I was recently talking with a solar installer in my area who informed me they were NOT installing an EGC between the array racking/module frames and the combiner box. They are running an EGC from the combiner box down to the inverter and bonding all equipment in-between but they have no EGC bonding the racking/module frames to this EGC in the combiner. The local AHJ is operating under the 2008 NEC and they ARE installing the "additional array grounding" per 690.47(D). They had considered this acceptable as the racking is "grounded" and there was no need to run a ground connection between the array and the combiner box.
I had been taught that there needed to be a DC EGC between the racking and combiner box continuing all the way down to the inverter ALONG with the additional array grounding requirements of 690.47(D). I opened my code book later and found 690.47(D) states "Additional electrodes are not permitted to be used as a substitute for equipment bonding or equipment grounding conductor requirements". This along with 690.43 tells me there MUST be a DC EGC between the racking & module frames connected to the combiner box and continuing down to the inverter.
I'm 99% sure I'm correct and by code there must be an EGC installed between the array and combiner box continuing down to the inverter ALONG WITH the direct connection to ground per 690.47(D), are there any additional code items or documentation that can reinforce my claim?
My major concern is that if there is a ground fault at the array, say some squirrel damage, the current will find a path to ground through the additional electrode required by 690.47(D) and will possibly bypass the GFDI at the inverter, allowing current to continue to flow to ground without popping the GFDI as long as there is light on the PV modules.
Can anyone help me out with this question? I feel like this could be a major safety hazard and they will need to go back to ALL of their jobs to install the EGC between the array and combiner box? Note they are using weebs and lugs at the array properly, it's just this bond between the array and combiner that is missing.
I had been taught that there needed to be a DC EGC between the racking and combiner box continuing all the way down to the inverter ALONG with the additional array grounding requirements of 690.47(D). I opened my code book later and found 690.47(D) states "Additional electrodes are not permitted to be used as a substitute for equipment bonding or equipment grounding conductor requirements". This along with 690.43 tells me there MUST be a DC EGC between the racking & module frames connected to the combiner box and continuing down to the inverter.
I'm 99% sure I'm correct and by code there must be an EGC installed between the array and combiner box continuing down to the inverter ALONG WITH the direct connection to ground per 690.47(D), are there any additional code items or documentation that can reinforce my claim?
My major concern is that if there is a ground fault at the array, say some squirrel damage, the current will find a path to ground through the additional electrode required by 690.47(D) and will possibly bypass the GFDI at the inverter, allowing current to continue to flow to ground without popping the GFDI as long as there is light on the PV modules.
Can anyone help me out with this question? I feel like this could be a major safety hazard and they will need to go back to ALL of their jobs to install the EGC between the array and combiner box? Note they are using weebs and lugs at the array properly, it's just this bond between the array and combiner that is missing.