Max subpanel breakers

[justsam]

I recall in some past threads reading about a maximum number of breakers in a subpanel, if there were NO main breaker and just want to confirm before I add too many. Not that I feel it would be a big deal, but code is code. As I recall the maximum was six (6).

The property consists of a main house, guest house, and detached garage. Service is 400 Amp, with two meters. Each meter has its main breaker co-located with it, 200 Amp. The guest house breaker panel has a 200 Amp main, a 100 Amp feeding the garage subpanel, as well as it's local lighting and plug breakers.

The garage subpanel does not have a main, so now my question(s).
Can I add more circuits at the subpanel?
If I exceed some number, do I need a main at the sub?
Is the number related to breaker positions, or actual circuits, since 240V is one circuit, yet two breaker positions.

 

[dave*99]

Your subpanel in the garage is protected by the 100A breaker in the main panel. You can add breakers to the subpanel in the garage up to the panels rated capacity. No need for a main in that garage panel.

You recollection of "6" breakers does not apply here. There is a rule that it must take no more than 6 "throws" of breakers to disconnect all power. There are some old panels around that support this design.

 

[theoldwizard1]

Can I add more circuits at the subpanel?

Your subpanel in the garage is protected by the 100A breaker in the main panel. You can add breakers to the subpanel in the garage up to the panels rated capacity.

Concur

If I exceed some number, do I need a main at the sub?

No need for a main in that garage panel.

I don't believe that is current code. A main is not required on a sub if the sub is located in the same "room" and within a certain distance.

Is the number related to breaker positions, or actual circuits, since 240V is one circuit, yet two breaker positions.

Don't exceed the rating of the sub panel, 125A in your case. Add up the current for each breaker.

Upgrading to current code (i.e. installing a main breaker) is only required if you are doing "major" renovation, like adding a new garage load center/sub panel.


Picture is a little fuzzy. What size (current) are the 240V breakers and what are they used for ?

 

[justsam]

In regard to being in the "same room" the garage subpanel is not in the same room that has the 100 Amp breaker feeding it. AS stated it is fed from the guest house, which is about 150 feet away from the detached garage where the subpanel is located. If it makes a difference, the panel at the guest house is surface mounted and is located on an external wall of the guest house, and is not inside it.

The 240V breakers are for Compressor, and TIG welder.

Construction was done in 2006, and all electrical was done by a licensed electrician.

I am not looking for extra work for myself, just want to be sure I can add breakers. If I need to also add a main at the garage subpanel, than so be it.

 

[pattenp]

The detached garage needs to have a main disconnect if the number of breakers/switches in the sub-panel exceed 6. If the sub-panel is in the same structure as the main service panel from which it is fed then a main disconnect for the sub-panel is not needed when the breakers/switches exceed 6.

 

[wyliesdiesels]

Your subpanel in the garage is protected by the 100A breaker in the main panel. You can add breakers to the subpanel in the garage up to the panels rated capacity. No need for a main in that garage panel.

You recollection of "6" breakers does not apply here. There is a rule that it must take no more than 6 "throws" of breakers to disconnect all power. There are some old panels around that support this design.

WRONG! If the subpanel is in a detached building and if there is more than 6 breaker handles, then a main IS required!

 

[Alchymist]

Don't exceed the rating of the sub panel, 125A in your case. Add up the current for each breaker.

Not necessary - the total capacity of the breakers in the sub panel can exceed the main breaker. (For example, 125A main, 3 -30 amp and 3- 20 amp breakers total 150 amps, and are quite ok). Load management calculations mean more.....

 

[justsam]

WRONG! If the subpanel is in a detached building and if there is more than 6 breaker handles, then a main IS required!

I am going to assume that the two sets of two 30 Amp breakers for welder and compressor, that are tied together are defined as TWO "breaker handles", not Four.

That then means my current configuration has FIVE breaker handles, and I can add one more 120 Volt circuit, or one more 240 Volt circuit.

I am not trying to over think this, just want to do it once, correctly.

 

[dbonne]

The siemens panel looks like it has provisions for a main breaker. It will cost you less than $100 to install a main in the panel.

 

[pattenp]

The OP's panel being a 125 amps means the panel is not to have MAIN overcurrent protection greater than 125 amps.

 

[pattenp]

You are correct. You currently have 5 handles to cut all the power.

I am going to assume that the two sets of two 30 Amp breakers for welder and compressor, that are tied together are defined as TWO "breaker handles", not Four.

That then means my current configuration has FIVE breaker handles, and I can add one more 120 Volt circuit, or one more 240 Volt circuit.

I am not trying to over think this, just want to do it once, correctly.

 

[pattenp]

If you want a main breaker this one may work... less than $50.

http://www.homedepot.com/p/Siemens-100-Amp-Breaker-Main-Conv-Kit-MBK100M/202253093#specifications