Vonze
Member
- Location
- Central New York
Spent a lot of time reading other threads and watching Mike's videos, all helpful, but still have some uncertainty (newbie at PV). Have (2) small arrays, 10 ft. apart with (5) 280W modules each, possibly add a 3rd in future, enphase M250 microinverters with integrated ground. 1) Sizing conductor: 15 x 1.0A (AC output rating at 240 V) x 1.25 = 18.8A @ 75C @ 100 ft. => 10 AWG. (1.9% Vdrop or "Vrise" if you read enphase literature) for L1, L2, N. Will drop to 12 AWG to split to each of the (2 or future 3) arrays. If there's something worng so far, I'd appreciate a heads up, like could N be smaller all the way? 2) Plan on (1) combined disco at arrays (I know it's optional) and at house near utility meter (no line of sight), then 20-A 2-pole backfeed breaker. Don't think discos need to be fused? 3) These microinverters need no DC GEC, have only EGC in wiring harness. Intend to bring that back to AC load center gound lug. Will use grounding clamps from modules to rails and grounding lugs on rails (Ironridge says only need to pick up 1 of the 2 rails, but may just do both). Both array and inverter ECG's bond together per: http://enphase.com/global/files/Enp...d-Ungrounded-Arrays_Whitepaper_English_NA.pdf, page 3. Everything I've read indicates the array EGC should be no. 6 bare. My real Q is the size of the combined EGC back to the main panel? Can't seem to get a handle on that. If 10 AWG (or smaller?), is it okay to bond the no. 6 array ECG to it? BTW, I already ran a 1" PVC buried conduit, hope I'm not in trouble there. 4) Then there are my metal supports (not Ironridge pipe system, but my own 2 position tilt design) anchored to concrete piers. What should I do for those with repect to grounding? Nothing required? Supports are comprised of many pieces: uprights with a pair of yokes, tilt arms, bracing and brackets and bolts. It would be very hard to bond ground straps to every single piece. Thank-you and God bless.