I have two strings that each contain 11 230W panels in series. They are 36V,
8amp panels. Each string has its own DC+,DC-,GND underground conduit covered wiring that is 150 feet long to a PVPowered 5200 inverter with a built in DC disconnect switch.
Can I use black USE-2 #10 for the DC+,DC-,GND wiring? I understand the wiring will need red, black, and green tape, respectively. The GND wire will need the insulation stripped for each panel lay-in-lug. Is this acceptable or does the GND have to be bare #8 wire?
Does each of the two strings need an inline DC fuse at the solar panel
arrays? If so, which do you recommend for each string? The two string arrays are 150 feet from the inverter with built in DC disconnect switch.
Submitted
11 years 10 months ago
Comments
Normally, you would need fuses for the array strings - it always bugged me that the PVP 5200 has a nice integrated disconnect, but no fuses in it.
If your PV source circuits can handle the maximum fault current of the array, then you don't need an OCPD. WIth two circuits, this works, but not with three. Mike Holt clarifies: "You must protect PV source circuits, PV output circuits, inverter output circuits, and equipment per the requirements of Art. 240. However, you do not have to provide overcurrent protection for PV direct-current circuits where the short-circuit currents (Isc) from all sources do not exceed the [690.9(A) Ex] Ampacity of the PV circuit conductors, or Maximum overcurrent device size specified on the PV module nameplate".
Source: http://ecmweb.com/code-basics/nec-rules-alternative-energy-systems-part-1