Air compressor problem- am I correct?

[xs650shawn]

Let me know if my suspicions on this issue seem correct. My air compressor (Husky Pro 25 gallon, oiled pump), will start and fill fine, but when it tries to cycle on again, it will bog down and trip the breaker. I first suspected the unloader valve, but I could hear air escaping each time it shut down. I then tested the compressor on an outdoor outlet on a different breaker, runs and cycles fine. Breaker for the garage is 15 amp, but here is where i suspect the problem to be. The entire garage is wired off a GFCI outlet in the master bath, completely across the house! The breaker is shared by both the master bath and garage, and one exterior outlet in the rear of the house. Could it be a problem with the GFCI outlet, or is it simply too much load for that type of circuit? I am puzzled as to why the builder would've wired it this way, and will probably be having an electrician put the garage on it's own breaker, but it still baffles me. Is this type of setup common? Do I have to expect something similar in another home when I eventually sell this one?

 

[theoldwizard1]

Add a "cold start valve". It is sort of a second unloader. Cheap on eBay (ignore which manufacturer it is spec'd for). They open when the pressure drops below 25 psi and stay open until it goes above that, so install it as close to the pump as possible.

You will probably need a tee to install it.

 

[bigredmf]

Yes that's a lot of potential devices off of one circuit.

Lots of motors tend to trip gfci

Even refrigerators, my garage fridge trips the gfci a few times a year.

I have a small sump pump for draining my pool cover. It will not run off a gfci outlet when it's the only load on the circuit

Red


Sent from my iPad using Tapatalk

 

[crerus75]

I had the same thing happen to me. I was trying to run a small pancake compressor on a garage circuit. Initial fill from low/no pressure was fine, but it would trip the compressor's breaker (not the breaker in the panel) on overcurrent. I could plug it into an outlet in the basement (on a circuit that I had run myself and that presumably had less voltage drop) and be fine. GFCI didn't matter, as the circuit in the basement was a GFCI and so was the garage. I suspect there was simply too much voltage drop on the long run to the garage, and the motor is right at its capacity when trying to pump up a partially full tank.

Some things can make it better. Open the tank drain and run the compressor wide open for 30 seconds or so, longer if it's cold out. This warms up the oil in the pump a little. Run the lightest viscosity oil specified for your compressor. I ran 5W30 synthetic in mine and it made a small but noticeable difference. No, 5W30 isn't recommended, but it's a $90 compressor that I was trying to run in an unconditioned space, so I didn't really care.

In the end, I could never get mine to reliably cycle until a new circuit was run for the garage. I suspect that's what's happening to you, and you might well run into it in the new house as well.

 

[77Mini]

Is it the house breaker or the internal breaker in the compressor? Sounds like you are talking to the house breaker.
Could be the check valve in the compressor or the unloader valve as you mentioned

 

[ez-duzit]

Too much voltage drop. Wiring too small for the distance and load. Run a separate circuit for the garage and compressor.

 

[rpd_fire]

I am not an electrician, but have read enough to be dangerous.

I doubt it's the GFCI. More likely is a weak breaker. Or too long of a run causing voltage drop. This makes the compressor work harder to start, drawing more amps.

Sounds similar to my problem. After much research. Voltage drop.
Detached garage, and it only has a 14/2, 15amp breaker run to it, from the opposite end of the house. About a 100ft run. I have a 2 1/2 horse compressor and it will trip the breaker either on the compressor or in the panel every third time. Currently with the cold, it trips every time with in 10sec.
Plug it in at the house and it runs fine.
Prior to the compressor I never ran anything except a couple lights or maybe a circular saw. Never a problem.

I see an electrical upgrade in my future also.

 

[coljar]

Use a heavy duty extension cord (15-20ft.) and try it on a circuit that is much closer. If it's no better, you can move on to something else. Also, someone above mentioned having a refrigerator on a GFCI. Bad idea and doesn't meet most codes.

 

[CJDave]

I assume this garage is attached. If so, is your dining room on the common wall? Our code calls for the dining room outlets to be on a 20 amp breaker, in case you need to plug in warming plates and such. Tap into the dining room outlet box to feed a new receptacle you install on the garage wall. CJDave.

 

[Cyberbear]

Usually, garage electrical circuits are only made to handle 15 amps. for a light or garage door opener. This saves the contractor money, meets code but causes problems when a garage becomes a shop. Where I'm located all circuits are 20 amp. minimum, and up as needed. I always run a separate electrical feed for any of my garages to avoid problems.
This way an over load situation in the house or garage does not affect each other.

 

[jwh]

What's the current draw of the compressor? I had the same problem with a compressor awhile ago, seem to remember my problem was the electrical run through the house to the garage at the other side with a few stops on the way.

Separate circuit cured problem.

Also, can your compressor be converted to 220 volt? If you're doing a new cable run and breaker anyway, converting would be something to consider.

John

 

[myredracer]

Potentially a voltage drop issue. The motor will draw up around six times it's running current on starting which can be a lot for a 15 amp circuit and the longer the run is, the more the drop will be. I would move the compressor to a receptacle close to the panel and test it there and if okay, your circuit to the garage just isn't good enough.

What is the HP rating and FLA of the motor?

If all you have in the garage is a 15 amp circuit shared by other receptacles in the house, you need at the very minimum, a dedicated 15 amp circuit to the garage. But you really ought to have a few circuits just for the garage and even better, a panel just for it. If wiring back to the existing main panel, and depending on distance, you may want to go min. #12 wire for each circuit.

 

[md21722]

Use a heavy duty extension cord (15-20ft.) and try it on a circuit that is much closer. If it's no better, you can move on to something else.

This is a pretty decent idea. Heavy duty here means 12 or 10 gauge wire. At the "2HP" level some will work fine on 15A breakers (particularly if the distance to the panel is short) and others need 20A. If you have a multimeter or voltmeter you could stick in the outlet or across the contacts of the pressure switch and see what the voltage is.

 

[muncie21]

I had a Craftsman compressor with a similar (same?) problem, minus the GFI complication.

Initial start-up fine, restart after running would trip the breaker. I replaced the unloader and installed a heavier gauge power cord to no avail. Ended up giving the compressor to a friend that didn't have one.

Can't verify it, but I believe that one or more of the starter capacitors in the motor may have been shot. Re-starting with a bit of load on the motor (either friction from running or pressure from the tank/air lines) was causing the breaker to trip.

P.S. I tested the compressor on a dedicated 20amp circuit and it would still trip the break 50% of the time (or more, I only did a few trials) on restart.

 

[The Cobbler]

a cold start valve would probably fix your issue.