got my new compressor today.... house electric gurus question

old_blue

15 Year Member
Nov 3, 2003
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First off I love it. 60 gallon 3.5 hp 12.8 scfm at 43 psi and 12 scfm at 90 psi.

I already had my garage plumbed for it. Question though. It says it is a 15 amp compressor that uses a 30 amp breaker. I assume it is because it may spike higher that 15 amp when running hard or during startup. After talking with the home depot guy for a few minutes he suggested a 20 amp plug (12 ga. pigtail wiring) and a 20 amp recepticle outlet. It is all 8 gauge wiring from a dual pull 30 amp breaker to the plug. I put 8 gauge as I was thinking I would run a welder later and know this is over kill for a 30 amp system but it is what I had already installed.

Does anyone see any issues with this? I wasnt sure sending 30 amps to a 20 amp plug was a great idea but he said the pig tail didnt matter as the motor on the compressor was the big deal. correct me if I am wrong but unlike regular house current at 110 or 120 where an appliance will only pull what it needs, a 220 will send all the amps to that the device that you send it? Is there a grace area on this?? I know my dads 40 amp plasma cutter uses 50amp breaker and it is good to go. I was just wondering about the plug and outlet and pigtail...
 
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Whatever is feeding the motor itself should be 30 amp or higher.

Not sure what you mean about 'feeding amp' portion of your post. If the motor spikes at 30 amp during startup then that's what it will take (until electric supply is cut off by breaker or other means). Being 110 or 220 doesn't matter... the electrical device will pull what it needs to operate. It doesn't pull 50 amps just because 50 amps are available --and-- circuit breakers have no ability to regulate current draw regardless. All they do is cut off the juice all together if it's amp rating is exceeded for a period of time (by heating up and tirpping).

Not sure what pig-tail you're talking about. I'm guessing that the motor is fed by hardwiring and the pigtail is a 110V draw to operate some other portion of the setup? If that's the case and the motor and this 'pig-tail' are drawing from separate circuits to feed various portions of the whole assembly then a 20 amp 110V feed should PLENTY for anything other than the motor itself.
 
First off I love it. 60 gallon 3.5 hp 12.8 scfm at 43 psi and 12 scfm at 90 psi.

I already had my garage plumbed for it. Question though. It says it is a 15 amp compressor that uses a 30 amp breaker. I assume it is because it may spike higher that 15 amp when running hard or during startup. After talking with the home depot guy for a few minutes he suggested a 20 amp plug (12 ga. pigtail wiring) and a 20 amp recepticle outlet. It is all 8 gauge wiring from a dual pull 30 amp breaker to the plug. I put 8 gauge as I was thinking I would run a welder later and know this is over kill for a 30 amp system but it is what I had already installed.

Does anyone see any issues with this? I wasnt sure sending 30 amps to a 20 amp plug was a great idea but he said the pig tail didnt matter as the motor on the compressor was the big deal. correct me if I am wrong but unlike regular house current at 110 or 120 where an appliance will only pull what it needs, a 220 will send all the amps to that the device that you send it? Is there a grace area on this?? I know my dads 40 amp plasma cutter uses 50amp breaker and it is good to go. I was just wondering about the plug and outlet and pigtail...

what do you mean by all that pigtail stuff? Is the compressor setup for hardwiring (i.e. no plug) but you just bought a generic plug setup and wired the compressor to the plug and are going to plug it in?
 
Is this a hardwired compressor? What is your termiation connection on the compressor's power wire? Is it a plug...or just wire ends? If it's calling for a 30A breaker, i wouldn't splice on a 20A plug and socket. Hardwire it the correct way it's supposed to be wired.
 
okay let me clarify. here are the specs from the owners manual
voltage 230V/1ph
full load amps 16
Breakers size 30

Already wired the garage for 50 amps. Using a 30Amp double pull breaker. Reason for a pigtail is because I wanted to be able to unplug the compressor and plug in a welder later. Well that thought is gone and I am going tomorrow to get 10ga. wire and some conduit to hard wire it into the junction box.