Sub Panel Amps

[Mark A. Timpani, CMI]

Are there any cases where a sub panel can have higher amps then the main?
Say the main is an old 60 amp service. I go in the house, find a sub panel in the closet and it has 100amp breaker with 4 breakers under it. Is this correct?

[ccbrands1]

not sure of what the code is, but your weakest link is the governing factor. (60 amp main breaker in main panel)

your 100 amp sub would never be given the opportunity to draw it's potential amperage.

i guess if the sub was put in with the though of upgrading the main eventuall, it would make sense of why it was installed.

oh, and the sub in a closet is wrong, too.

[Paul W. Abernathy]

Mark,

While anything is possible the factor here would be the Conductor Size feeding that 100A panel in the " Closet " which in itself would be a problem....even if before it was mandated...just a safety issue you should call out..but I digress....

If the panel itself in the " Closet" is rated for 100A.....which being rated alone for that is fine.......you would need to know the following:

1.) If the panel is protected by a 60A breaker in the MAIN...and the conductors going to the "sub" are rated for the 60A...it would be fine for the panel in the " Closet" to be rated at 100A....

2.) Since panels are not based on the TOTAL number of breakers listed amps...but more in diversified loads......just having the (4) breakers in it does not tell us anything.......

Question...is the panel a MLO or does it have a MB?...regardless make sure the sub panels feeder conductors are sized correctly and again just because the panel is rated at 100A...does not mean it's capacity is 100A....remember the 60A breaker feeding it will limit that...as well as the conductor size...make sure it meets the 60A capacity of the breaker feeding it.

Hope this helps

[rwand1]

But you only have 60 amp service so the 100 amp sub panel can never pull more then 60 amps right?

This would only change should the incoming service be upgraded to 100 amp right?

[Paul W. Abernathy]

Raymond-

I went into more detail but basically the long and short is....the 60A main breaker feeding the SUB panel is the ruling factor.....I just would like them to verify the actual "FEEDER" to the sub panel was also rated for the 60A as well.

But yes...if the 60A Breaker is protecting a "sub" and even if the panel itself is rated at 100A ( which really means nothing in this case )....the service is still 60A.......the capacity of the service is still 60A...regardless of the "sub" panels rating......

[rwand1]

Thanks Paul. I confuse easily!

[Paul W. Abernathy]

lol...hey don't we all...

[Mark A. Timpani, CMI]

me too