Solar ?

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Hendrix

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Can the line side of a feeder be tapped for the solar disconnect as opposed to the line side of the service? The service is at a pedestal 100 yds. away.
 
Yes, but unless you're connecting to the line side of the service disconnect, you must comply with the restrictions outlined in 705.12(D).
 
Pharon said:
Yes, but unless you're connecting to the line side of the service disconnect, you must comply with the restrictions outlined in 705.12(D).
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The line side of the service disco is 100yds away After that a feeder goes to the panel inside the house. I'm thinking that if that feeder is tapped before the panel in the house that it is non compliant according to 705.12 because it is not upstream of the main breaker 100yds away.
 
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It could be compliant, as long as it meets the requirements of 705.12(D). It does not meet 705.12(A).
 
Pharon said:
It could be compliant, as long as it meets the requirements of 705.12(D). It does not meet 705.12(A).
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I should have said that there is a 200a disco, and the solar disconnect is 60a, which isn't allowed unless it is tapped on the service side of the main.
 
Hendrix said:
I should have said that there is a 200a disco, and the solar disconnect is 60a, which isn't allowed unless it is tapped on the service side of the main.
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With a 200A main in a panel with a 225A bus (not uncommon) you could have up to a 75A PV backfeed and not need to use a supply side tap.
 
The feeder from the service disconnect to the panel would have to be rated for 225A also (actually, minimum 217A) for it to be compliant.

The service disconnect also needs to be rated as suitable for backfeed (no 'line' and 'load' markings).
 
Pharon said:
The feeder from the service disconnect to the panel would have to be rated for 225A also (actually, minimum 217A) for it to be compliant.
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Can you cite a code section for that? Unlike the bus, the service wire will never carry the sum of main plus backfeed.
Now LADWP seems to have a rule that the service size (not just wire) has to be greater than or equal to the bus rating regardless of main breaker size, but that is simply a very local outbreak of insanity. (And seems to be ignored except where solar backfeed is involved or a 100 amp service goes into a 200A panel.)
 
GoldDigger said:
Can you cite a code section for that? Unlike the bus, the service wire will never carry the sum of main plus backfeed.
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Good point. I guess I was thinking that if OCPD only existed at that 60A and 200A CB's, then the combination feeder/panel bus would be considered all the same node. But you're right -- power from the 200A service disconnect will only flow in that direction, so the node point is really just the panel busbar.

For the record, I was looking at a reading of the 2011 705.12(D)(2) -- got tripped up where it said "busbar OR conductor".
 
Pharon said:
For the record, I was looking at a reading of the 2011 705.12(D)(2) -- got tripped up where it said "busbar OR conductor".
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Yep, and many inspectors interpret that part of 705 to apply to feeder wires even when all there is involved is the backfed breaker on one end and the PV on the other. No loads at either end, let alone in the middle of the feeder.
[2014] is clearer on this situation.
 
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