One of our clients recently reported a potential solar inverter fault which meant that the mains supply to their solar inverter would intermittently trip. This had reached the stage where the main RCD would not reset unless the Solar PV inverter was switched off. The client also reported that their solar PV system was underperforming when compared to their neighbour’s equivalent system on a similar pitch and elevation.
How we diagnosed and fixed this suspected solar inverter fault
Power One PVI3.6 OUTD Solar Inverter Tripping Mains Supply
We attended the site to carry out earth leakage current checks on the side of the consumer unit which was protected by a 30mA RCD which supplied the Power One PVI3.6 Solar Inverter.
The leakage current was monitored with all circuits other than the inverter supply connected. It was found that due to other high earth leakage electronic devices being supplied on that side of the consumer unit the inverter leakage current added just enough earth leakage current to trip the RCD. To resolve this the inverter supply was moved to the none protected side of the consumer unit. When power was restored to the inverter it was found to be in full working order.
Under performing Power One PVI3.6 OUTD inverter
We carried out a full solar pv system check where no faults were identified. We explained to our client that a possible cause for the inverters apparent lack of performance may be due to the inverters over voltage setting being 253 Volts and their neighbour’s system would probably be higher, 263/4 Volts as their neighbour’s system was installed after theirs and would probably have a higher over voltage setting.
Unfortunately, the Power One inverter over voltage settings could not be altered as can be done with some of the SMA inverters for instance. We requested our client monitor the system carefully and we would re-attend if this became an unacceptable problem in the future.
Other issues found
Whilst on site it was noted that the installer of the system had left single insulated cables exposed where a cable had been spliced to connect the current transformers of a third-party Watson monitoring system (see the image below).
Issues with your Solar PV System?
If you are experiencing issues with your Solar PV system call C Gascoigne on 01509 341971 or get in touch online here and a member of our experienced solar PV maintenance and repairs team will advise on the best course of action.