Check the breaker size in this panel

[John Kogel]

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:
Does reducing the breaker for the feeder from 100 to 70 amps seem like a reasonable recommendation?

[Roger Frazee]

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:
Does reducing the breaker for the feeder from 100 to 70 amps seem like a reasonable recommendation?

Certainly would be ... the way it stands they have exceeded the bus stab rating by 30 amps.

[Jerry Peck]

I'm not quite sure what you are explaining or asking ...


In a 40 yr old house, a 100 amp GE service panel has a 100 amp breaker feeding the remote panel.

The label says the max breaker size is 70 amps. :confused:

Does reducing the breaker for the feeder from 100 to 70 amps seem like a reasonable recommendation?

Too many questions needing to be answered (unless I missed the answers):
The label for which panel says 70 amps?
What is the rating of the feeders? The service entrance conductors?
What is the rating of the service panel? The remote panel?

[John Kogel]

I'm not quite sure what you are explaining or asking ...
The label for which panel says 70 amps?
What is the rating of the feeders? The service entrance conductors?
What is the rating of the service panel? The remote panel?The older GE panel in the first pic is the 100 amp service panel. The service conductors, I believe are #3 copper, come in at the top, and the meter is in the box immediately above. This panel has a label, pic 4, showing a maximum branch circuit breaker size to be 70 amps. A 100 amp breaker has been installed in this panel to supply the newer Commander remote panel, rated for max 125 amps.

My quandary is this. If I call for the installation of a 70 amp breaker as called for on the label, in place of the 100, the seller will produce a permit saying the work was approved by the authority, and that a licensed electrician did the work.

The remote panel is also completely full of breakers including a 40 amp for a kitchen range, a 30 amp dryer circuit and a 30 amp heating circuit. The rest of the breakers are for outlets and lighting. The total load on that circuit could exceed 70 amps, but only when the larger appliances are all turned up to max, maybe Xmas day.
On the other hand, those are nice copper bus bars in good condition and the electricians gave it their blessing. Is it really a problem?

Actually now that I'm looking at it again, that feeder to the remote panel is undersized for 100 amps, is it not? And yes, the bending radius is pretty extreme. I'm feeling better about calling it out.

[Jerry Peck]

This panel has a label, pic 4, showing a maximum branch circuit breaker size to be 70 amps. A 100 amp breaker has been installed in this panel to supply the newer remote panel, also rated for 100 amps.

Got it now, thanks.


My quandary is this. If I call for the installation of a 70 amp breaker as called for on the label, in place of the 100, the seller will produce a permit saying the work was approved by the authority, and that a licensed electrician did the work.

To me that would not be a quandary as the panel itself says it is a no-no, and no electrician is allowed to change that. Nor is any electrical inspector. The Chief Building Official, who is the ultimate authority, may do so - unwisely as it would be, and by some codes that would even be against the code to do so. Many Chief Building Officials forget (sometimes only when it is convenient for them to do so) that when they make a decision which goes against what the manufacturer states, they can PERSONALLY be held liable for anything than happens as a result of their decision as they overstepped their authority. At least that is here in the USA.

Several sections of the NEC address this, but the easiest one to remember, and the Canadian Electrical Code may have something similar, is: 110.3(B).

- 110.3 Examination, Identification, Installation, and Use of Equipment.
- - (A) Examination. In judging equipment, considerations such as the following shall be evaluated:
- - - (1) Suitability for installation and use in conformity with the provisions of this Code
- - - - FPN: Suitability of equipment use may be identified by a description marked on or provided with a product to identify the suitability of the product for a specific purpose, environment, or application. Suitability of equipment may be evidenced by listing or labeling.
- - - (2) Mechanical strength and durability, including, for parts designed to enclose and protect other equipment, the adequacy of the protection thus provided
- - - (3) Wire-bending and connection space
- - - (4) Electrical insulation
- - - (5) Heating effects under normal conditions of use and also under abnormal conditions likely to arise in service
- - - (6) Arcing effects
- - - (7) Classification by type, size, voltage, current capacity, and specific use
- - - (8) Other factors that contribute to the practical safeguarding of persons using or likely to come in contact with the equipment
- - (B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

This is where the AHJ gets their approval power:
- 110.2 Approval.
- - The conductors and equipment required or permitted by this Code shall be acceptable only if approved.
- - - FPN: See 90.7, Examination of Equipment for Safety, and 110.3, Examination, Identification, Installation, and Use of Equipment. See definitions of Approved, Identified, Labeled, and Listed.

And that approval, if not listed and labeled, comes from the items in 90.7, 110.3(A) and the definitions of the words noted in the FPN.

Here those definitions:
- Approved. Acceptable to the authority having jurisdiction.
- Identified (as applied to equipment). Recognizable as suitable for the specific purpose, function, use, environment, application, and so forth, where described in a particular Code requirement.
- - FPN: Some examples of ways to determine suitability of equipment for a specific purpose, environment, or application include investigations by a qualified testing laboratory (listing and labeling), an inspection agency, or other organizations concerned with product evaluation.
- Labeled. Equipment or materials to which has been attached a label, symbol, or other identifying mark of an organization that is acceptable to the authority having jurisdiction and concerned with product evaluation, that maintains periodic inspection of production of labeled equipment or materials, and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner.
- Listed. Equipment, materials, or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with evaluation of products or services, that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services, and whose listing states that either the equipment, material, or service meets appropriate designated standards or has been tested and found suitable for a specified purpose.
FPN: The means for identifying listed equipment may vary for each organization concerned with product evaluation, some of which do not recognize equipment as listed unless it is also labeled. Use of the system employed by the listing organization allows the authority having jurisdiction to identify a listed product.

[dana1028]

The installation, as is, constitutes a violation of the listing of the service panel. This is a manufacturer specification...will it ever cause a problem...?? who knows. Is it a violation? Yes.

In code enforcement, this violation would be cited under NEC 110.3(B) - Installation & Use. "Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling."

[Jerry Peck]

In code enforcement, this violation would be cited under NEC 110.3(B) - Installation & Use. "Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling."

Yep, that is what I do.

In home inspection, that would be called "Repair needed - not functioning as intended." as it was never intended to function with that 100 amp branch circuit breaker installed. :D

[John Kogel]

= Roger Frazee 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.

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....:)
Thanks Roger. Sorry about the double posts.