Technical Support

I've been having voltage issues going out of range now for over 6 months (< 216V - lowest ive seen is 200V and above 253V. Even above 280V for a very very tiny amount of time but we believe this has been resolved by "belt and braces" improvements on the supply - improving the Earth path) although we still regularly see voltages above 260V for a tiny period of time.

I continue to work with the DNO on this.....

We believe the low voltages could be caused by the cable feeding the house and there is potential to upgrade this. However the cause of the high voltage spikes remains to be determined.

Voltage recorders have been on and off a number of times (hence why we have the stats above) including on the main line and in my house. Voltages recorded at my house have been recorded as being higher than those on the main line which suggests there is "push back" from my house (extra voltage being fed back over the neutral). The micro spikes happen following a large amount of demand (eg when I go from the grid to batteries at 10kw and then stop, or when I turn the 8.5kw shower on (and feed it from the batteries) and then stop). Its when the load halts that we see the micro spike.

Its also worth noting that although I am not exporting at the time of the spikes I am limited to a 2KW export due to a lack of capacity on the local grid. There have been checks on the transformer but these haven't shown any issues.

We have also run a test without the solar on for a day (the system was AC isolated) and confirmed these spikes weren't present when the system was AC isolated.

I have a TT earthing system that was reinforced last year and had a reading of 17.17 ohms (on a dry day).

Does anyone have any thoughts on what this might be or the things I can ask a sparky to check?

Thanks in advance.