Need input on wiring my shop

[72FJ40LandCruiser]

I bought my first home in November. 2 bedroom house, 1073 square feet and has an 18x24 shop. All the wiring in the house was redone in 2003 and the garage was not done and does not have electrical service to it. Now that I'm all settled in, I need to wire up my garage and I don't know where to start. My house has 100amp service. Currently, there are two 30amp breakers joined for the dryer, 4 20 amp breakers for lights and receptacles, and 4 15 amp breakers for lights and receptacles. There are no major electrical appliances in the house except for the 240v dryer.

In the garage, I need 240v service for my MillerMatic 180 welder and the sticker on it shows a draw of 19.5 amp. Eventually I will have an electric oven so that I can powdercoat small parts, though it would be rarely used and I don't think I would need to run the oven the while welding at the same time. I will put in flourescent lights overhead. I need wiring for an electric garage door opener. I would like about 8 receptacles in the garage. It's just me living here, so it's not like I would be running two grinders at the same time on those receptacles or anything like that. I might eventually have a fridge/freezer in there. I will eventually get an air compressor, undecided if 120v or 240v.

Can I put a breaker in my 100amp breaker box and run wiring underground to my shop and put in a subpanel out there? Do I need seperate service to my shop? What size wire should I run underground? There is 30 feet between the house and shop, and about 8 feet inside the house to the box. I figure I will need about 65 feet of wire between each breaker box. I really don't know where to start, and what will be the most economical way to do this while still wiring it the proper and safe way. Can somebody give me some pointers?

 

[Pin_Head]

Either get your electric company to install a separate meter and panel in your shop, or upgrade your existing panel to 200A service and run a 100 amp sub panel in your shop. Plan C would just be to get an extension cord for your dryer circuit in the house to the shop and use it when you need it.

 

[72FJ40LandCruiser]

Either get your electric company to install a separate meter and panel in your shop, or upgrade your existing panel to 200A service and run a 100 amp sub panel in your shop. Plan C would just be to get an extension cord for your dryer circuit in the house to the shop and use it when you need it.

I've already gotten tired of Plan C.

Any roundabout figure for what I should expect to pay the electrical company to install a 100amp service in my shop? We talking about $300, $500, $1000, etc?

 

[Koffer]

Any roundabout figure for what I should expect to pay the electrical company to install a 100amp service in my shop? We talking about $300, $500, $1000, etc?

I would go with a 200 amp svc . makes adding later easier plus the upfront cost is almost nothing from going from 100 to 200 now

It depends on your area . Here I was able to install a 200amp svc for my garage but the kicker was the transformer on the pole was too small for the extra svc so that needed to be upgraded .
They would have done it for nothing but heres where they got me. Since it was not a living quarter I had to pay for the transformer upgrade ($700) and since it was a 2nd meter/non residential I have to pay comm. rates .
Oh but they did give me a free meter pan for the job

 

[-Spike-]

x2 on getting an upgrade at the house to a 200 amp panel. Then run a 70 or preferably 100 amp sub-panel to the shop. 100 amps at the house is too small these days even without the shop.

-Spike

 

[Cruiserdrew]

Yeah-you need way more power. 200 amp minimum.

100amp sub-panel in the garage would be about right. Your compressor is going to draw 20 amps of 240, your welder 20 amps and your plasma cutter 10 amps. Plus you need lights, grinders, and all kinds of other stuff that all sucks power.

 

[fj40charles]

Installing a 200 amp panel in the house may be a good option. However, installing a new panel may require your old house wiring to be up to current electrical code in your city. Something to consider.

I don't see why you could not get by with a 50 amp subpanel in the garage. The oven will draw 30 amps when you're powder coating. The little 180 amp welder will draw 20 amps max. The compressor will draw up to 30 amps when running. If this is a 1 man shop, I think you could get by with 50 amps.

You'd definitely need more amps if you're planning on running a large tig welder and plan on getting a bigger mig welder (250+ amps), and other machinery (lathe, milling machine, etc.,)

I doubt the electrical company would drop another service in a residential house so this may not be an option.

 

[tehcruiser]

This is the way I would do it.
Leave the main panel as is.
Install a 70 Amp 2 pole breaker in the main panel.
Install 100A main breaker sub-panel in shop.
Run 3 #3Awg (rated at 100A) and 1 #6 for a ground in 1 1/4" PVC pipe to the shop.
(For 70A you only need #4awg wire, but I'm thinking in the future if that
100A main panel doesn't work out and you go to a 200A main panel, just change
that 70A breaker to a 100A breaker and you have full 100A available in the shop,
if you'll ever need that much)
Try to run as much equipment as possible at 240vac. Doing that will minimise your
amp draw, that way you can run more equipment at the same time.
Also, if you keep that dryer off, every time you head over to the shop, you'll never have any
problems with nuisance tripping. Just mind your loads and you'll be fine. The worst that could happen is that you trip a breaker and have to reset it.
Here are some possible loads you might be running concurrently.
shop
20amp for air comp
20amp for welder
10amp lights
10amp for misc
________
60amp

house
30a for dryer
10a miscellaneous
__________
40a

 

[fj40charles]

This is the way I would do it.
Leave the main panel as is.
Install a 70 Amp 2 pole breaker in the main panel.
Install 100A main breaker sub-panel in shop.
Run 3 #3Awg (rated at 100A) and 1 #6 for a ground in 1 1/4" PVC pipe to the shop.
(For 70A you only need #4awg wire, but I'm thinking in the future if that
100A main panel doesn't work out and you go to a 200A main panel, just change
that 70A breaker to a 100A breaker and you have full 100A available in the shop,
if you'll ever need that much)
Try to run as much equipment as possible at 240vac. Doing that will minimise your
amp draw, that way you can run more equipment at the same time.
Also, if you keep that dryer off, every time you head over to the shop, you'll never have any
problems with nuisance tripping. Just mind your loads and you'll be fine. The worst that could happen is that you trip a breaker and have to reset it.
Here are some possible loads you might be running concurrently.
shop
20amp for air comp
20amp for welder
10amp lights
10amp for misc
________
60amp

house
30a for dryer
10a miscellaneous
__________
40a

You cannot exceed 50% of main panel rating for a subpanel. 50 amps would be max. Good idea about running bigger wire for any future upgrades.

 

[tehcruiser]

You cannot exceed 50% of main panel rating for a subpanel. 50 amps would be max. Good idea about running bigger wire for any future upgrades.

The wire would also be the most expensive item on this whole deal.
I think a load calc. would be in necessary in order do determine if that 100A panel can handle the additional load from the shop. Although 50% seems like a safe bet, I don't remember anything from the code that limits the current draw to a certain %, other then proper sizing according to load calculations.
But I could be wrong, like they say: There is a first time for everything.

 

[72FJ40LandCruiser]

I think upgrading the house to 200 amps and putting a 100amp subpanel in the garage would be the best option, and would definitely afford additional loads in the garage in the future.

The whole house was rewired in 2003, so I should not have to update anything in the house to get it to code.

So for this project I'm looking at having to upgrade the wiring to the panel from the meter, buy a 200 amp panel, use my current 100 amp panel in the garage, and possibly reuse my old wire from the meter to the panel that I upgraded? I'm thinking all this large gauge wire is going to cost a small fortune...

 

[kulangot]

I went through all of this in 2000 when I built a 24x47 detached garage.

Where I live, if you have above ground power, the power company will run a line out there for free. You just get two separate power bills if you have 2 services and it costs about $10 or $15 bucks more per month just to have the 2nd service. Not a big deal, but if you cheap, that adds up. I figured it was not a big deal.

In my case, I had below ground service, so I had to pay $1200 for them to dig a trench from the line in my yard to my garage. It was about 50 feet. Took a few months to get them to do it. They tied into my existing power line with a surface box and a "thimble" what ever that is. They gave me the meter, can and parts to hook it up for free.

I could have upgraded the panel in the house and run my own line. But in the DC area, it would cost just as much to hire a back hoe, get it inspected and then have the backhoe come back another day to back fill.

I like doing it with 2 separate services because I can see how power I am using in the garage.

If the garage was closer to the house and there were not any obstacles in the way (I had a large deck to go under) I would have probably just run a wire out and put in a sub panel.

I went overboard with a dedicated 200 amp service. I had 4 220 outlets, a bunch of dedicated 110 30 amp circuits, hard core ventilation, industrial lighting, etc. Then, we moved!

At the time so I got an estimate to have power run out there by an electrical contractor and got a quote of $2500.00! I was surprised that the power company wanted less than half for a better solution! Same guy quoted $3500 more to put a few 220 outlets, lighting and a bunch of 110 outlets in. I did it for $500 in materials and pizza in two days with a few cruiser heads. We also put in waaay more than I asked him to bid for. DIY man.

 

[tehcruiser]

I would check with the utility co. if the wire coming to the meter is rated for 200A. Most likely it is, but I've seen it where it wasn't. If you can afford it at this time, upgrading to a 200A panel is your best bet, but reusing that old panel is questionable, depends on what brand panel you have in there. How far is from your meter to the panel? I wouldn't recommend reusing the old wire if it's aluminium.

 

[72FJ40LandCruiser]

I would check with the utility co. if the wire coming to the meter is rated for 200A. Most likely it is, but I've seen it where it wasn't. If you can afford it at this time, upgrading to a 200A panel is your best bet, but reusing that old panel is questionable, depends on what brand panel you have in there. How far is from your meter to the panel? I wouldn't recommend reusing the old wire if it's aluminium.

From the meter to the panel it's probably around 30 feet. My panel is Sqaure D brand, and was new in 2003.

 

[tehcruiser]

From the meter to the panel it's probably around 30 feet. My panel is Sqaure D brand, and was new in 2003.

Definitely reuse that panel. You might have to plug a lot of unused holes with some KO seals, but that's OK.

 

[Cookiemonster]

200amp w/ 100 to the shop indeed.

As far as costs where are you?

First thing to do is contact your local energy provider and ask for cost info on doing the upgrade. This will include the engineering review and the permit process fees.

In essence what they do is an engineer (or deligated rep) will look at their schematics to make sure there is enough juice in the neighborhood, then tell you where it is located and wether or not you need to cut the street up to run new wire to a 200amp service.

My most recent example was a customer just over a year ago who swapped to a 200amp and luckily for me (actuall him) the PG&E main hub was between his house and the neighbors only 30' from where the new box was going in. Had any of his neighbors wanted to do the same they would have had to bust sidewalk & street asphalt in order to make the run.

PG&E charged him just under $1,000 for the "process" which included the engineers review & to have their crew actually install new wire from their hub to the new service on the house. I did the excavation & had my electrician do the conduit work.

 

[72FJ40LandCruiser]

200amp w/ 100 to the shop indeed.

As far as costs where are you?

First thing to do is contact your local energy provider and ask for cost info on doing the upgrade. This will include the engineering review and the permit process fees.

In essence what they do is an engineer (or deligated rep) will look at their schematics to make sure there is enough juice in the neighborhood, then tell you where it is located and wether or not you need to cut the street up to run new wire to a 200amp service.

My most recent example was a customer just over a year ago who swapped to a 200amp and luckily for me (actuall him) the PG&E main hub was between his house and the neighbors only 30' from where the new box was going in. Had any of his neighbors wanted to do the same they would have had to bust sidewalk & street asphalt in order to make the run.

PG&E charged him just under $1,000 for the "process" which included the engineers review & to have their crew actually install new wire from their hub to the new service on the house. I did the excavation & had my electrician do the conduit work.

I can't pay a grand to the electric company alone, and then do my own upgrades on site on top of that. I'll just run a 50 amp subpanel out there and be careful about what I run at the same time if I'm looking at paying a couple grand just to run electric to my small, simple shop.

 

[TomH]

200 amp service would be ideal. Give the power company a call and tell them what you want to do. It could cost anywhere from nothing to several thousand, as Cookiemonster points out. I just went through something similar with the gas company. I need to upgrade my service and they started out at several thousand if a new line had to be run from the street. After the engineers assessment, they came back with zero cost for a new 2 psi meter.

Make the call, ask the question. That way you know for sure instead of guessing.

Tom

 

[Pin_Head]

I have the wire to run a 50A circuit: 6ga THNN stranded copper. 4 different colors too.

 

[Plowboy]

Look at this web site for adding a sub panel Cutting An Opening In A Plaster/Wood Lath Wall There are three pages with a detailed progression for adding a sub panel. take special note of ground requirements