Downsizing Main Breaker

O

ocd2boot

Member
Location
Southern California
Occupation
Retired Computer Scientist
If I purchase a 200 amp load center, is it possible to change the main breaker to 125 amps?

Reason: most of the load centers that have a 125 amp main breaker, don't have as many spaces as I'd like.

Thanks!
 
I am going to lock this thread. We are not allowed to assist a person who is not an electrician to perform their own electrical installation work. I cannot tell if that applies to you, because you are showing your occupation as "N/A." Please PM me to clarify, if you wish to participate in this forum.
 
After an exchange of PMs with the OP, I have decided to reopen the thread. The OP informed me that he is not an electrician and does not intend to do any installation work himself. He is merely looking into options.
 
ocd2boot said:
If I purchase a 200 amp load center, is it possible to change the main breaker to 125 amps?

Reason: most of the load centers that have a 125 amp main breaker, don't have as many spaces as I'd like.

Thanks!
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Maybe. Sometimes its a different frame size once you go below 150A. Sq D does make a 125 in the larger frame size that would match a 200 (QOM2125VH). Im not about others off the top of my head. You could always back feed a 125A plug on breaker in a MLO as yourmain, or use a 125 enclosed circuit breaker ahead of the panel.
 
You probably can install a 125 amp breaker on the buss and use a hold down kit. You just feed the 125 amp breaker and not the 200 amp breaker. Just leave that breaker as is.
I am sure your electrician can figure this out.
 
As general statement, it is usually possible to downsize overcurrent protection from 200A to 125A. An electrician should be able to confirm that and select the right replacement breaker, depending on if we are talking about a meter/main or a separate panel, and whether you need a main breaker in this panel in the first place.
 
Squar D has a large selection of different size panels as do most manufactures. It all depends on what you in need of. Is it physical size or panel or the number of breakers.
 
infinity said:
I would just install a 125 amp EM disconnect ahead of the panel then the 200 amp OCPD is irrelevant.
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This.

I'm sure you can special order an 84 circuit panel with a 125A main breaker, or swap main breakers in a whatever panel. But the goal here is to use easily available commodity materials (best bang for the buck) and get lots of panel spaces without increasing the service size.

Your electrician will know if an outdoor EM disconnect is required. If it is, then you use a 125A breaker as the EM disconnect. Then you just use a 200A panel downstream of that 125A breaker. The 200A breaker essentially becomes a switch (in a really rare and really bad short circuit you don't know which breaker will trip first, but during a slow overload the 125A breaker will trip).

This is essentially the setup in my own home. New 200A panel fed from a 100A breaker in an otherwise empty panel on a 100A service. The plan had been to upgrade to a 200A service, but energy monitoring showed that I never used more than 50A, so no need to bother.
 
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