detatched garage

[SamC]

can a 30amp 2p branch breaker located in a 16 circuit Sq D load center be considered the main disc for this pnl? If I label it as such?
Thanks
ps : located in ontario

<font color="#a62a2a" size="1">[ July 14, 2002 11:01 PM: Message edited by: SamC ]</font>

[electric-ed]

Hi Sam,
Are you referring to what is called "backfeeding" this 30 amp breaker and using it as a "main" or disconnect for the same panel that it is mounted in?

I haven't seen it done in this area, but I have heard the guys talking about doing this in some of the US discussion boards.

I can't find any rule in the CEC that prohibits it, unless it violates the CSA listing criteria for the panel, by being considered a "modification" of the panel. You could run it by your inspector and see what happens.

Anyone else got any ideas on this?

<font color="#a62a2a" size="1">[ July 15, 2002 08:13 PM: Message edited by: electric-ed ]</font>

[SamC]

Hi Ed How ya doin Thanks for the reply.
Backfeeding through a 2P branch CB is exactly what I'm talking about Ed. I thought about doing this a few yrs back on a simualar project, but customer ended up buying a 60a comb PNL, so I never had a chance to consult the inspector. I can't see a problem as the 30A 2p breaker located in the house PNL will protect the U/G cable as well as the garage PNL, the breaker I would like to use in the garage panel will really only be a disconnect sw. And if it is labelled as such there should be no problem. I've also read on some American forums where this was done, if PNL manufactures allow this in the U.S why wouldn't the CSA allow it here?
I see Tony M from Ontario ESA has joined this forum, I look forward to hear what Tony has to say on this subject, as well as anyone else from who may have considered/done this before. Thanks
SamC

[Tony Moscioni]

"Back Feeding" Of Moulded Case Circuit Breakers And Panelboards

Bulletin 14-5-0

Rule 14-418 (page 84)

The following does not apply to a panelboard used in service entrance applications as Canadian Standards
Association Standard C22.2 No. 86 requires a barriered main disconnecting device.

It is a common field practice to wire an individually mounted circuit breaker with the top as line side and the bottom
as load side. In an effort to reduce installation cost as an alternative when it is not otherwise practicable to provide a
main disconnect there has been an increase in the practice of "back-feeding" circuit breakers, i.e., terminating the line
conductors on the "Load" side of the breaker and the load conductors on the "Line" side.

The following are
guidelines to be followed before approving such an installation:

1. The circuit breaker must be certified and must not have any marking identifying line and/or load terminals,
e.g., most GFCI circuit breakers must not be back-fed as there are definite line and load terminals.

2. The circuit breaker must be of the non-interchangeable thermal magnetic trip or factory sealed
interchangeable trip type or constructed with a solid state trip circuit.

3. The breaker must be permanently marked to identify the actual line and load connections and the circuit
directory card marked in a permanent and legible manner as the main breaker. Interchangeable trip circuit
breakers must be factory sealed against inadvertent cover removal. A suitable number of cover screws
epoxied over, or other similar method of ensuring against inadvertent cover removal, are acceptable.


As an extension of this, a branch circuit breaker in a panelboard is often back-fed and thus utilized as the main
breaker for the panel board. This practice may be accepted provided that, in addition to the above requirements, the
circuit breaker is also identified on the panelboard trim, breaker and on the circuit directory card as the main breaker.

The preceding does not apply to a panelboard used in service entrance applications as Canadian Standards
Association Standard C22.2 No. 86 requires a barriered main disconnecting device.


Tony Moscioni
Electrical Inspector
? Electrical Safety Authority - 2002

[SamC]

Thanks Tony and Ed for your responses.
SamC

[chrisd]

Just a note:

This practice has been made illegal in my province (BC)suposedly because of the danger of someone thinking that the load terminals (or the terminals that one would expect to be the load terminals) are still live with the breaker off.
We like to protect the unqualified to promote tampering.

It was up until just recently that you could still buy small combination panels that were approved back fed main panels. They even have a barrier to contain the service entrance. They are now off the market here.

I would have to wonder however , what the interrupt capacity of a back fed breaker is. The magnetic arc chutes would not work properly.

Chris D