Electrical questions

[tomroblee]

I have a rural home with underground (buried) 200 amp electric service. The transformer sits about 50 ft. from the meter. I am planning to build a detached garage / shop about 50 to 75 ft. on the other side of the transformer.

To supply power to the new building, my options seem to be either running a separate service and meter to the new building or upgrading my existing service to 400(?) amp and trenching a 100 to 125 ft. line from the house to the new building. Installing a separate service and meter for the garage would save on labor and material, but I would have an additional $25 per month minimun fee for the second meter.

Is there some reason why the meter(s) have to be attached to the buildings? If I could locate a 400 amp meter next to the transformer, it would seem that I could use my existing buried cable to feed my house and only have to bury 50 to 75 ft of cable to supply the new building. Is this possible and/or practical?

 

[bmwpower]

Why can't you install a subpanel in the garage and feed it from the house? How much juice do you figure you'd need in the garage?

 

[OldCarGuy]

The solution that I worked out with the local electric company for my electrical needs was to replace the existing overhead transformer and wiring to the 200 Amp 240 Volt single phase service that went directly to my house. And replace it with a remote 400 Amp 240 Volt service located next to a new pad mounted transformer.

I installed the 400 Amp meter box with Unistrut between two 4” diameter steel pipes sunk 3 feet in the ground incased in concrete. From there I fed the 200 Amp load center in the house and four garages each with their own load centers with using thhn copper wire encased in 2” PVC conduit. All run underground eliminating the overhead wires.

 

[FarmerSid]

If he has electric heat, he may need another service to the new shop. I have a 200 AMP service and ran 100 AMP out to a subpanel in my shop. I heat with wood or oil so I had enough power at my main panel to supply the shop. I would run aluminum from your main to a subpanel in your garage using the proper breakers that are designed for aluminum. You could use copper but that will cost you BIG dollars for that run. This way you won't have the extra meter charge from your electric company. If money is no object, upgrage to a 400A main in the house and install a 200A subpanel in your garage.

Money is not too plentifull for me so that's why I ran 100A subpanel out to my shop. If you are a weekend mechanic/fabricator, 100A will be plenty. You will only run into problems when you are running a bunch of things at the same time.

Cheers!

Sid

 

[rancherbill]

I have a rural home with underground (buried) 200 amp electric service. The transformer sits about 50 ft. from the meter. I am planning to build a detached garage / shop about 50 to 75 ft. on the other side of the transformer.

To supply power to the new building, my options seem to be either running a separate service and meter to the new building or upgrading my existing service to 400(?) amp and trenching a 100 to 125 ft. line from the house to the new building. Installing a separate service and meter for the garage would save on labor and material, but I would have an additional $25 per month minimun fee for the second meter.

Is there some reason why the meter(s) have to be attached to the buildings? If I could locate a 400 amp meter next to the transformer, it would seem that I could use my existing buried cable to feed my house and only have to bury 50 to 75 ft of cable to supply the new building. Is this possible and/or practical?

ASSUMPTION
You are wiring the Garage for Non Commercial use.
That you don't use a Electric Heat or Air Conditioners

The cheapest is to run the wire from the house to the garage. The cost for the "middle feet" of the underground wire is cheap. It's the ends at the house or transformer and the garage that's expensive. Adding middle feet will pay for itself probably in a year or less given that you will have to pay $25/mpnth FOREVER for an extra meter.

The other thing is that 200 amp service is misleading. You will probably never be using 200 amp at one time in the shop. You probably never use 200 amp in the house.

Generally a 200 amp circuit is for the theoretical load that might be possible. The big panel give you lots of room for branch circuits.

Check with somebody that's smart locally as to the kind of real load that you are using. The garage will probably need for the worst case 55 amps (30 for welder, and a couple of branch circuits for lighting and fans. You may have a ton of equipment, but, it's not all on at the same time.

 

[tontruck]

You should ask around and find someone with a National Electric Code book, look for the section called "load calculation". You can use their formulas to calulate load on your house and expected load in your shop. This will tell you if you can use your 200A panel and subfeed your shop, or if you need to upgrade to a 400A, or put in a new service. My local inspector requires a load calc. before he will pass your rough inspection.