Mains electrical voltage too high
 

I have measured with a digital voltmeter the mains voltage at home in Spain and got 295 V AC. At the beginning I get a reading of 240V and then it quickly goes up until it stabilises at 295 V.

Is this reading correct?

The AC here is triphasic.

A couple of IC boards for motorized doors, permanently connected to the mains, have recently failed. Perhaps it is related.

I will ask the electricity company as well