Tool Talk

General Category => General Discussion => Topic started by: amecks on April 21, 2016, 06:03:57 PM

Title: Help with garage electric circuit
Post by: amecks on April 21, 2016, 06:03:57 PM
I have a Sears 5 HP compressor on a dedicated circuit.  The 15 amp breaker trips occasionally and the owners manual says if that happens, to run it on a dedicated 20 amp circuit.

It's easy to change the breaker but how do I know if the wire is OK to handle 20 amps?  What gauge would it have to be?

Is there a certain type of breaker I should look for?

Thanks
Al

Title: Re: Help with garage electric circuit
Post by: mvwcnews on April 21, 2016, 06:22:37 PM
If your local public library hasn't fallen prey to the "its all on the internet" virus & ditched all the "How to .. " books, you could use that source to research.
The answer varies depending ... Since NY is such a strong  "union" state, you may not legally be able to modify your own wiring.

When I built my (stand alone) garage, I used 12 / 3 for all the wiring, and 20 amp breakers.  I fed 220 into the garage so it would have enough potential to carry a  welder etc.  All the circuits are  protected by ground fault circuit interrupters.
Title: Re: Help with garage electric circuit
Post by: international3414 on April 21, 2016, 06:31:14 PM
isn't rule one ,14 gauge 15amp,and 12 gauge 20 amp,can that ever change?,i dont think so. :undecided:
Title: Re: Help with garage electric circuit
Post by: amecks on April 21, 2016, 07:55:37 PM
I was just out working in the garage and checked.  The breaker is a 20 amp and the wiring is marked 12 ga on the cover.  So if I already have a 20 amp circuit is there a special breaker that I can get that will eliminate the tripping?  Like in the old fuse boxes there were "slow" fuses?
Al
Title: Re: Help with garage electric circuit
Post by: gibsontool on April 21, 2016, 08:09:56 PM
Most motors will say on the ID plate what it's AMP draw should be, you can put a meter on it under load and you should be able to find out what it is actually drawing. You may have a problem with the motor. I don't have the correct meter to do this, nor do I know how to do it, but a couple of my buddy's know how and have the rigging. Good luck with it.
Title: Re: Help with garage electric circuit
Post by: turnnut on April 21, 2016, 09:10:32 PM
 " dedicated circuit "    nothing else on that line.

  I have the Sears oil less compressor wired the breaker with nothing else on the line, and have not had any problem.
  using 12/3 wire.

  I'm not sure if they make a slow trip breakers like we had for fuses.
Title: Re: Help with garage electric circuit
Post by: Bill Houghton on April 21, 2016, 09:12:35 PM
The nameplate on the motor should show what the amperage draw is.  As a rule, it's best not to try a motor rated at more than 15-16 amps on a 20 amp circuit; it will draw more than that when starting, even if the motor's got a clutch so that it can come up to speed before running the compressor (and if it's starting the compressor from start, it'll likely draw heavy amps).

There are slow blow breakers; if your local big boxy store staff look blank when you ask, find a commercial electric supply shop that will talk to civilians.
Title: Re: Help with garage electric circuit
Post by: amecks on April 22, 2016, 07:45:56 AM
I'll go today to the electric/plumbing place up the street from where I work.  They should have a slow breaker.

The wiring should be adequate so this should solve the problem.

Thanks for the advice. I'll let you know how it works.
Al
Title: Re: Help with garage electric circuit
Post by: turnnut on April 22, 2016, 09:21:17 AM
Al,  write down the model breaker panel and the breaker number to match your new breaker to what you have.
Title: Re: Help with garage electric circuit
Post by: Redneck Albertan on April 22, 2016, 09:44:09 AM
Definitely have the information from your panel with you when you purchase a new breaker. You may just need a new 15 amp breaker. Breakers don't last forever and get weak as they age.
Title: Re: Help with garage electric circuit
Post by: amecks on April 25, 2016, 11:01:26 AM
Well I think it's fixed!  One of the guys on Britbike.com is an electrician and he suggested replacing the outlet.  I checked the outlet and it was only a 15 amp part.  The rest of the circuit is all rated at 20 amps. 
After changing the outlet I have run the compressor two separate times and through quite a few cycles without tripping the breaker. 

Thank you all for the advice.
Al