# NEC 690.47 Grounding Electrode System



## jar546 (Nov 26, 2018)

NFPA 70, Article 690.47 requires a grounding electrode system whenever you install a PV ( Photovoltaic) system, otherwise known as solar panels.

Can the existing grounding electrode system of a building be utilized for compliance with NEC 690.47?

Would any of you require a separate grounding electrode system to be installed?

Here is my answer:  Yes the existing system could be installed whether the PV system is AC or DC as long as the existing grounding electrode system is compliant with 250.50 through 250.60 and the GEC (grounding electrode conductor) is compliant with 250.64.


----------



## steveray (Nov 26, 2018)

Agreed....There is/was something about adding a rod if you didn't come off the roof near the service.....


----------



## RJJ (Nov 27, 2018)

ON the surface I would say yes the existing grounding could be used. But 690.47 is saying you need to add an additional system. This to me could be decided by the AHJ. But 690.47 A contains the word shall.


----------



## steveray (Nov 27, 2018)

It says shall have a system, not shall have an added system....


----------



## ICE (Nov 27, 2018)

steveray said:


> Agreed....There is/was something about adding a rod if you didn't come off the roof near the service.....


_690.47(D) Additional Auxiliary Electrodes for Array Grounding. 
A grounding electrode shall be installed in accordance with 250.52 and 250.54 at the location of all ground- and pole-mounted PV arrays and as close as practicable to the location of roof-mounted PV arrays. The electrodes shall be connected directly to the array frame(s) or structure. The dc grounding electrode conductor shall be sized according to 250.166. Additional electrodes are not permitted to be used as a substitute for equipment bonding or equipment grounding conductor requirements. The structure of a ground- or pole-mounted PV array shall be permitted to be considered a grounding electrode if it meets the requirements of 250.52. Roof- mounted PV arrays shall be permitted to use the metal frame of a building or structure if the requirements of 250.52(A)(2) are met._

_Exception No. 1: An array grounding electrode(s) shall not be required where the load served by the array is integral with the array._

_Exception No. 2: An additional array grounding electrode(s) shall not be required if located within 1.8 m (6 ft) of the premises wiring electrode.

_


----------



## RJJ (Nov 28, 2018)

Still think this can be an AHJ call. If it is within 6' not needed. I agree with Steveray on it shall have a system.


----------

