Hooking up solar panels

[mlnk]

In PV solar installations, some say ground the negative and switch the positive. Some say to ground the positive. Some say to disconnect both neg. and pos. at the disconn switch and run a separate ground wire to a ground rod and use it to ground the boxes and the PV panel frames.

Another idea is to run the wire being disconnected in series through two simultaneous knife blade switches to control the arcing.

 

[mlnk]

I found the answer. At the shut off switch, switch the PLUS, POSITIVE conductor only. Connect the NEGATIVE line to load with an insulated connection. Do not ground the NEG. wire. Ground the box to the grounding system with a separate grounding wire, bare or green. Running the PLUS conductor in series thru two knife blade switches will cut down on arcing but is not standard practice because the switch is rated 600 volts.

 

[BillK-AZ]

Please see NEC Art 690

Please see NEC Art 690

Most say "Do it by the book" (NEC Art 690, etc.). If possible consult the National Electrical Code Handbook and study the simplified circuit diagrams that follow 691.2. None show a 2 pole disconnect. When using safety switches such as Square-D, consult the latest version of the photovoltaic Data Bulletin 3110DB0401R0410 dated 06/2010. The recommended use methods have changed.