PaulHartley2
Member
- Location
- Pennsburg, PA
- Occupation
- Solar Engineer
In a situation where one wants to "oversize" fuses to avoid overheating/tripping (i.e a fused AC Combiner on a hot rooftop in Texas--collecting Inverter output circuits),
do the conductors have to be "oversized" proportionally? I see that NEC ('17) 240.4 (B) allows for the "next higher standard" overcurrent device rating to be used, but is that the greatest ampacity difference permitted (one standard fuse size)?
The current in these circuits is limited by the inverter outputs on the PV side of the fuse, and is connected to the Utility on the other side of the fuses.
In other words, in this type of circuit, can the fuses be rated significantly higher than the conductor ampacity....higer than just the "1 standard device rating size"?
thank you.
Paul Hartley
do the conductors have to be "oversized" proportionally? I see that NEC ('17) 240.4 (B) allows for the "next higher standard" overcurrent device rating to be used, but is that the greatest ampacity difference permitted (one standard fuse size)?
The current in these circuits is limited by the inverter outputs on the PV side of the fuse, and is connected to the Utility on the other side of the fuses.
In other words, in this type of circuit, can the fuses be rated significantly higher than the conductor ampacity....higer than just the "1 standard device rating size"?
thank you.
Paul Hartley