Wire & Cable Information

Solar Array Cables

A, B

Solar Panel to Panel to PSPV combiner box

This wire can be one of three general types:
1. USE-2 single conductor wire, two from each panel with MC connectors to match the MC connectors on the panels. A trick is to buy a single MC Extension Cable and cut it in half to wire into the PSPV. Buy one that about twice as long as the distance from the last panel to the PSPV.

2. Two conductor jacketed THHN or THWN cable. I usually use 10ga from panel to panel. It depends on the distance from the last panel to the PSPV, usually 10ga or 8ga. Be sure to use a strain relief such as the one pictured.

3. Two individual THHN or THWN cables in the metallic or non metallic conduit. Same Wire Size rules apply as 2. above.

Grounding Panels

A ground wire needs to be installed:
1. along each panel to the PSPV, preferably using a Grounding Lug similar to the one pictured at the right. I generally use 8 or 10ga, please check the code (you may need to use 6ga for its resistance to damage).
2. from the PSPV to a ground rod driven into the ground near the Solar Array. I generally use minimum 6 ga wire (or same size as 3.), please check the code for details.
3. from the PSPV to the PS2DC ground bus connection. I use the same gauge as the positive/negative conductors.

This PSPV Photo shows the ground wires mentioned above. Plus it shows a Delta LA302-DC Lightning Arrestor. Learn More about Delta Lightning Arrestors.

Solar Array to PS2DC (Homerun cables)

C

PSPV (the Array) to PS2DC

From the PSPV (solar array) to the PS2DC disconnect, the cable size will depend on the:
1. distance from array to the PS2
2. the voltage the array generates
3. the current the array generates
I sometimes use two circuits of conductors (2 positive, 2 negative) because a roll of wire is cheaper than by-the-foot price for the larger gauge, but the voltage loss is same or lower for the two wires together.

Battery Cables

D

Battery To Inverter Connections

The Battery to Inverter connections should generally be 4/0 for 24 volt systems and 2/0 for 48 volt systems. It there is any doubt, just use 4/0 for every battery connection. D, E and F are generally the same type cable, but different lengths. Custom cut lengths are available, but standard lengths are simpler. Learn about making Battery Cables here or if you need custom length cables, contact me.

Common distance is 5 to 10 feet.

E, F

Battery to Battery Connections

It is recommended to use 2/0 or 4/0 cable to interconnect batteries. The best brand cable is Cobra X-flex wire, other brands are also excellent.

E. Common distance for battery to battery is 12 inches.
F. Common distance from PS2DC to inverter: Best to custom make this cable, but 36" pair work ok. Learn about making Battery Cables here or if you need custom length cables, contact me.