GFDI issue

[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.

[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]

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.

[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.

[Sunking]

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?

What kind of meter? Digital?

If you are reading a voltage from ground to either negative of positive polarities is confirmation you have a ground fault. It can be anywhere. Most likely candidate is a chaffed wire and Mr Tree Rat aka squirrel. It can also be an internal fault in a panel.

[sunnybai]

What kind of meter? Digital?

If you are reading a voltage from ground to either negative of positive polarities is confirmation you have a ground fault. It can be anywhere. Most likely candidate is a chaffed wire and Mr Tree Rat aka squirrel. It can also be an internal fault in a panel.

Hi,

Yes, FLUKE series 780 digital.

I agree the meter does not lie. I will get up on the roof now, and start inspecting my way through each module. I will inform you guys of my findings.

What is the procedure for eliminating internal fault in a module? Check negative and positive to frame of module?

Thanks.

[Jairo]

Solar Murals

Good afternoon,

i Am new here..i want to know the difference between the products that you can see in the nex page..

What dou you think is the best??

Thanks very much...

[Naptown]

Good afternoon,

i Am new here..i want to know the difference between the products that you can see in the nex page..

What dou you think is the best??

Thanks very much...

Both will be very low producing items. Not worth the effort or expense as the absorber area is so small.
Could not be used for a direct exchange in a pool as the copper pipes would self destruct in rapid order with the pool chemicals.
The one shown wouldn't be enough to heat a bathtub much less a large swimming pool unless you used like 500 of them.

[Jairo]

the products

But did you see the products en solarmurals.com..
there are three...

[sunnybai]

But did you see the products en solarmurals.com..
there are three...

What's up with high jacking my thread. Please start a new one. This thread is addressing a GFDI issue.

[Sunking]

Yes, FLUKE series 780 digital.

No that is not True, in fact digital meters lie all the time when used on voltages. Fluke makes great meters, very accurate. But all digital meters have one major flaw built into them, very high input impedance in excess of 20 M-Ohms. The problem or error it will give you is Ghost or Phantom voltages where there is none on an open circuit. That is why all Electricians use a meter called a WIGGY which is an ole fashion solenoid volt meter. To trougle shoot what you are looking for will take an analog meter or a Meggar.

[sunnybai]

No that is not True, in fact digital meters lie all the time when used on voltages. Fluke makes great meters, very accurate. But all digital meters have one major flaw built into them, very high input impedance in excess of 20 M-Ohms. The problem or error it will give you is Ghost or Phantom voltages where there is none on an open circuit. That is why all Electricians use a meter called a WIGGY which is an ole fashion solenoid volt meter. To trougle shoot what you are looking for will take an analog meter or a Meggar.

True. I have seen those phantom voltages. Is it possible to meggar a dc pv circuit at night?

[Jairo]

ok thanks..

[inetdog]

True. I have seen those phantom voltages. Is it possible to meggar a dc pv circuit at night?

Do NOT put a megger on the panels. It can/will create a fault where none existed before! If you need to use a megger (megohmmeter) to check the wiring, you will need to disconnect the panels and the inverter first.

To check the panels, one good way is to take each one in turn out of the series string and replace it with a jumper. When the GF goes away, you have found the panel.
Also, if the voltage to ground that you see is a solid one (carefully put a 100K ohm 1 watt resistor in parallel with your meter leads) then the value of the voltage will tell you where along the string the fault is. Do all of this with the GT inverter disconnected from the panels. If the voltage goes away when you disconnect the inverter, then look for an internal problem there.

[Naptown]

Do NOT put a megger on the panels. It can/will create a fault where none existed before! If you need to use a megger (megohmmeter) to check the wiring, you will need to disconnect the panels and the inverter first.

To check the panels, one good way is to take each one in turn out of the series string and replace it with a jumper. When the GF goes away, you have found the panel.
Also, if the voltage to ground that you see is a solid one (carefully put a 100K ohm 1 watt resistor in parallel with your meter leads) then the value of the voltage will tell you where along the string the fault is. Do all of this with the GT inverter disconnected from the panels. If the voltage goes away when you disconnect the inverter, then look for an internal problem there.

Could you explain in further detail what is in red and how this is connected and how it determines where in the string it goes away?