electro7
Senior Member
- Location
- Northern CA, US
- Occupation
- Electrician, Solar and Electrical Contractor
Hi,
We are troubleshooting an Advanced Energy 500NX inverter. It has a PV positive hot, PV positive neutral, PV negative hot and PV negative neutral- Bi polar array. The inverter is throwing an intermittent fault. We thought originally it was a ground fault in an array since one of the ground fault fuses in the inverter was blown. I was told to measure voltage with the ground fault fuses out to float the array from all four conductors in free air to ground. There are 5 "zones" for each "side" of the bi polar arrays. So there were actually 10 conductors I took readings on, only the PV positive side. My readings were around 60 volts to ground on the neutrals and 320 volts to ground from the hots to ground. I was told they should be equal. A co-worker went out today because another fault was thrown but neither ground fault fuse was blown. He tested by turning the inverter off, pulling the ground fault fuses, turning off all the combiner boxes associated with the inverter and measuring voltage to ground from the hots to ground and the neutrals to ground at the combiner boxes. He found the same thing 60V to ground on grounded, neutral conductors and 170V from ungrounded, hots to ground and bleeds off. Advanced energy is thinking there is a ground fault. I am thinking there is a malfunction in the inverter. The files downloaded from the inverter show array voltage at 750 volts then when the fault is thrown it shows a spike up into the 950 volts for the array. Any thoughts on what it could be?
We are troubleshooting an Advanced Energy 500NX inverter. It has a PV positive hot, PV positive neutral, PV negative hot and PV negative neutral- Bi polar array. The inverter is throwing an intermittent fault. We thought originally it was a ground fault in an array since one of the ground fault fuses in the inverter was blown. I was told to measure voltage with the ground fault fuses out to float the array from all four conductors in free air to ground. There are 5 "zones" for each "side" of the bi polar arrays. So there were actually 10 conductors I took readings on, only the PV positive side. My readings were around 60 volts to ground on the neutrals and 320 volts to ground from the hots to ground. I was told they should be equal. A co-worker went out today because another fault was thrown but neither ground fault fuse was blown. He tested by turning the inverter off, pulling the ground fault fuses, turning off all the combiner boxes associated with the inverter and measuring voltage to ground from the hots to ground and the neutrals to ground at the combiner boxes. He found the same thing 60V to ground on grounded, neutral conductors and 170V from ungrounded, hots to ground and bleeds off. Advanced energy is thinking there is a ground fault. I am thinking there is a malfunction in the inverter. The files downloaded from the inverter show array voltage at 750 volts then when the fault is thrown it shows a spike up into the 950 volts for the array. Any thoughts on what it could be?