agree Dennis safety is always first.
Dave

[Greg L.]

Re: Any home electricians on here?

Thanks again guys.

I kinda thought that the 10/2 wire would work but I think the code up here would call for 10/3 so that is what I picked up yesterday.

[Mike M.]

Re: Any home electricians on here?

Always a good idea to stick with copper as well.
HaND

[Charles M.]

Re: Any home electricians on here?

Greg, I am a licensed electrician from Mass. (now in Fla.) Connect your compressor using the black, red, and bare wire for ground if you use 10/3. There will not be any connection for the white wire. A 30 amp 2pole breaker is what you need as previosly mentioned.
Chuck M.