Upgrading house service How many amps for typical workshop

[hoffman912]

So the house curently has 100 amp service with 30 going to the garage. I am looking to upgrade the house to 200. How much/what size sub panel should I need if I want to have a 60 gal compressor and welding equipment on 240 (ie mig, tig, arc plasma cutter kind of stuff)?

I'm not going to plan on welding all the time, and don't know how to right now, but I want to learn and want to plan for the future. My goal is to restore my 912 in my garage and do all body and paint myself.


So what should I shoot for in terms of garage service? Most of the time I won't need all of it and will likely use the air compressor most for air tools, painting and sandblasting.

 

[zmaxmotorsports]

Is the garage attached or detached? If it was me I wouldn't waste my time with anything less than a 100A service to the garage.

 

[Shadowdog500]

I hired a pro to help figure out my electrical needs. He upped my my house to 200A and ran 100A to my shop. Haven't had a problem in 5 years.

Chris

 

[hoffman912]

It's detached. I was going to try to do separate 200 amp service to the garage. I thought there was already an easement behind it but there isn't so I'm trying to figure out plan b in case I can't get my neighbor to agree to an easement (neighbor behind has a double lot and the lot behind us is empty and just parking and faces an alley so there is a small chance of them allowing it)

 

[hoffman912]

Did you have to upgrade wiring through the house when you upgraded service?

My house is 120 years old, wiring is way old, service is pushmatic style brakers

 

[^&right]

My house has 200 and HAD a 12-2 wire buried to supply the shop. I upgraded by having a 200A panel put in the shop running off a 400A (really a 320A) split meter. This keeps you from paying for 2 meters every month, yet still upgrades to the power supply you need and want. I'm running a 240V compressor, MIG, an oven and a few other appliances so my load is a bit heavier than you are anticipating. That being said, you will most likely add a heavier load at some point and wish you spent $50 more for a 200Amp panel. Really, the cost difference upgrading from a 100A panel to a 200A during install is a no brainer. Very minimal. I filled out a worksheet for my provider and they installed a 50,000 watt transformer to replace the 25,000 watt that I originally had coming in from the street to eliminate power fluxuations. They set a new pole (their cost), put in the new transformer and buried upgraded line to my shop. My cost on that was ~$1,500 plus paying the electrician. Though my anticipated loads are higher than most.

Having said that, bite the bullet and spend an extra few $$ and have the 200A panel put in. By the time you pay an electrician to do the upgrade, getting the bigger panel is extremely cost efficient.

 

[75gmck25]

If the house is old and had much lower capacity panel you can upgrade the main panel first (including all new breakers), and then upgrade your circuits one by one.

I still have about four old 15 amp circuits on my panel that are used for ceiling lights only. I pulled out the old metal jacketed cable where I could, but some of it is running between floors and would require too much demo to be worth it. However, the old cable should be fine for these low draw circuits.

For my old receptacles and for all new major items (refrigerator, microwave, bath GFCI's, etc.) I have run new 12/2 cable and put them on 20 amp circuits in the new Square D QO panel. I have a two story house with an unfinished basement, so I could fish from the attic to the 2nd floor and from the basement to the 1st floor. I have been doing this wiring upgrade over the past couple of years, and now only have 2 or 3 receptacles left where I need to upgrade to modern cable and swap it over to a 20 amp circuit.

Bruce

 

[Shadowdog500]

Did you have to upgrade wiring through the house when you upgraded service?

My house is 120 years old, wiring is way old, service is pushmatic style brakers

I had to re pannel my house, then I had to have a 100A service to my shop run from the main pannel in my house. According to the electrician I hired, who is also an inspector from the next town over it had to be done that way in our area (southern NJ, AKA nanny state/nothing is legal here!!).

I found a replacement meter box at Lowe's that had two big 220V breakers that could be used to feed the existing house pannel on one breaker, and provide 100 amp service to the shop On the other breaker right from the meter without even entering the house, but my electrician said that wasn't within code and couldn't use it. (I still wonder why Lowes had it on the shelf, but they were selling burn cans and black iron pipe which are supposedly illegal andnot within code here as well.

Talk to an electrician in your area to see what can and can not be done in your area.


Chris

 

[Jackfre]

I upgraded the old firestarter 100amp panel and ran a new 200amp service underground to the house. I can easily run everything in the house on the 100 amp and so I am putting 100 amps to the new garage. I am wiring all my machinery for 220v. I won't have a problem running one or two machines at a time, which as a hobbyist, will work out fine.

 

[CNGsaves]

+1 to think outside the box OP if you've got really old stuff. Do it once, Do it right.

Go for BURIED service as you'll love not having the aerial **** view all the time and risk of ice storm taking out your electric service.

If garage is closest to PoCo pole where power will come from, you may want to move meter to garage where you'll have bulk of PoCo power and subfeed power in buried conduit to house.

 

[NUTTSGT]

It's detached. I was going to try to do separate 200 amp service to the garage. I thought there was already an easement behind it but there isn't so I'm trying to figure out plan b in case I can't get my neighbor to agree to an easement (neighbor behind has a double lot and the lot behind us is empty and just parking and faces an alley so there is a small chance of them allowing it)

I have a seperate service for my garage, which I upgraded 2 years ago. It was set up as different when we bought the place. 15 years ago, it cost me about $25/mo for the garage, today it's almost $50. I'd guess that you would use about the same as me and I also have AEP. . . . food for thought.


I believe Cutler-Hammer makes a meter base with a space for breakers in the bottom of the panel. This would allow you to put the larger breakers for each panel there or for an A/C disconnect.

If you have that type of base/disconnect installed, the power can be shut off by you when you upgrade the main panel inside the house. You won't have to call the PoCo to pull the meter for you. AEP recently replaced our older meters with the new automatic meters.


EDIT: This is the meter base a friend put in while I was siding his house. He has a 100 amp service in the house which he plans to upgrade and send some power out to his "barn".

 

[Shadowdog500]

I have a seperate service for my garage, which I upgraded 2 years ago. It was set up as different when we bought the place. 15 years ago, it cost me about $25/mo for the garage, today it's almost $50. I'd guess that you would use about the same as me and I also have AEP. . . . food for thought.


I believe Cutler-Hammer makes a meter base with a space for breakers in the bottom of the panel. This would allow you to put the larger breakers for each panel there or for an A/C disconnect.

If you have that type of base/disconnect installed, the power can be shut off by you when you upgrade the main panel inside the house. You won't have to call the PoCo to pull the meter for you. AEP recently replaced our older meters with the new automatic meters.


EDIT: This is the meter base a friend put in while I was siding his house. He has a 100 amp service in the house which he plans to upgrade and send some power out to his "barn".

That is exactly what I wanted to do and the electrician said it wasn't legal in my area. If I could to that, I would have. That way the house can stay as is.

Chris

 

[wyliesdiesels]

What isnt legal? A separate service? I would call the PoCo and inquire about this....I cant imagine that being illegal...

 

[theoldwizard1]

60A is usually more than enough for an "average" DIY garage/shop. Things get close when you are running a plasma cutter, because you have to run the compressor at the same time. If you want to run an A/C at the same time, 60A won't cut it. The simple solution is turn off the A/C before starting the plasma !

 

[volleyball]

I agree with burying the cable and you might as well do your phone and cable if you have in a separate conduit.
I'd do 200A to the house with a new panel. You'll sleep better. Then as far as the garage, it is hard to argue with 100A but even 70A should be enough. You have some high current items and maybe add an oven for powder coating parts but you won't be running them all at once. Get at least 20 spaces as the 240v things will take two each.
You will also want to run data cable in a separate conduit to the garage.