BillK-AZ
Senior Member
- Location
- Mesa Arizona
NEC 2008 690.64(B)(3) states the interconnection point shall be on the line side of all ground?fault protection equipment unless ?Ground-fault protection devices used with supplies connected to the load-side terminals are identified and listed as suitable for backfeeding?.
This was added in the 2008 Code and is confusing.
My problem is schools with 1000A+ 277/480V service entrances with GFP, making this exception apply.
John Wiles, who proposed this addition to the code panel says that the intention was that when adding a PV system to such a system that both the main breaker and the distribution breaker are to have GFP and be listed for backfeed.
A local utility that desires to donate a PV system to such a school has requested that the circuit breaker manufacturer state that the two circuit breakers are listed for this use. The manufacturer will only state listing is to UL 489 and UL 489 makes no reference to NEC Art 690.64(B)(3), but it does make reference to Art 210.12 that requires the GFP feature.
Has anyone had this requirement come up with an AHJ?
How was it resolved?
This was added in the 2008 Code and is confusing.
My problem is schools with 1000A+ 277/480V service entrances with GFP, making this exception apply.
John Wiles, who proposed this addition to the code panel says that the intention was that when adding a PV system to such a system that both the main breaker and the distribution breaker are to have GFP and be listed for backfeed.
A local utility that desires to donate a PV system to such a school has requested that the circuit breaker manufacturer state that the two circuit breakers are listed for this use. The manufacturer will only state listing is to UL 489 and UL 489 makes no reference to NEC Art 690.64(B)(3), but it does make reference to Art 210.12 that requires the GFP feature.
Has anyone had this requirement come up with an AHJ?
How was it resolved?