not enough juice in the shop.

[muddinguy]

So we're renting this house or the problem would be solved already
I'm convinced there is only one circuit going out to the garage. no breaker box in the garage only in house.. and it looks like one run of romex coming into the garage in the corner.. running a small welder my lights cut out.. (i have 4 4' shop lights) and i just picked up a 30 gallong Kobalt air compressor.. now the welder i delt with turn the lights off for minimal draw and more power for the welder.. but the compressor is a big issue.. i fired it up for the 1st time to break it in and i almost thought it was gonna take off.. started up very slowly. but once took off it was fine lights came back on no problem.. ran smooth and pumped up in a decent time. but the next day i was hooking up my air lines and wanted to top off the air the compressor didnt have enough juice to start back up.. motor lugged and turned over very slow while the lights were fluttering trying to turn on.. finally all went out.. hmm ok go in house (well now i know what breaker the garage is) it's a 20 amp breaker.. I have renters insurance but i dont wanna know how well it is cause i burn the garage down.. is there a starter of sort for 110v compressors ?? like a capacitor or something.. If i owned the house id have the garage completely gutted rewired and finished by now..

 

[Charles (in GA)]

Does the compressor run OK if you plug it into a circuit at the house? You don't say, but I gather this is a detached garage. Code only allows one circuit to be run to a detached building. (the one circuit might be a simple 120 like you have, or a 240v subfeed to a panel, but still, only one circuit between the buildings.)

Other issue, is the compressor venting its head pressure at shutdown? Do you hear the loud hiss just as it cuts off? If not, it may be starting against the head pressure, causing it to hesitate and blow the breaker.

Other problem, you may not be aware of if you are not familiar with compressors, is that if you interrupt the operation of the compressor, ie. unplug it or otherwise shut if off before it shuts itself off, it probably cannot vent the head pressure and will have problems starting up the next time. Some Craftsman units had a manual lever on the pressure switch that shut them off, and vented the head at the same time, but this is not real common.

Charles

 

[muddinguy]

yep its most definatly venting the head psi.. which reminds me i need to hook up the auto drain i got a while back at HF..
i did not know that code. that would explain it. i haven't tried plugging into a house circuit.. there is an outlet on the outide of the laundry room maybe ill plug it in there and see if its different..

 

[mdbeck1]

If plugging it in to the other circuit works you can always run a heavy duty extension cord from the house to the air compressor.

 

[Sparks4184]

Before you use an xt cords w/ your compressor, check the manual if you have one and determine the right gauge of wire on the cord (with a ground, btw) per length otherwise you may fry your compressor motor. Your welder probably ought to be on a separate circuit too. To figure out your load, add up the max draw of every device you're running in the shop. Lights, motors, fans, heaters, receptacles, etc.

It sounds to me like you're a bit overloaded. I always keep shop lighting on a separate circuit from receptacles and have dedicated receptacles for things like compressors, etc.

Even though it's a rental, you might do the owner a favor and see if you can pull a sub panel off the main into the garage, say 100 amps in some buried schedule 40 pipe. Maybe ask the owner to either pay for the deal if you do the work or share the cost???

The work isn't complicated and the cable and panel, breakers, proper boxes and receptacles are available at any electrical supply or even HD or Lowes (on a good day). Yeah, you should pull a permit and get it inspected but if you don't know how to do the hookups, you can do all the grunt work and get the wiring in place and then have an electrician do the finish work and wire the cable to the main panel with the right hubs, etc to make it water tight and ensure the ground is good to the new sub panel.
Mark

 

[Charles (in GA)]

On the other hand, the owner may NOT want additional power in the garage, simply to prevent the renters from "running a garage" in there. You never know how some people think.

Charles

 

[muddinguy]

On the other hand, the owner may NOT want additional power in the garage, simply to prevent the renters from "running a garage" in there. You never know how some people think.

Charles

yea im not gonna try and rewire a rental

as long as i can get majority of what i need done im happy. hopefully we'll be in that "married" phase and moved into our own house within a couple yrs

 

[muddinguy]

ok i plugged it into the house and fires right up NO hesitation.. even with the tank at 100psi fired up good..

so yea.. any suggestions on a capacitor ?

 

[muddinguy]

Capacitor ? anyone tried this ?? anyone ? anyone? bueller ?

 

[mdbeck1]

The fact that the compressor works just fine with the extension cord tells us that you are probably correct about being overloaded on the garage circuit and that there's nothing wrong with the compressor.

Unfortunately I don't know much about setting up capacitors for that type of thing.

I'd think real serious about running a heavy duty extension cord to the garage and basically just leaving it until you move. I've been running my woodworking shop that way for over a year. I really do need to get out there and run my underground 240V. Make sure that you roll up the cord before you mow.

 

[muddinguy]

i plugged it into the house to test it.. im not to keen on the ext cord idea basically cause there's a monstrosity of a cord on the compressor and id have to make one hell of an ext cord to run this thing safely.. once running it seems fine just need some electrical boost to get it going.,

 

[was2]

Have you veirifed anything else on the breaker to the garage. If you kill it, does anything else in the house go off? Make sure the only loads weighing you down in the garger are really in the garage. Even the garage lighting may need to be turned off during your testing, or fans, etc. Didn't see details about the lighting in your post.

 

[muddinguy]

I have only killed the breaker once.. i noticed the other day it seems to be starting easier now that its cooled down outside? coincidence ?

 

[hillbilly1]

The problem you have is excessive voltage drop, the wire run to the garage is too small for the load. The compressor makes it worse due to the high amperage it draws when starting up. Since its a rental you could use this, http://autoformers.com/?id=rv2130&loc=inc It is for a 30 amp 120 volt receptacle, but you can use an rv adapter to be able to use it with a regular receptacle. This is all plug and play, so you will not have to do any dangerous electrical work. These are available at any RV (recreation vehicle) supply. The reason the compressor is starting better when it is cool is because the house A/C system was probably not running. When it runs, it also lowers the available voltage to the garage.
I think their a little cheaper than what the link lists.