Panel Upgrade

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new member here - hello everyone

I've got a customer that requires addtional ckts.
He doesn't want to spring for a new service just yet.
The load calculation is less than 100a.

If I were to swap out his 100a main breaker panel with a 200a main breaker panel leaving everything else intact (the wires from the meter as well as the egc ), would this create a code violation ?

Thanks
Philip
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
I think using a higher rated panel will be acceptable, but only if you swap out the new panel's main breaker from a 200 amp to a 100 amp. Others may disagree. That happens here, from time to time. :grin:

Welcome to the forum.
 

cpal

Senior Member
Location
MA
The question might be can you get a 100 A main that the 200 A loadcenter will accept. If you can it might be less expensive to nipple in a second panel. :roll:
 

iwire

Moderator
Staff member
Location
Massachusetts
Strangely enough he could make a service conductor tap into the new 200 amp MB panel and leave the 100 amp panel and conductors alone.
 

Cavie

Senior Member
Location
SW Florida
new member here - hello everyone

I've got a customer that requires addtional ckts.
He doesn't want to spring for a new service just yet.
The load calculation is less than 100a.

If I were to swap out his 100a main breaker panel with a 200a main breaker panel leaving everything else intact (the wires from the meter as well as the egc ), would this create a code violation ?

Thanks
Philip

It would be a violation because youwould be fusing 100 amp wires with a 200 amp breaker. You would also have an EGC undersized. This is why inspectors have jobs.
 

Mr.Sparkle

Senior Member
Location
Jersey Shore
new member here - hello everyone

I've got a customer that requires addtional ckts.
He doesn't want to spring for a new service just yet.
The load calculation is less than 100a.

If I were to swap out his 100a main breaker panel with a 200a main breaker panel leaving everything else intact (the wires from the meter as well as the egc ), would this create a code violation ?

Thanks
Philip

Nah, you can do it.

You could actually just put in a Main Lug Panel and call it a day.
 

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
new member here - hello everyone

I've got a customer that requires addtional ckts.
He doesn't want to spring for a new service just yet.
The load calculation is less than 100a.

If I were to swap out his 100a main breaker panel with a 200a main breaker panel leaving everything else intact (the wires from the meter as well as the egc ), would this create a code violation ?

Thanks
Philip
First off - welcome to the forum.

I believe you would be in violation. Irrespective of the calculated load or what power may be drawn after the main breaker, once you change the panel out it would now be rated for and fused at 200 amps. That means the wiring between the main breaker and the meter and for all intents and purposes the service entrance wiring is only rated for 100 amps. In addition the grounding system is also only rated to clear a fault at 100 amps. Electrically speaking will it work ? Probably so. Would you pass inspection ? Probably not.
 

iwire

Moderator
Staff member
Location
Massachusetts
Bob, Sorry, I don't understand.

That is only because I did not say it well.:)

The NEC would allow him to supply both the 100 and the 200 amp panels from the existing 100 amp conductors as long as the calculated load is under 100.

He would have two service disconnects and of course they would have to be grouped.
 

augie47

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Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
That is only because I did not say it well.:)

The NEC would allow him to supply both the 100 and the 200 amp panels from the existing 100 amp conductors as long as the calculated load is under 100.

He would have two service disconnects and of course they would have to be grouped.

(you are sooooo smart)..
That's one inspection I would have to bless but hate it at the same time :)

Purely my personal preference (not an inspector requirement) would be to install his 200 amp MB panel and back-feed it with a 100 amp branch for now.
(ignorin Bob's perfectly legal route)
 

growler

Senior Member
Location
Atlanta,GA
Purely my personal preference (not an inspector requirement) would be to install his 200 amp MB panel and back-feed it with a 100 amp branch for now.
(ignorin Bob's perfectly legal route)

You can feed the panel with a 100 Amp main that snaps into place but it would have to be a main that is secured ( and marked) . They make a bracket that will secure the breaker in place. I think the last one I used was just a plastic deal to secure the breaker so it couldn't easily be removed.

Buy a 200 Amp main breaker panel and remove the breaker ( for now) and don't even knock out the opening for the main and then install a 100 Amp main ( snap in , secured ) and use the main breaker sticker to mark it. That way there wouldn't be any confusion.
 

iwire

Moderator
Staff member
Location
Massachusetts
You can feed the panel with a 100 Amp main that snaps into place but it would have to be a main that is secured ( and marked) . They make a bracket that will secure the breaker in place. I think the last one I used was just a plastic deal to secure the breaker so it couldn't easily be removed.

Buy a 200 Amp main breaker panel and remove the breaker ( for now) and don't even knock out the opening for the main and then install a 100 Amp main ( snap in , secured ) and use the main breaker sticker to mark it. That way there wouldn't be any confusion.

In Gus's example there would be no need to remove or replace the 200 amp breaker. The feeder to it will already be protected.
 

jaylectricity

Senior Member
Location
Massachusetts
Occupation
licensed journeyman electrician
I'm going to have to assume you're just looking for more spaces in the panel and the customer doesn't want to spend the money on an upgrade, nor should he unless he plans on putting a spa, pool, central A/C, etc.

If you can't put tandem breakers in there to add the circuits, the next cheapest thing is to add a sub-panel.
 

growler

Senior Member
Location
Atlanta,GA
In Gus's example there would be no need to remove or replace the 200 amp breaker. The feeder to it will already be protected.

I see what you mean now, you are talking about adding an additional panel. I read the OP statement of swapping out the panel ( meaning only one). I just hate to see a regular breaker that's back fed as a main, they start out temporary and end up staying for years like that. Yes adding a panel would work nicely, if they have the room.
 

electricmanscott

Senior Member
Location
Boston, MA
I just hate to see a regular breaker that's back fed as a main, they start out temporary and end up staying for years like that. Yes adding a panel would work nicely, if they have the room.

I don't get it. :confused: I do this all the time what's the problem?

As for the op, as pointed out just change out the panel to a ML panel with enough space for your needs and backfeed a 100 amp breaker. Easy job. :)
 

growler

Senior Member
Location
Atlanta,GA
I don't get it. :confused: I do this all the time what's the problem? :)


I think we are talking about different things here. The original post was about swapping out a panel. Protecting the supply conductors with a 100 Amp back feed breaker, main disconnect in a 200 amp panel. When I stated "regular breaker" I was meaning a snap in unsecured breaker, normal for residential use.

In 408.36 (D) they refer to it as plug in overcurrent device ( I would assume that means snap in breaker :grin: ). I was just bringing up the fact that the breaker would need to be secured if used as main disconnect.
 

Cavie

Senior Member
Location
SW Florida
I think we are talking about different things here. The original post was about swapping out a panel. Protecting the supply conductors with a 100 Amp back feed breaker, main disconnect in a 200 amp panel. quote]

I'ts amasing how these posts morph into something different than the OP's write. The OP made no mention of a backfeed 100 amp breaker. He asked if he could install a 200 amp main breaker panel and feed it with 100 amp service wire and a 100 amp EGC.

Simple answer to his question is NO. All the rest are sugestions on how to do it correctly.
 
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