Thread: Air Compressor Amp Draw

Shared circuit?

Or crap wiring.

Or your compressor is dying.

Originally Posted by luvtolean

Shared circuit?

Or crap wiring.

Or your compressor is dying.

Shouldn't be crap wiring - the house isn't even a year old (but that doesn't eliminate that theory).

I may have them check for a shared circuit but there is really nothing else on in the house that would be drawing much.

I hope the compressor isn't dying - it's only a few years old and has been pretty well maintained.

I definitely share your breaker theory, just throwing some other ones out.

House I lived in in Kentucky had kitchen outlets that shared a circuit with the garage. It's not impossible.

Do you have a way to measure the current draw?

Are you using an arc fault or ground fault breaker in there? If so, yank that crap out.

Then, everything GFJ said, make sure you're seeing 12ga wire everywhere, should have a yellow or orange jacket.

Then, realize inrush is probably 25-30a , but breakers have to have more than a surge to trip them so that shouldn't be it.

In the end, Im going with crap breaker or combo long wiring issue.

most likely a wiring issue. Newer homes are using 14ga wire (15a) breakers. Older homes used 12ga wire. 14ga wire heats up much faster.

Originally Posted by BizJetGuy

The house just doesn't have the access needed to install heavier wiring for a 20A breaker so that isn't an option.

If the breaker box is in the garage, an easy fix is to run a 12 ga 20amp circuit for the garage. You really need 20 amps for tools like this.

It may also have a startup capacitor that is failing on the compressor. This causes a much larger current surge on startup.

Lots of good tips so far...but I'll add one in case you haven't already tried it...

Home compressors have shit unloaders, or none at all...and will generally be hard to start with the low voltage conditions that you most likely have.

It's a pain in the ass, but you can bleed it down every time you are done with it, and it will start easier, and continue to restart while it's up to temp....

At any rate, a circuit upgrade is in order...

Originally Posted by SomeStrangeGuy

Are you using an arc fault or ground fault breaker in there? If so, yank that crap out.

Then, everything GFJ said, make sure you're seeing 12ga wire everywhere, should have a yellow or orange jacket.

Then, realize inrush is probably 25-30a , but breakers have to have more than a surge to trip them so that shouldn't be it.

In the end, Im going with crap breaker or combo long wiring issue.

There are two outlets in the garage and the one at the far side (third bay) is GFCI. I didn't think about that - you may be on to something.

That's the easiest fix so I'll yank that one ASAP and see what happens.

As for running a 12ga 20A run from the panel to the garage - that's all but impossible unless I rip out tons of sheetrock. The panel is in the basement on the opposite side of the house and the garage, while attached, is about as standalone as you can get while still being part of the house.

Thanks for the brainstorming

Originally Posted by abtech

It may also have a startup capacitor that is failing on the compressor. This causes a much larger current surge on startup.

yes, thats a good possibility, especially since it seems to be a startup issue

I'm somewhat of a bonehead...I had 12ga in my old place.
Here, I have a ~6 year old 26gal compressor in the garage running on a 15a circuit wired with #14 wire that is roughly 55 linear feet from the panel. Its on a shared circuit with other random crap.
Never had an issue with it.

I did have an issue in one of the bedrooms with a vacuum cleaner tripping one of the breakers when we first moved in. Finally figured out it was a trash breaker. New breaker and no problems since.


Not sure why Im just realizing this now....but thought I would share.

Originally Posted by SomeStrangeGuy

I'm somewhat of a bonehead...I had 12ga in my old place.
Here, I have a ~6 year old 26gal compressor in the garage running on a 15a circuit wired with #14 wire that is roughly 55 linear feet from the panel. Its on a shared circuit with other random crap.
Never had an issue with it.

I did have an issue in one of the bedrooms with a vacuum cleaner tripping one of the breakers when we first moved in. Finally figured out it was a trash breaker. New breaker and no problems since.


Not sure why Im just realizing this now....but thought I would share.

That's actually good to hear. Similar situ here - about a 50' run with (what I'm guessing is) 14ga wire with a 15A breaker.

I never had an issue with this compressor at our previous home, with similar parameters (minus the GFCI outlet). We are still under our new home warranty and are due for our 11 month check-up. I'll request that they change out the breaker at that time.

BTW - the compressor is 2HP / 25 gallon and is about 4 years old.

Originally Posted by luvtolean

I definitely share your breaker theory, just throwing some other ones out.

Much appreciated - gives me some other areas to look...

Originally Posted by Baketech

At any rate, a circuit upgrade is in order...

How are you at drywall?

I smell a volunteer

If you pop the GFI does the compressor even get voltage?

If it's on a GFI receptacle chain I'd expect the GFI to pop first, but I have heard of funky breakers doing things behind GFI's.

Originally Posted by abtech

It may also have a startup capacitor that is failing on the compressor. This causes a much larger current surge on startup.

That's what I was getting at with the "compressor dying".

Moving it could've tweaked something in there.

Bake's idea is good to. You should blow it down every night (you use it) anyway.

I used to have breaker popping problems at my house. I ran some 10g for 50ft out to my pool pump and reconfigured it from 110 to 220. My amp draw I assume is now balanced across the two lines at the breaker box.

On my agenda is to swap the AC compressor motor for a 220 motor and locate it out to the shed with a red caged light so I dont forget and leave it on. Plumb air lines back into the garage via copper.

It's a craftsman he said, if it's anything like mine it bleeds itself down automatically

Originally Posted by SomeStrangeGuy

It's a craftsman he said, if it's anything like mine it bleeds itself down automatically

but you can get the parts list online if its a craftsman too. All you need is the part number and you can order a new capacitor if needed. Very nice.

In addition, like has been said, If the cause was GF related the GFI would have tripped.

14ga is small like angelhair pasta!

Originally Posted by BizJetGuy

Much appreciated - gives me some other areas to look...

what type of panel/breakers do you have?

Originally Posted by figment

but you can get the parts list online if its a craftsman too. All you need is the part number and you can order a new capacitor if needed. Very nice.

In addition, like has been said, If the cause was GF related the GFI would have tripped.

14ga is small like angelhair pasta!

My current compressor was a freebie. Brother bought two of em at $100 each. Cheap chinese piece of crap! Anyhow the 2nd thing that went on it was the pressure switch.

I replaced it with this from Grainger at sub$30. Bought one for 90 to 125 psi and adjusted it down to 90psi as thats what my tools tolerate.

Grainger Industrial Supply

Replaced the GFCI plug with a standard and now have a much improved situation. I still may have them look at the breaker for shits and grins.

I didn't realize how slow this was making the motor run - the time difference before and after from trigger point to 150 psi is greatly reduced.

Good suggestion SSG

Originally Posted by G-ForceJunkie

Just make sure that downstream of that plug, it doesnt require (for code) a GFI circut, such as in a bathroom, kitchen, etc. If it does, just replace the next outlet in the chain with the GFI.

I checked the breaker box - there are individual circuits for bathrooms, kitchen, exterior outlets. I'll need to check code but I don't believe the garage is required for GFI.