How many main panels can I run off a single service?

[Dick in Wisconsin]

From the main panel in the basement and a 20 y/o drawing from the power company, I think we have a 220v, 200amp service to the house. I am going to build a 1,000sf race shop which will need electricity. I'd been planning on running a 100amp subpanel in the shop off the main panel in the basement.

Now I'm reading that there might possibly be a way that I can run a second 200amp main panel after the meter (but before the existing main panel?) directly to the shop (the meter is on the back side of the house, near where the shop will be).

This would allow me to:

1. NOT have try to get the cable from the existing main panel in the basement through the wall and to the shop.

2. allow me to run the appropriate wire from the meter to the shop.

3. allow me to have a 200amp panel in the shop.

All of this is contingent on there being enough or the right "lugs" in the "thing" that the meter is fastened to on the outside of the house.

Is this correct? Thanks

 

[FluxCore]

Yup, basicly.

Here's the deal with the power company and existing service.....Odds are your existing drop and maybe even the nearest transformer on pole aren't sized to support additional 200 amp service EVEN if your existing meter base has provision for it.

I performed my own upgrade 20 years ago with no problems-didn't call anyone, jst yanked the meter and double tapped meter base....meter reader asked why seal was cut, looked at new install, then applied new seal......

Years later I built my folks house next door and power company had to up grade transformer...it was at that point when they did survey they bitched about my additional draw to shop and claimed their data didn't show it, or they would have know to upgrade transformer years ago....They also had to upgrade my drop to meet their specs.

It's best to work with them now....They will usually support upgrade free if their drop or transformer needs replaced.....The worse that might happen is you need to replace meter pan to higher capacity.

 

[DekeT]

What is correct is what answer you get after you talk to your energy supplier.

 

[Gary S]

What is correct is what answer you get after you talk to your energy supplier.

Bingo! Your power supplier owns the meter and line. They have final say on these things.

 

[FluxCore]

What is correct is what answer you get after you talk to your energy supplier.

Generally speaking, your power company needs to know your plans/requirements....They are responsible for supplying sufficent, reliable and SAFE capacity to all on the grid.

You as an end user, know only your needs and will try to get what you need with as little trouble and cost to you as possible...same as me.

Remember this....Your power company can refuse to continue service, or connect to an install that doesn't meet local/national code, or if it taxes their ability to maintain reliable service....So start with them.

Usually, they will support you free of charge to top of your service drop riser as long as what you install downstream meets their basic requirements.

They will want to determine expected total loads you might place on them, then perhaps reconfigure their side to support your expansion....It is NOT unlikely that they might have to upgrade local transformer to prevent you and your neighbors experience sags and equipment damage....Before my utility upgraded transformer, me and my folks went thru many capacitors on our home A/C units

 

[Executive]

If every sub panel originates in the 200 amp main panel and is properly connected on the load side of the 200 amp main breaker, you can put as many sub panels as you want provided there is physical room for each two-pole sub feed breaker.

Chris

 

[Executive]

sorry moderator,
don't know why I keep double posting...

Chris

 

[930dreamer]

I'm trying to understand this; I have a 200 amp line but a 125 amp service in my shop. I added a 100 amp breaker (to the main panel) to test start a 30 hp three phase motor. No issues starting, but I know the 6 ga wire is to small for a permanent solution. I since removed the 100 amp breaker. Will a 3ga. wire fit in to a 100 amp breaker?

 

[Executive]

I'm trying to understand this; I have a 200 amp line but a 125 amp service in my shop. I added a 100 amp breaker (to the main panel) to test start a 30 hp three phase motor. No issues starting, but I know the 6 ga wire is to small for a permanent solution. I since removed the 100 amp breaker. Will a 3ga. wire fit in to a 100 breaker?

A three phase 30hp motor is listed at about 88-90amps @ 208 volts. 100 amps is a reasonable breaker size with the right inverse time breaker. You can upsize this breaker up to 300% (dont have code book handy so we'll have to double check) for motor start up. You are correct in suggesting that #6 is too small. A #3 copper conductor is more appropriate and should fit fine in the 100 amp. You must also size the thermal overloads in your magnetic starter correctly especially if you end up having to upsize the breaker.

Chris

 

[FluxCore]

All breakers will accept whatever size copper conductor is required to feed off them within their rated capacity. Those rated for alum have larger lugs and will accept parallel copper, not that you would want to do that.

 

[Charles (in GA)]

Will a 3ga. wire fit in to a 100 amp breaker?

Read the fine print on the face or sides of the breaker. It will tell you the wires sizes it is approved for, and the torque required on the screws.

Charles

 

[mrobins297aaa]

100 amp breaker will take up to 2/0 wire.............I know because that's what i used to feed my 100 amp panel in my barn

 

[mrobins297aaa]

Read the fine print on the face or sides of the breaker. It will tell you the wires sizes it is approved for, and the torque required on the screws.

Charles

that's good info charles...........I never new that, thanks