"Andrew Thelwell" wrote in message
oups.com...
Hi,

Note: This post is talking about UK (220-240V mains supply)

My girlfriend and I recently moved into our newly-purchased house. We
wanted to get the electric meter changed but when the guy came out to
do so, he reported a live reading on the neutral block in our meter
box. This was potentially dangerous, he said, and he called out the
mains engineers. They investigated and couldn't replicate the problem.
They asked if we'd experienced any problems in the house and we hadn't.

He's a cowboy trying to rip you off. A new house should have an inspection
certificate, so ask for a copy, then contact the person that arranged your
survey and complain. You can't have both live and neutral on a neutral
block or your main fuse would blow. What he has measured is the voltage
between neutral and earth. If you have fluorescent lights this sometimes
happens. It can happen if you have a faulty TV or video.

Since then we've had three occurrences of the RCDs in our fuse box
tripping. I today bought a standard socket tester and tested every
socket in the house. I've found the culprit to be the mains outlet in
our spare bedroom, which appears to be incorrectly wired, showing a
live/neutral reverse on the tester.

That would not cause a problem anywhere else, but should have been checked
before you bought the house. The socket is not connected to anything else
unless it is in a loop. Just rewire it or get the seller to correct it.

My questions, then...

1) Would this explain both the apparent live neutral reading in our
main meter box and the tripping of the RCDs? I always thought RCDs were
only concerned with earthing faults, not live/neutral reverse polarity
type problems

Depending how it is wired and what you use might make one circuit breaker
trip.

2) I've been using the sockets in that room with no real probles apart
from the trips. All equipment (TV, XBox, amplifier, phone charger) have
worked OK thus far. Is the socket likely to be causing any harm?

It will not cause harm, but you will be switching the neutral instead of the
live.

3) Is this potentially dangerous?

Not unless you take something apart and think it is switched off !

4) Is getting this fixed a big (and ergo, expensive) job?

No, get a screwdriver - open the socket after witching the mains off and
make sure that the L terminal is going to RED or BROWN wires and N terminal
to BLACK or BLUE. If they are correct then check inside the consumer unit -
then check for any junction boxes.


Your help would be much appreciated as I've had surprising difficult
finding any info about this on the web.

Many thanks

Andy

There are lots of cowboys about, so don't be conned in to buying new
consumer units or having your home rewired. Don't bother checking for
reputable trades people with trading standards either - they don't bother
checking them out and are not allowed to tell the public even if a company
does have a bad record!