Enecsys micro inverter installation problem

Enecsys micro inverters SMI-D360W-72
Hyundai panels HiS-S335TI

We are putting in a ground-mounted PV system (4x3 in three arrays) and are at the point where we are installing our panels and Enecsys micro inverters. We have been doing this ourselves under an electrician. For some reason the green wire is hot, and that doesn't seem right. Has anyone else had this problem?
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  • EstragonEstragon Registered Users Posts: 1,616 ✭✭✭✭
    IMHO, exposed wiring should never get hot. It suggests the wire is carrying too much current, and risks becoming a fire hazard. You may want to stop the installation (with panels unconnected) until you can get the electrician to troubleshoot.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • BB.BB. Super Moderators Posts: 26,872 admin
    Go back to your home's main panel and check voltages against (metal) water pipe).

    It does happen where the original electrician got the L1/L2/Neutral mixed up and grounded one of the Lx leads (besides measuring voltage, using a Clamp on Amp/Current meter on each lead to see if you are carrying significant current through your ground wire, or "unbalanced current from the utility down drop--I.e., clamp all through wires from the utility--The total current should add up to near zero amps--certainly less than a couple of amps worst case).

    If there is a short between Lx and ground, the typical current will be around (120 VAC/25 Ohm "worst case" ground rod resistance to earth=) ~4.8 to ~10 amps or so... Not enough to blow any breakers or overheat any wiring--But still a significant "current leak".

    Another possibility is that you have a short between Lx and your metal solar panel rack. That can energize the rack with respect to ground. Measuring with a volt/current clamp meter, as above, should help answer your question.

    There are also other ways that this can happen. A miss wiring anywhere in the neighborhood could cause a similar issue (nearby neighbor or power pole/transformer miss wired between Lx and Neutral/ground bond).

    Sometimes, a DMM can pickup stray amounts of current/static charges between ground and ungrounded metal structures because the meters have >1,000,000 Ohms of resistance and provide very little current loading.

    A simple diagnostic tool is to get a 40-100 Watt 120 VAC filament lamp and screw it into a utility socket. Attach wire and alligator clips to the socket. And, for example, connect the lamp from "hot" metal to a ground rod (or partially buried metal plate, ground made wet with a bucket of water--if dry). The lamp will "short" any small amounts of current and give you a more accurate voltage reading--And the lamp will glow if there is significant current flow (but keep current flow safe--If you did accidentally connect Lx and Ground together).

    You are correct to be worried... Any miss wiring that makes a metal structure "hot" with respect to ground can easily electrocute somebody (tall weeds/rain/mist a bad mix...)

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • RobertTRobertT Registered Users Posts: 2
    Thank you for you help, I was able to find the problem and everything appears to be working now.

    TR
  • BB.BB. Super Moderators Posts: 26,872 admin
    edited November 26 #5
    Robert,

    What was the problem, if you do not mind.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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