PV Earth Connection

[Leo1]

Is it required, or good practice, to drive a couple ground rods at the PV array disconnect switch, especially is the PV array and disconnect is not close to the utility tie-in ? [Because large arrays make for a large metal target it seems reasonable to reduce the travel of a lightning strike to local ground rods versus having the strike travel solely a couple hundred feet back to the utility earth ground.]

This would be in addition to ground rods at the first utility disconnect switch per NEC, and an equipment grounding conductor that is run with the new conductors from the PV system tie-in disconnect to the PV array and disconnect.

 

[jaggedben]

It is required in the 2008 code. It was not required in the 2005 code or any code before that, or in the 2011 code. Apparently it will be required in the 2014 code because some people thought it was removed in error.

It is generally considered good practice, and is almost always done (in my experience) on ground mounted arrays, and/or at large DC equipment (i.e. combiners and inverters) that are mounted on the ground or on ground mounted arrays.

OTOH, most installers of rooftop residential systems seem to usually forgo it.

Note that even if you don't drive a supplementary ground rod for the PV system, you still need a grounding electrode conductor from the inverter to the premises grounding electrode systems.

 

[Leo1]

It is required in the 2008 code. It was not required in the 2005 code or any code before that, or in the 2011 code. Apparently it will be required in the 2014 code because some people thought it was removed in error.

It is generally considered good practice, and is almost always done (in my experience) on ground mounted arrays, and/or at large DC equipment (i.e. combiners and inverters) that are mounted on the ground or on ground mounted arrays.

OTOH, most installers of rooftop residential systems seem to usually forgo it.

Note that even if you don't drive a supplementary ground rod for the PV system, you still need a grounding electrode conductor from the inverter to the premises grounding electrode systems.

Thank you.