The inverter has detected that a current that is flowing to earth.

There are a wide ranges of causes for ground faults. Common causes include;

• Positive and Negative cables mixed up
• Damaged cable insulation / Pinched DC cables
• Cables or connectors left on the ground (in puddles)

In most  cases some aspect of the system will require repair or replacement.

1. With the DC switch “OFF,”and the (+) and (-) homeruns landed in terminal blocks/fuseholders, measure and record DC voltage between (+) to ground, and (-) to ground for each home run.
   • If homeruns are being paralleled at the inverter MPPT(s), the homeruns must be isolated prior to troubleshooting.  When opening fuses to isolate strings, the technician must first verify that no current is flowing by using a DC clamp-on ammeter.
   • The measurements should bleed down to a safe level less than 10vDC, and eventually go to zero or close to it. If any of the measurements don’t bleed down, or are greater than 50vDC, the system has a ground fault that should be investigated.
2. If stable voltage higher than 50vDC between either (+) or (-) to ground is measured in Step 1, remove BOTH (+) and (-) homeruns from the terminal blocks/fuseholders on the MPPT, and repeat test.  If voltage to ground is still measured, a ground fault exists outside the inverter that should be investigated via visual inspection or with a megohmmeter (insulation resistance tester or “megger”).
3. If testing does not reveal ground faults from either the isolated DC homeruns nor internal to the inverter, but the inverter still displays a ground fault code, land the homeruns one at a time at the inverter and attempt to start it. If the inverter turns on with a known good DC input in every terminal, then there is no further issue, or the ground fault is intermittent and needs to be troubleshot under the same environmental conditions as when the fault is believed to occur.

This is an inverter driven issue.

Issue Creation

If the inverter sends a single message with this type of alarm in a 24hr period an issue will be created.

Resolution:

If a 24hr period passes with good production, and not futher alarms, the issue will be automatically resolved.