Want to wire up box for welder in garage.

dirtyb115 · Aug 19, 2008

I know, its not really a "tractor" project, but will use the welder for the tractor

.

At any rate, i need to install a box in the garage for an arc welder, problem is my breaker box is almost full. Can i get by just putting a separate box in just for the welder and maybe my air compressor? If so, what all do i need to get (wire gauges ect.. )
Any adivce is appreciated.

ultrarunner · Aug 19, 2008

I'm not an electrician, but I spend a fair amount of time reviewing projects that involve equipment installation for the job.

I always start with:

Power requirement for the specific Equipment... Manufacturers supply this information or it can be found on the data plate listing voltage and amps.

How far from the existing power panel will the new equipment be located.

Measure the voltage at the existing panel and note the size of the main circuit breaker

You may be able to economize by running one new circuit with one outlet if the compressor and welder have similar power requirements and only one will be used at a time.

vic4news · Aug 19, 2008

Since your breaker box is almost full, you could easily add a sub-panel in order to put in more breakers for the welder and air compressor. A 60 amp panel should be enough. I'd run AWG 6 from the main panel to the sub-panel.

Vic

HoustonBrama · Aug 19, 2008

I agree. I'm assuming your welder is 220V, I'd install a 60 amp double pole breaker in the main box. Then pull you 2 hot, 1 neutral and a ground from the main to a sub panel. That should give you plenty. What size of service do you have coming into the house? You don't want to trip the main breaker every time you weld. If the main service is to small, you'll have to upgrade. That could get expensive.

kennyd · Aug 19, 2008

This thread will turn into a can of worms...

dirtyb115 · Aug 19, 2008

hehe, prolly so.

I took a look at my breaker box today. The box says it is rated for 125 amps. My meter says 200, (which there is no way that is right.). I dont have a main breaker, but instead 4 dual pole breakers on the top half of the box, filling all available slots. One is the AC, one is stove, not sure on one, and then there is a 60 amp breaker that is feeding the lower half of the panel which is all my lights outlets ect..

So on top i have the 60 amp breaker, a 40 amp, and two 30 amp. So already i see trouble if my box is only rated to 125 amps, as i could potentially be drawing 160 worst case scenario correct?
Guess i have to figure this out first, then move on to a subpanel....
Thoughts??

kennyd · Aug 19, 2008

Thoughts??

Yes, Hire an electrician to update your panel, your's sounds very outdated.

gerard · Aug 19, 2008

I'm not an electrician but not having a main breaker would be a problem for me to the point that I'd want the whole panel rewired to at least put a main breaker in. Also I wouldn't be too concerned about the 160 amp potential draw vs the box rating. That assumes you max out every single breaker at the same time and the only way that would happen is if you intentionally TRIED to do it. Get the panel rewired with a main and at the asme time put in the afore-mentioned sub panel to service your garage. Not sure if you have a generator but this would be a good time to wire it so you could have a generator in the garage hooked up and feed the whole house.

HoustonBrama · Aug 19, 2008

Dirty, you're actually not in to bad of shape. If you already have a 200 amp meter, upgrading your current 125 amp box will not to to expensive. I would definitely have an electrician come out and look at it for you. You not having ANY 15 amp and 20 amp breakers for outlets and lights is a real red flag. BUT a relative easy fix depending on how the house is wired.

cperky · Aug 19, 2008

As a licensed electrician I would charge you about $1500.00(parts and labor) to upgrade your main panel to a 200amp panel plus additional for the 220v 50A plug for your welder. Maybe less if some of the current wire or equipment can be reused. I would call a qualified sparky for this job!!

BTW You can't simply add the total of the breakers to get your total load. Breakers are sized to protect the wire from overheating. Search for a residential load calculation worksheet. You may be able to add a sub panel for your welder and air compressor ,depends on the load calculation. If you pull 4 wires keep the ground and neutral seperate in the sub panel.

Here is an excel file that may be helpful:

http://www.naperville.il.us/emplibrary/2005loadcalculator.xls