negative grid voltage spike?

[ddmbr]

I've got 3 EASUN 5.6kw in parallel in an off grid config with grid backup. I only noticed later in the afternoon but there was a massive momentary grid spike logged by solar assistant at approx 4.45 am. In addition some other readings were off the scale such as inverter temp of 300C. Other than that no errors on the inverters etc. Any thoughts?

 

[mikefitz]

Grid fault in your area,

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powercuts.nationalgrid.co.uk

 

[ddmbr]

Thanks Mike, that does make sense.

 

[ddmbr]

I'm re-opening this as I think these have to be phantom readings.

I have 3 parallel inverters with a 40A breaker in each. To reach 58k at 230V would require an output current of 252A which is 84A each. As this was 8pm it is dark outside so little to no solar which means it could only come from the batteries. I have 6 x 5KWh with a max output current of 102A for 15 seconds. To provide 58KW would need a draw from all 6 circa 1000A which would be 172A each. Im certain that would have blown the 250A fuse between the batteries and the inverter plus the heat itself to create that kind of power I would expect internal component damage. Looking at the inverter recorded battery voltages they are wildly inaccurate on all 3 also. I'm no expert of course, happy to be told I'm an idiot. My main concern is safety. Anyone have any ideas or experience of this?