PDA

View Full Version : Check this panel



John Kogel
08-31-2010, 09:16 PM
Here's one to kick around, and I'll answer any questions.

In a 40 yr old house, a 100 amp GE service panel has a 100 amp breaker feeding the remote panel. A licensed electrician did the wiring and the work was approved by the local electrical authority. Where I live, electrical inspectors are trained electricians. So these two electricians said this was good work.
The label says the max breaker size is 70 amps. :confused:
I am merely a home inspector. Is this a mistake?

Roger Frazee
09-01-2010, 10:11 AM
Your correct John

They have exceeded the bus stab rating for the panel and it also appears that they can only have a sum of 300 amps total in circuit breakers connected to a single hot leg bus bar.

The 70 amp per bus stab is fairly common in the USA for 100 amp panels. The way that works is if I connect a 70 amp double pole breaker to protect a feeder to a panel then I cannot have a breaker adjacent to it as I have maxed out that bus stab. Like so .. Notice also that the two single poles above the 70 double have that bus stab maxed out....ie... they both cannot be 40 amp single poles.

I have a reply back from square d from their technical department when I inquired about this some years ago during a service equipment upgrade and subsequent added panel.

Roger Frazee
09-01-2010, 10:20 AM
Forgot to mention that the argument you will get is that the labeling is speaking of calculated connected load. Which led to my inquiry with square d who then verified it is the breaker rating not connected load. The wording seems rather obvious to me but you know how that goes....:)