Centimeter
Member
- Location
- USA
- Occupation
- Farmer
I have a hypothetical question regarding the application of 250.30(A)(1) Exception No. 2 as it relates to renewable energy systems. In a grid-tied micro hydroelectric install, transmission distances are frequently very large and their outputs are commonly rectified and coupled to a solar type inverter/charger, which can be "effectively" isolated, making it a separately derived system. Given the significant transmission distances, it would make sense to deploy 250.30(A)(1) Exception No. 2 in an attempt to drop the number of conductors by getting rid of the EGC.
Take this as an example. Say you have a small three phase 240VAC hydroelectric generator that's 2000ft from its point of use. The cheapest way to transmit that power such a long distance with minimal voltage drop would be to use a full-wave bridge rectifier, which would output 396VDC (1.65*240) and transmit this DC voltage on a two wire path, bonding the negative to ground at the rectifier and at the inverter/charger and putting fused OCPD on only the positive side. Is this a proper application of 250.30(A)(1) Exception No. 2?
Take this as an example. Say you have a small three phase 240VAC hydroelectric generator that's 2000ft from its point of use. The cheapest way to transmit that power such a long distance with minimal voltage drop would be to use a full-wave bridge rectifier, which would output 396VDC (1.65*240) and transmit this DC voltage on a two wire path, bonding the negative to ground at the rectifier and at the inverter/charger and putting fused OCPD on only the positive side. Is this a proper application of 250.30(A)(1) Exception No. 2?
