I have a weird problem with the electricity in my house. The house has a three phase municipal supply 400/230V WYE electrical system. The house is old and already I have had problems with water causing short circuits. Before anyone crucifies me, I am going to leave this house in a month or two and leave all the problems to the owner to fix before he rents it out again. But it is unlikely he will fix the current problem so I have to repair it myself to enjoy the luxury of electricity for the last days I will be living here. I am quite capable, but I just need a memory jog. The house is so badly wired that I have been unable to determine how they distributed the loads.
So, during the present rainy season, all of a sudden on two phases I get 270 volts, the third phase is 230V (Phase to neutral). If I plug in a high load appliance such as a kettle on any phase, the other phases go ballistic, i.e. they either drop to below 200V or climb to 280V.
A while back I was a facilty supervisor and one problem we encontered was a failed neutral line on a WYE system. This puts 400V across all three phases (P-N). So I'm wondering if water has somehow gotten into the cables and caused this? It's obviously not a complete neutral disconnect otherwise I would measure 400V P-N on all of them.