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Installing Two Panels in a Shop?

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930dreamer

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My shop currently has a messy 200 amp service, I'm in the process of replacing it. I also have a second 200 amp service that is live but not connect to anything( meter, disconnect, pole). If I ran wire for a second panel into the shop should the two panels be close to each other? I'd like to upgrade my three phase shop setup to 480v through a transformer. I currently have a 10hp rotary converter.
 
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theoldwizard1

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Re: Installing Two Panel in a Shop?

930dreamer said:
My shop currently has a messy 200 amp service, I'm in the process of replacing it. I also have a second 200 amp service that is live but not connect to anything( meter, disconnect, pole). If I ran wire for a second panel into the shop should the two panels be close to each other? .
Click to expand...

You are only allowed ONE feed to a building (with a few small exceptions).
 
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Bert_

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Re: Installing Two Panel in a Shop?

You can have more than one panel. But they have to come from the same service and the disconnects must be grouped.
 
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Norcal

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Re: Installing Two Panel in a Shop?

930dreamer said:
My shop currently has a messy 200 amp service, I'm in the process of replacing it. I also have a second 200 amp service that is live but not connect to anything( meter, disconnect, pole). If I ran wire for a second panel into the shop should the two panels be close to each other? I'd like to upgrade my three phase shop setup to 480v through a transformer. I currently have a 10hp rotary converter.
Click to expand...

Only 1 service to a building with limited exceptions, as already mentioned. Going to 480V is going to get expensive to do right.
 
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wyliesdiesels

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Re: Installing Two Panel in a Shop?

Only 1 feed allowed as has been said.

If you go the step-up transformer route, you will be paying to keep the transformer warm.

Have you asked your PoCo how much it would be to upgrade?
 
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Bert_

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Re: Installing Two Panel in a Shop?

A 200A service should run a 10hp converter plus the rest of the shop just fine. Unless you have some other major loads your not telling us about.

I feel like you may have posted pictures in another thread but maybe you could post them again here along with your loads.
 
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9

930dreamer

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Re: Installing Two Panel in a Shop?

Bert_ said:
A 200A service should run a 10hp converter plus the rest of the shop just fine. Unless you have some other major loads your not telling us about.

I feel like you may have posted pictures in another thread but maybe you could post them again here along with your loads.
Click to expand...

Yes, the current rpc will operate all the three phase machines I have. I plan to connect larger air compressor (15-20 hp) in the future. I'm sure the 200 amp will be fine, I pay a service fee on the other meter, better to have it and not need it........
 
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theoldwizard1

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Re: Installing Two Panel in a Shop?

Bert_ said:
You can have more than one panel. But they have to come from the same service and the disconnects must be grouped.
Click to expand...

Disconnects ... like more than one ?

One feed, one (master) disconnect. A subpanel in the same building (at least residential) does not require a disconnect inside of that subpanel. Nice to have, but not required.
 
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wyliesdiesels

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Re: Installing Two Panel in a Shop?

theoldwizard1 said:
Disconnects ... like more than one ?

One feed, one (master) disconnect. A subpanel in the same building (at least residential) does not require a disconnect inside of that subpanel. Nice to have, but not required.
Click to expand...

NO youre thinking of the wrong thing. think of a multi-lug meter pan (not a meter main with a disconnect) with several disconnects coming off of it for feeds to several subpanels. The disconnects all need to be grouped in the same place.
 
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Bert_

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Re: Installing Two Panel in a Shop?

theoldwizard1 said:
Disconnects ... like more than one ?

One feed, one (master) disconnect. A subpanel in the same building (at least residential) does not require a disconnect inside of that subpanel. Nice to have, but not required.
Click to expand...

Could have two service disconnects off the same meter. They would need to be grouped.

Common example is a 400A service feeding two 200A main panels.
 
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Bert_

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Re: Installing Two Panel in a Shop?

930dreamer said:
If I build another shop I'll have it already.
Click to expand...

If it powers nothing just have it shut off. Can always reconnect later. Why pay a monthly service charge?

Unless it doesn't meet current rules. Then the Poco won't hook it up until you correct it. They can't make you do anything if you keep the service active.
 
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theoldwizard1

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Re: Installing Two Panel in a Shop?

wyliesdiesels said:
NO youre thinking of the wrong thing. think of a multi-lug meter pan (not a meter main with a disconnect) with several disconnects coming off of it for feeds to several subpanels.
Click to expand...

Never dealt with a multi-lug meter pan. I am sure they exist, but a meter main sounds like a much better idea.

wyliesdiesels said:
The disconnects all need to be grouped in the same place.
Click to expand...
Sounds a lot like a meter main, except that the disconnects are not inside the same housing as the meter ! :bounce:
 
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Bert_

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Re: Installing Two Panel in a Shop?

nadogail said:
Don't all six need to be in the same panel?
Click to expand...

Nope. Could be different boxes for each disconnect. They just need to be in the same area.

theoldwizard1 said:
Never dealt with a multi-lug meter pan. I am sure they exist, but a meter main sounds like a much better idea.


Sounds a lot like a meter main, except that the disconnects are not inside the same housing as the meter ! :bounce:
Click to expand...

Even meter mains over 200A have more than one main. It's really pretty common. A 320A socket will always have lugs for multiple wires, or at least the option.
 
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jeepxj

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Re: Installing Two Panel in a Shop?

wyliesdiesels said:
Only 1 feed allowed as has been said.

If you go the step-up transformer route, you will be paying to keep the transformer warm.

Have you asked your PoCo how much it would be to upgrade?
Click to expand...

have you run into? what would the use case be?

1. Special conditions [225.30(A)]. These are:

• Fire pumps.

• Emergency systems.

• Legally required standby systems.

• Optional standby systems.

• Parallel power production systems.


and/or:

"
(E) Documented Switching Procedures. Additional feeders or branch circuits shall be permitted to supply installations under single management where documented safe switching procedures are established and maintained for disconnection."
 
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dcg9381

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I thought there were new exceptions in the 2020 NEC that allowed dual-sourced buildings (no cite)?

I agree with jeepxj that prior versions of the NEC included "exceptions" - if the panels were grouped together and for special purposes, such as back-up power...
 
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jeepxj

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on the other hand: good luck getting the local inspector to tell you what documented safe procedures are for a residential application.
 
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Norcal

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dcg9381 said:
I thought there were new exceptions in the 2020 NEC that allowed dual-sourced buildings (no cite)?

I agree with jeepxj that prior versions of the NEC included "exceptions" - if the panels were grouped together and for special purposes, such as back-up power...
Click to expand...

The 2020 is only relevant if adopted by the State the OP lives in (Texas) and to my knowledge only Massachusetts has at this time.
 
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jeepxj

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wyliesdiesels said:
Doesnt matter.

Having 2 power sources can be dangerous especially in a DIY setting.
Click to expand...

Then why does the code include this? I'm not trolling; I agree single cut offs are ideal.


(E) Documented Switching Procedures. Additional feeders or branch circuits shall be permitted to supply installations under single management where documented safe switching procedures are established and maintained for disconnection."
 
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mike93lx

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jeepxj said:
Then why does the code include this? I'm not trolling; I agree single cut offs are ideal.


(E) Documented Switching Procedures. Additional feeders or branch circuits shall be permitted to supply installations under single management where documented safe switching procedures are established and maintained for disconnection."
Click to expand...

Documentation and procedures don't really align with at home DIY. That is really a commercial/industrial thing when you have electricians on staff
 
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jeepxj

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mike93lx said:
Documentation and procedures don't really align with at home DIY. That is really a commercial/industrial thing when you have electricians on staff
Click to expand...

I agree to that. Is there something in the code that states it can't be used in residential applications?
 
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mike93lx

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jeepxj said:
well if we're gona cry code code code and then the code says something is allowed I'd like to at least understand a bit more. guess im doing some digging tonight.
Click to expand...

Code is one thing. What battles you have to fight with your Ahj is another. The documentation and procedure wording is ambiguous enough that they could have an out saying it isn't up to snuff.
 
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