GFDI issue

[Naptown]

Check all the wiring to make sure nothing is chaffed chewed on etc and shorting out. This is probably the #1 cause of ground faults.

[sunnybai]

Just where in the circuit is this GFDI "fuse"? Unlike a GFCI breaker, a fuse will require a substantial current to trip, and indicates a problem somewhere.
In a conventional electrical circuit, the electrician would disconnect all active devices (loads and sources) and then use a megger (a high voltage ohmmeter basically) to check the insulation resistance of the wiring. Since your ground fault (if there is one) may actually be inside a panel, that is not a good option for you.

Also, with a GT inverter you do not have the option of shutting down the load to see whether the fault trip results from the voltage from the panels or the AC output being generated.

I hope someone else has more concrete advice for you based on the specific GT inverter you are using.

PS: Voltage to where "on the return side of the DC?" If it is ungrounded, you should not have any consistent reading to ground on either + or - sides of the array.

Hi,

The GFDI fuse(1A) is located in the Inverter(2500xi kaco). It senses the DC circuit.

It is ungrounded. I agree there shouldn't be any voltage on the - side of the circuit, but I am reading a voltage with my multimeter. This tells me there is leakage somewhere (is this correct?), I guess I have to pull each module?

The fact that the fuse does not blow under low light conditions makes me suspicious of a faulty module? If I had a consistent ground fault, I assume the fuse would blow instantly.

Thanks again for your assistance.

[inetdog]

Hi I have a string of 12 modules(230W). When the array reaches 1800W the GFDI fuse blows on the GT inverter. I have visually inspected the wiring seems ok. What type of voltage should I be reading on the return side of the DC? What is the best way to troubleshoot this fault?

Thank you in advance for your input.

Just where in the circuit is this GFDI "fuse"? Unlike a GFCI breaker, a fuse will require a substantial current to trip, and indicates a problem somewhere.
In a conventional electrical circuit, the electrician would disconnect all active devices (loads and sources) and then use a megger (a high voltage ohmmeter basically) to check the insulation resistance of the wiring. Since your ground fault (if there is one) may actually be inside a panel, that is not a good option for you.

Also, with a GT inverter you do not have the option of shutting down the load to see whether the fault trip results from the voltage from the panels or the AC output being generated.

I hope someone else has more concrete advice for you based on the specific GT inverter you are using.

PS: Voltage to where "on the return side of the DC?" If it is ungrounded, you should not have any consistent reading to ground on either + or - sides of the array.

[sunnybai]

Hi I have a string of 12 modules(230W). When the array reaches 1800W the GFDI fuse blows on the GT inverter. I have visually inspected the wiring seems ok. What type of voltage should I be reading on the return side of the DC? What is the best way to troubleshoot this fault?

Thank you in advance for your input.