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Joined: Jan 2003
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I
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Sorry I have not gotten back to this.

by tdhorne
Quote
In order to use a back fed breaker as the required building disconnecting means the panel must be listed as service equipment with a back fed breaker.

Tom I am not deputing that but what article requires that? 110.3(B)?

Is there a panel that can not be backfed and why?

by Buck33k
Quote
It is true that you can forget about the backfed main with 6 breakers or less but only if it is not a lighting and appliance branch circuit panel board. 408.16(A)

Buck I do not see how this changes anything, the overcurrent protection can be (and usually is) taken care of at the panel the feed originates from.

shortcircuit What I was trying to get at but was in to much of a hurry to get across before.

1)You could install a main breaker panel.

2)You could backfed a main lug panel, with a secured breaker and following Tom's post.

3)If you can live with 6 circuits or less you can install a main lug panel, fed it from the lugs and use the 6 or less breakers as the disconnecting means. They will not have to be secured because they are not back fed.

Remember the 225.31 does not require the panel to be shut down only the conductors.

Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts
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Joined: Jun 2004
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S
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Thanx for your interpertations everyone...they have all shed light on the issue.
So if the 20 circuit panel is installed with only 6 branch circuit overcurrent devices, it does'nt require a main disconnect...untill the next electrician comes along and wants to add another circuit, then he must install a main breaker to comply with 225.31

Joined: Jan 2003
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Moderator
Yes that is correct looking at it from just a code standpoint you can install the 20 circuit panel with only 6 breakers and be code compliant.

It would be up to the next person not to violate the code.


Bob Badger
Construction & Maintenance Electrician
Massachusetts
Joined: Jan 2004
Posts: 1,507
G
Member
I respectfully disagree with the blanket statment of allowing 6 mains in this panel. We need to look at 408.14(A) and 408.16(A) and decide if we are limited to a maximum of 2 mains.


George Little
Joined: Jan 2004
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Sorry -Meant to include 408.14, which is the classification of panels.https://www.electrical-contractor.net/ubb/icons/icon12.gif


George Little
Joined: Apr 2002
Posts: 558
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George

I disagree. The overcurrent protection of this panel is the feeder breaker at the house. The overcurrent protection is permitted to be in the panel or anywhere on the supply side of the panel. The only issue here is the number of disconnects permitted. As the others have said you can not have more that 6 breakers in this panel unless a main breaker or other disconnect is installed. The disconnect could be a non-fused switch.

Curt


Curt Swartz
Joined: Jun 2004
Posts: 6
B
Junior Member
Thats where I went wrong in my post. The garage is fed from the house with OCP. If Shortcircuits garage had its own service and the six breakers were the only disconnect, then 408.16(B) would apply. Hope I got it right this time!

Joined: Jan 2004
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Curt- Your correct. I owe you a donut and coffee. Next time your in a Krispy Kreme have one on me. :-)
I was thinking along the lines of providing overcurrent protection for the panel.


George Little
Joined: Jun 2003
Posts: 1,143
D
Member
WARNING - I don't have my Code with me, so I can't look this up myself. Apologies in advance for possible idiot factor.

The garage isn't operating under independent service... it's being fed from an OCP inside the house.

With one throw of the hand, you can D/C everything by turning the 60A in the house off, correct? (and secure by LOTO since no line-of-sight if needed)

So why would this still fall under the "6-throw" limit, if _not_ fed by a service separate fro the house?

Joined: Jan 2003
Posts: 4,391
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Moderator
Doug I like the clear warning. [Linked Image]

This application is covered in Article 225 Outside Branch Circuits and Feeders.

225.31 is the section that requires a disconnect and 225.32 tells us where the disconnect has to be. The disconnecting means shall be either inside or outside at a readily accessible location nearest the point of entrance of the conductors. There are also some exceptions but they are not applicable to a detached garage.

225.33 limits us to not more than six switches or six circuit breakers mounted in a single enclosure, in a group of separate enclosures, or in or on a switchboard as the disconnecting means.

Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts
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