Re: [Hampshire] [OT] PCs blowing domestic fuses

Rob Malpass wrote:
> My father-in-law has just come up with another gem - and as it's been
> quite some time since I've done any electronics, I thought I'd ask for
> confirmation of my suspicions.
>
> Apparently he switched on his PC and it promptly blew a circuit breaker
> back at his house's distribution box! Now as I recall, P=IV. I=13
> Amps, V=240 so unless his power supply is something like 3000 Watts
> (enough for a kettle or electric fire), there isn't much chance of the
> culprit being his PC. There isn't much else in the room (or on the
> circuit) he uses - nothing like a kettle or electric fire anyway!

Circuit breakers don't just trip on an overload, they trip if there is
an imbalance in the current flowing into and out of the circuit.

> So I've suggested he:
> a) plugs a kettle into the same wall socket - to see if it trips the
> circuit breaker.
> b) moves the computer downstairs - to see if he can get it to work.
>
> Any other obvious things I can try? Has anyone else had a situation
> where a PC has blown a domestic fuse?

Has he tried just plugging the PC back in and trying it again? If it
continually trips the breaker then I'd suspect a problem in the PSU.

This is slightly convoluted story; I had a sudden power cut, the whole
street was out. I duly unplugged my sensitive equipment and waited for
the power to come back. When the supply was restored I plugged in my PC
and there was a burning smell and a wisp of smoke from the PSU on the
PC. Then the fuse blew and my heart restarted.... Needless to say it
had the PSU removed and replaced.

It seems that the power cut had caused the PSU to fail in some way,
which then caused a short circuit, hence the fuse blowing.

Hope this helps.