Hi Forum,
I have an issue that I cannot figure out. I am running from the roof the PV+/- and the grounding wire through the same metallic flexible conduit. The distance is about 20m. PV+/- wires are 6mmp and the grounding wire is 10mmp. The other day I was doing some re-arrangement of the cabling and I've discovered a small spark when connecting the grounding wire to the earthing rods. For the whole house (including the inverter) I have one earthing. I've measured the current and it was about 1A, so not negligible. I've measured the continuity between the PV+/- and the grounding wire and there's none. Also it's not a ground fault of the panels, there are zero volts in between the + or - and the ground wire. This only happens when the inverter output is on. If the inverter output is off, yet it's mppt is running, there is no spark, no current going through.
I've ran just for testing an additional ground wire, yet this time it was outside the metallic conduit under the same conditions and there is no current over it, only for the wire inside the metallic conduit. Could this be caused by induction? I am not keen on taking the whole conduit apart and replacing it with PVC uv resistant tubing.
The inverter is an Easun IGrid SV 4. I have two units, one brand new which I've tested (currently not used), the phenomena is the same. Some colleagues on another forum suggested this may be the anti PID function. I guess there is always some current going through the mppt and the PV+/- wires as there is no galvanic insulation in the inverter. I've measured the PV+/- ports of the inverter with the pannels disconnected and I get the battery voltage (50V). However, I cannot explain the current in the grounding wire: at night (probably the panels are producing something as there is street lighting or there is the battery voltage on the PV+/- cables going to the roof), if I have that grounding cable disconnected from the earthing rods yet everything else connected, as soon as I touch the cable to the earthing rods I get the small spark. I guess it's induction and I should have not ran the grounding wire in a metallic conduit, maybe not even the PV+/- cables. What do you think? Thank you in advance!
I have an issue that I cannot figure out. I am running from the roof the PV+/- and the grounding wire through the same metallic flexible conduit. The distance is about 20m. PV+/- wires are 6mmp and the grounding wire is 10mmp. The other day I was doing some re-arrangement of the cabling and I've discovered a small spark when connecting the grounding wire to the earthing rods. For the whole house (including the inverter) I have one earthing. I've measured the current and it was about 1A, so not negligible. I've measured the continuity between the PV+/- and the grounding wire and there's none. Also it's not a ground fault of the panels, there are zero volts in between the + or - and the ground wire. This only happens when the inverter output is on. If the inverter output is off, yet it's mppt is running, there is no spark, no current going through.
I've ran just for testing an additional ground wire, yet this time it was outside the metallic conduit under the same conditions and there is no current over it, only for the wire inside the metallic conduit. Could this be caused by induction? I am not keen on taking the whole conduit apart and replacing it with PVC uv resistant tubing.
The inverter is an Easun IGrid SV 4. I have two units, one brand new which I've tested (currently not used), the phenomena is the same. Some colleagues on another forum suggested this may be the anti PID function. I guess there is always some current going through the mppt and the PV+/- wires as there is no galvanic insulation in the inverter. I've measured the PV+/- ports of the inverter with the pannels disconnected and I get the battery voltage (50V). However, I cannot explain the current in the grounding wire: at night (probably the panels are producing something as there is street lighting or there is the battery voltage on the PV+/- cables going to the roof), if I have that grounding cable disconnected from the earthing rods yet everything else connected, as soon as I touch the cable to the earthing rods I get the small spark. I guess it's induction and I should have not ran the grounding wire in a metallic conduit, maybe not even the PV+/- cables. What do you think? Thank you in advance!
