If a service panel which has a single service disconnect for a sfd is located on a pole, and there is 1 overcurrent device which supplys a feeder to a panel for a seperate structure, does the subpanel need a single disconnect, or can up to 6 breakers in the subpanel serve as a disconnecting means? I have been under the impression that if there are up to 6 breakers at the subpanel that this acts as the disconnecting means, however one of my co workers believes that the "up to 6 breakers" is refering to other feeders and that a main disconnect is required so that the subpanel ungrounded busbar is disconnected. Check the 2001 CEC section 225-31,32,33,and 34. What do you think? Thank you.
Maximum # of disconects
- Thread starter davidw
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tvgaconsultants
Member
Re: Maximum # of disconects
My understanding of your issue is that you have a subpanel which is feed from a mainpanel with an overcurrent device (ie breaker/ fuses). If this is true then the breaker I believe is your disconnecting device and there for you need no other. The six breakers in the subpanel act as disconnecting means for their branch circuits.
My understanding of your issue is that you have a subpanel which is feed from a mainpanel with an overcurrent device (ie breaker/ fuses). If this is true then the breaker I believe is your disconnecting device and there for you need no other. The six breakers in the subpanel act as disconnecting means for their branch circuits.
roger deas
Member
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- North_Carolina
Re: Maximum # of disconects
Part of the problem is that the forum leaders have decided to take out member info such as "location" and "time in trade".
I have no idea of what the CEC is. I assume (probably incorrectly) this is Chicago Electrical Code.
Roger
Part of the problem is that the forum leaders have decided to take out member info such as "location" and "time in trade".
I have no idea of what the CEC is. I assume (probably incorrectly) this is Chicago Electrical Code.
Roger
Re: Maximum # of disconects
Thanks, Guys:
*tvgaconsultants: The subpanel is in a seperate structure from the svc panel. In the 1999 NEC, section 225-31 and 31 state that a disconnecting means is required for ungrounded conductors at the building outside or nearest point inside the building. The question I have refers to section 225-33 and 34. Are 6 circuit breakers at the subpanel an approved disconnecting means (which would leave the ungrounded busbar hot) or is a single disconnect required (which would disconnect the busbar)?
*Roger: The 2001 CEC is the California Electrical Code, which is the 1999 NEC with the CA ammendments included. I have been a general contractor since 1990, and since 1999 have worked for the County of Mendocino as a building inspector. Thanks again for your responses, David
Thanks, Guys:
*tvgaconsultants: The subpanel is in a seperate structure from the svc panel. In the 1999 NEC, section 225-31 and 31 state that a disconnecting means is required for ungrounded conductors at the building outside or nearest point inside the building. The question I have refers to section 225-33 and 34. Are 6 circuit breakers at the subpanel an approved disconnecting means (which would leave the ungrounded busbar hot) or is a single disconnect required (which would disconnect the busbar)?
*Roger: The 2001 CEC is the California Electrical Code, which is the 1999 NEC with the CA ammendments included. I have been a general contractor since 1990, and since 1999 have worked for the County of Mendocino as a building inspector. Thanks again for your responses, David
david
Senior Member
- Location
- Pennsylvania
Re: Maximum # of disconects
David,
To correctly answer you question more information is needed. From your post I know you have a feeder from a pole service to a separate building. You do not give the size of the service panel in the building or the size of the feeder disconnect. Is the second building panel labeled service disconnect? If so then the six throws of the hand rule would apply. If the second building panel is a lighting and appliance panel and the feeder is protected with over-current protection no grater then the rating of the panel then you would not need a main in your lighting and appliance panel as long as six throws of the hand disconnect the second building.
David L W
David,
To correctly answer you question more information is needed. From your post I know you have a feeder from a pole service to a separate building. You do not give the size of the service panel in the building or the size of the feeder disconnect. Is the second building panel labeled service disconnect? If so then the six throws of the hand rule would apply. If the second building panel is a lighting and appliance panel and the feeder is protected with over-current protection no grater then the rating of the panel then you would not need a main in your lighting and appliance panel as long as six throws of the hand disconnect the second building.
David L W
tvgaconsultants
Member
Re: Maximum # of disconects
DavidW,
NEC2002 section 225.31-.33 gives indication that any means of disconnecting the out building from SFD is fine(ie feeder breaker). I agree with your coworker. CEC may be different. The six disconnecting means in the out building leave the panel energized. The intent of section 225 may be to de-engerize the building with a disconnect that is located outside or just inside of the building. Your proposal would not accomplish this intent.
DavidW,
NEC2002 section 225.31-.33 gives indication that any means of disconnecting the out building from SFD is fine(ie feeder breaker). I agree with your coworker. CEC may be different. The six disconnecting means in the out building leave the panel energized. The intent of section 225 may be to de-engerize the building with a disconnect that is located outside or just inside of the building. Your proposal would not accomplish this intent.
- Location
- Illinois
- Occupation
- retired electrician
Re: Maximum # of disconects
225.33(A) clearly permits six circuit breakers to serve as the required building disconenct. Of you also have to comply with 225.32 and .34 and that the outside feeder breaker rating is equal to or less than the building panel rating.
Don
225.33(A) clearly permits six circuit breakers to serve as the required building disconenct. Of you also have to comply with 225.32 and .34 and that the outside feeder breaker rating is equal to or less than the building panel rating.
Don
Re: Maximum # of disconects
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Tom
I don't see how. Since the circuit supplying the panel in question originates at service equipment and is protected by an Over Current Protective Device at it's source it is a feeder rather than a second set of service entry conductors.
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Tom
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