I was looking for an insulation resistance problem (house full of crap and owner insistent on not getting a full rewire done, just replace the problem parts), and I found that the old bathroom fan is switched from the downstairs lighting circuit (bathroom light switch connects to the timer-control of the fan) and is powered by the rear-socket ring.
Looking for insulation problems on the rear socket ring I found the problem to be at the fan, but the weird thing to me is that I found a 200V Direct Current, not AC, between the neutral and earth coming out of the fan. This occurred only when the bathroom light was switched on (just the rear-socket ring being disconnected at the time).
I'm going to be replacing this bathroom fan of course, but I just wondered if anyone could shed some light on why it would be sending a DC voltage back down the neutral, but only when the Line from the lighting circuit is supplying power to the timer.
Looking for insulation problems on the rear socket ring I found the problem to be at the fan, but the weird thing to me is that I found a 200V Direct Current, not AC, between the neutral and earth coming out of the fan. This occurred only when the bathroom light was switched on (just the rear-socket ring being disconnected at the time).
I'm going to be replacing this bathroom fan of course, but I just wondered if anyone could shed some light on why it would be sending a DC voltage back down the neutral, but only when the Line from the lighting circuit is supplying power to the timer.