Need some suggestions to beef up the electrical/power capacity in my garage.

Inzane · 01-12-05, 04:20

I've been having a problem with the electrical system in my garage and I know I'm going to have to do something soon to fix it. Occasionally I've had my breaker trip due to overloading.

My two-car attached garage has:
- two overhead spotlights (incandescent I think, not sure on wattage). The "main" light in normal circumstances in the garage.
- a non-permanent flourscent fixture (just one, mounted on the ceiling) - plugged into one wall outlet
- a garage door opener
- an electric driven 5hp, 22gal air compressor (w/ air tools)
- two (x2) twin-500W halogen lamps on adj. stands.
- one portable single 500W halogen lamp that sits on the floor.
- one flourescent portable workllight

Recently in the fall I experienced a problem where if working on my car at night and having 4 (or 5) of the 500W halogens on, as well as the other room lighting, and if my compressor kicked in (using my impact gun or something) then the breaker would trip.

In lieu of fire safety and other concerns with electricals, I'm thinking I may need to seriously upgrade here. Do I need to totally re-wire my garage with additional circuits? Ideally I'd like to have more permanently installed lighting on the ceiling (probably flourescents), and have the capacity to run as many halogen lamps from the wall outlets as I need while polishing cars. How much of this work is easy DIY, vs. needing a professional electrician to be hired?

Thanks.

Accumulator · 01-12-05, 05:07

I'd have an electrical contractor take a look. Shouldn't cost much (if anything) just to get numbers. I'd sorta shy away from DIY electrical work unless you really know what you're doing. Not that it's all that complicated, but it *is* pretty serious business and you wouldn't want to botch it up. And often there are code requirements that could come back to haunt you later (everything from insurance issues if something goes wrong, to lawsuits if someone's hurt, to problems when you go to sell).

FWIW, I'd get a whole separate breaker box put in the garage with a good healthy feed going into it. That way you'd be covered when you do the seemingly inevitable future upgrades.

paco · 01-12-05, 05:25

I'd suggest having an electrian coming out and wiring a separate panel for the garage. That way, you can run dedicated 15 and 20amp plugs. Since it's the garage, you don't need to worry about hiding the lines, just protecting is enough as cosmetics are not paramount.

TW85 HHI · 01-12-05, 05:28

Everything in the garage is on the same circuit?

salty · 01-12-05, 05:50

You would need to give more info to make any suggestions. Is the main power from the house or the power line? What gauge main wire is going to the breaker box? Which breaker is blowing?

Also do you need to run 4 or 5 500 watt lights at a time. A five hp motor will suck the juice and i think would be 15 amp. min. Then 2500 watts of light would be about 25 amps. then other things running might put the total close to 50 amps. When an electric motor starts it really sucks juice.

mirrorfinishman · 01-12-05, 06:05

As already mentioned, you should seriously consider calling in a professional. Think about it, the breakers need to be upgraded, along with heavier gage wire and heavy duty outlets. It doesn't sound like a big job, it's just that it needs to be done correctly.

chaotik · 01-12-05, 06:26

The compressor will take a serious amount of amps at start up...just to give it a "kick" to get running....thats why you are tripping the breaker. But, with all those halogens on also..its no surprise.

I would also consult a pro, if you are not comfortable with working with electric. Like it has been said....its not that hard...but you could run into some issues down the road.

My breaker box is on the other side of the basement (about as far from the garage as you can get).....but I added a twin 15 amp breaker for my 220v plug ( compressor and soon to have welder) Used a HEAVY DUTY plug...so I could unplug the compressor and use the outlet for the welder also.

Ran a dedicated circuit (12 ga wire) for all ceiling fixtures (6 in all ....40 watt T12 flourescents) Then used the existing circuit for half the garage and ran another circuit (again with 12 ga wire) for the other half.

You could use 14 ga. wire, but the nominal difference in cost vs. the extra capacity a 12 ga wire with bigger breaker can give was worth it to me.

Hope you get it worked out how you want it!! Give it some thought on how you want it....what outlets might need/ see more demand, etc. And I would always use GFCI plugs in the garage...even though they might not be code where you live.

MIKE

Pondscum · 01-13-05, 01:24

When a circuit breaker blows, you need to look at the problem and take care of it as soon as possible. Circuit breakers do sometimes fail, and if you're pulling that many amps, you could easily catch your house on fire.

There are two things you need to address.

First, what lighting has been added since the garage/house was built? Some of the lights and perhaps the garage door opener were planned during construction, so these should be OK. However any additional lighting probably needs 2 or 3 additional circuits. You can figure up the number of amps your pulling by dividing the wattage of the fixtures by 120. So a single 500 watt halogen will pull about 4.17 amps. You had two stands which will pull 8.34 amps each or 16.68 amps plus one single which is 20.85 amps total. These three fixtures alone are pulling a lot of juice. You'll need to add two circuits and make sure those two halogen stands are on different circuits.

Next, put in an additional dedicated circuit for your compressor. A compressor of the size you mention is probably pulling 15 amps by itself. It needs it's own dedicated 20 amp circuit to be safe and keep from blowing circuit breakers.

If you have some blank spots on your breaker box, there's a good chance that you can add some additional circuits relatively easily. This is a job for a licensed electrician.