ESolar
Senior Member
- Location
- Eureka, CA Humboldt County
- Occupation
- Electrician/Contractor
Roof top solar array: Enphase microinverters kicking out AC (two conductor). Solid copper EGC bonded to racks. EMT sleeve runs from East to West side of roof and between strings on west side. EMT does not terminate in a box (i.e., open ends). Obviously the EMT runs must be bonded to the EGC. Solar PV wires also require splicing in JBoxes so that sections of large strings are run in parallel. The plan is to run all EGC solid copper to one jbox with a pass-through into attic. To avoid additional holes in roof, I am using EMT clamps attached to the solar racking. The JBOXs for splicing solar wire are polystyrene. I plan on attaching them with either plastic or metal screws to aluminum brackets, with brackets bonded to the solar racks with the approved mounting screws for the microinverters. Here are my questions:
EGC Questions:
1. Can multiple EGCs solid copper wires terminate in jbox/pass-through to a lug with one solid copper wire from that lug running passed through to combiner box in attic? (I guess this would be referred to as a reversible spice in a jbox)
2. Do I need to bond the EGC to an EMT sleeve on both ends, or can I just bond it to one end?
3. Can I use an insulated green EGC and just strip the insulation where bonding?
4. Do I have to, and can I, run the EGC (bare or insulated) inside the EMT with the PV AC wire?
5. The bonding bushing for the EMT has a lug on the outside of the bushing. If I run the EGC inside the EMT, after it goes through the ground lug of the bushing, then I will have to loop it backwards to get into the EMT tubing. Is there a better/standard way to address this (e.g., it would be nice if the lug were in line with the tube opening)? Or does one simply loop it back through?
6. Does a hand made aluminum bracket attached with approved mounting screws satisfy bonding requirements.
PV splicing JBOX Questions:
1. No EGC needed? (its plastic)
2. If I attach the polystyrene jbox to the aluminum bracket metal screws, then those screws would be bonded to the aluminum bracket (in theory), and the bracket is bonded to the rack. In addition, the boxes have a plastic plug to seal the mounting holes such that there is no exposed metal inside the box, even when using metal screws. Are there any additional bonding requirements other than the bracket/EGC bonding if I use metal screws to attached a plastic JBox?
Also - these are NEMA4 JBOXs. It seems reasonable that I should create weep holes in case they leak. Otherwise, in the very unlikely event that they take on water, it has nowhere to go. Thoughts on this?
EGC Questions:
1. Can multiple EGCs solid copper wires terminate in jbox/pass-through to a lug with one solid copper wire from that lug running passed through to combiner box in attic? (I guess this would be referred to as a reversible spice in a jbox)
2. Do I need to bond the EGC to an EMT sleeve on both ends, or can I just bond it to one end?
3. Can I use an insulated green EGC and just strip the insulation where bonding?
4. Do I have to, and can I, run the EGC (bare or insulated) inside the EMT with the PV AC wire?
5. The bonding bushing for the EMT has a lug on the outside of the bushing. If I run the EGC inside the EMT, after it goes through the ground lug of the bushing, then I will have to loop it backwards to get into the EMT tubing. Is there a better/standard way to address this (e.g., it would be nice if the lug were in line with the tube opening)? Or does one simply loop it back through?
6. Does a hand made aluminum bracket attached with approved mounting screws satisfy bonding requirements.
PV splicing JBOX Questions:
1. No EGC needed? (its plastic)
2. If I attach the polystyrene jbox to the aluminum bracket metal screws, then those screws would be bonded to the aluminum bracket (in theory), and the bracket is bonded to the rack. In addition, the boxes have a plastic plug to seal the mounting holes such that there is no exposed metal inside the box, even when using metal screws. Are there any additional bonding requirements other than the bracket/EGC bonding if I use metal screws to attached a plastic JBox?
Also - these are NEMA4 JBOXs. It seems reasonable that I should create weep holes in case they leak. Otherwise, in the very unlikely event that they take on water, it has nowhere to go. Thoughts on this?