Electrical for shop, question for main panel

[Gaius]

Hello all. I just built a shop out back and am planning the electrical run.

I have an upgraded 200 amp service at my house. It has a box next to the meter with a 200 amp breaker there, and then runs to the main panel for the house that's in the garage.

There are extra lugs off that meter panel, my plan was to install the breaker for the shop there.

Question is, how much can I run to the shop? Can I do another 200 amp breaker? 125? 100? Thanks all for the help.

 

[Gaius]

I read the box a little more carefully. Only 125 amp max on the secondary lugs. Thanks!

 

[wyliesdiesels]

You should do a load calc on the house to know what load you will have running.

What equipment will you have in the shop?

 

[850xpeps]

You should do a load calc on the house to know what load you will have running.

What equipment will you have in the shop?

Most people think 200 amp is sufficient for everything. Now a days a modern home that requires heating can almost use up the 200 amps. Not that you prob couldn’t get away with it and maybe be ok but who know. And if your over and blow the transformer, the poco might hold you responsible.

 

[Gaius]

You should do a load calc on the house to know what load you will have running.

What equipment will you have in the shop?

2 post lift, 240v compressor, 2x 240v welders, and 110v tools like drill press and grinders. Just me working in it.

 

[wyliesdiesels]

Most people think 200 amp is sufficient for everything. Now a days a modern home that requires heating can almost use up the 200 amps. Not that you prob couldn’t get away with it and maybe be ok but who know. And if your over and blow the transformer, the poco might hold you responsible.

no way to blow up a transformer in that regard.

the worst that would happen is the primary cutouts would pop (sounds like a shotgun shell being fired off).

Then youre sitting in the dark.

But many PoCos typically run their pole pigs at 200-300% of rated KVA.

 

[850xpeps]

no way to blow up a transformer in that regard.



the worst that would happen is the primary cutouts would pop like a shotgun shell being fired off.



Then theres no power.



But many PoCos typically run their pole pigs at 200-300% of rated KVA.

You may be correct. Unless maybe it’s an old one? I’m not sure. But around here they won’t stand for coming out for free and replacing the blown fuse on the tap too many times before they tell you that you need to upgrade.

 

[Gaius]

House is small, gas heat, gas range. A/C unit is pretty small too. 200 is plenty.

 

[u3b3rg33k]

no way to blow up a transformer in that regard.

the worst that would happen is the primary cutouts would pop (sounds like a shotgun shell being fired off).

Then youre sitting in the dark.

But many PoCos typically run their pole pigs at 200-300% of rated KVA.

I got 200A service in my garage. they asked what I was installing, I told them two tesla car chargers, a welder, air compressor, and electric heat.
they said "no problem". there's 12 houses served by the same pole transformer, most likely have 100A service because of their age and size. I think it's a 35 or 50kVa transformer.

 

[u2slow]

But around here they won’t stand for coming out for free and replacing the blown fuse on the tap too many times before they tell you that you need to upgrade.

Seems unlikely unless you're the only consumer on that xfmr, and draw more power than the PoCo initially connected you for. Your own main should trip before the utility's cutout.