House has 200A service, proposed shop is also to have 200A. It’s a woodshop with a couple of 30A and 40A outlets for table saw, dust collector, etc., and quite a few 20A outlets on home runs. 4000W of electric heat. About 1000SF of total space.
I’ve only run 100A subpanels in garages and shops before, and of course always from the house. In this case (a) is 200A necessary, and (b) what’s typically the biggest I can pull from the house? The transformer is located such that more than 100 feet of trenching along the road would be needed, right on top of a water line.
I’ll be showing the plans to sparky today but want to see what comments there are here.
Replies
How much equipment will you use at once? 30A table saw + 40A dust collector + 35A (4000W heater) = 105A. If these are the actual draw of the equipment this would put you well over a 100A subpanel. How many amps does the dust collector actually draw? Its hard to believe you could be using more power to filter air than to heat the space!
What's the possibility of a second drop, meter base and everything? Might be easier to connect shop to the power pole than shop to the house.
splat
For my first shop the meter was on the pole and the elec company told me to run a line from my shop to the pole and leave enough to get to the top plus 10 feet. After final insp they came out and hooked it up so I had two lines from the meter, one to the house and one to the shop.
For shop #2 I'm installing a 200 amp pass-thru panel next to the one in the house (both fed from the meter on the opposite side of the wall) and from there going to the standard 200 amp panel in the shop.
You might want to visit the electrical inspector and ask for his suggestion since it will ultimately have to be wired the way he wants it.
Steve.
That's an interesting point... a pass thru of some sort. The electrician had just a few seconds this morning and said that the feed could not come from a breaker in the main panel, but we didn't talk about it further. Avoiding a new run from the existing transformer, or a new transformer, would be a major savings.
Be careful of the numbers people give you:
4000w of heat may be equal to (4000/240) 17amps.
It is real hard to use 100amps at 240 volts.
You can swap out the 200A meter base with a 320A meter base. Then you can run your URD to the new shop. You can put a disconnect next to the new meter base or in the panel in the new shop. WAC 296-46B says the unprotected conductor can enter 15 feet before hitting a disconnect.