"Julian" wrote in message
...

"John Rumm" wrote in message
...
Julian wrote:

Quick question for the electrical boffins:

AIUI mains voltage is now 230 volts -6% +10%. ie 216 to 253 -
correct or
rubbish?

That is the specification. In reality much of the UK supply is
still at
240V like it always was since that meets the above spec.

My question is how is it measured? I've stuck my AVO across the
incomers
to the main fuse box, and can get the voltage down to about 216v
if I
switch on about 6.5KWs of electrical load on the property -
without any
substantial load the voltage is nearer 250V. So, under what load
condition is the voltage measured?

Are you out in the sticks with a long overhead supply?

It sounds as if your supply has a rather higher than desireable
impedance.
If you have a 60A supply and are dropping 34V on a load of only
27A that
would suggest you are going to be down to 175V on full load, which
is way
too low, and likely to cause problems.

I think I would be tempted to contact the supplier about that.

Thanks to all the replies. You've made me more sure now that I do
have a
problem because I'm having difficulty welding with large rods, in my
old
house with the same equipment it was fine.

Regarding my supply, I have a transformer up the top of a pole in my
garden,
this is a small jobby and supplies my next door neighbour too, but
that's
all it does. Here it is:
http://freespace.virgin.net/julian.s...ransformer.JPG The other
wires are
telephone. There's a lot of very old looking wires up there, I guess
some
connections may have gone high resistance?

Regarding a true RMS meter, I don't have such an animal, but I'll
see if I
can borrow one. My meter is a cheap Clarke thing.

I'm going to repeat my tests, just to make sure of myself and then
contact
the supplier. What is full rated load, I note that I have a 100amp
supplier
fuse?

Thanks again.

Julian.



100a x 230v (nominal) = 23kW

Be aware when my company fuse blew the other month, although it was in
a 100amp carrier, the fuse itself was only 60 amps. Chap from EDF was
happy to put a 100amp in having drunk his tea G Lots of big motor
with high starting current in my home workshop, as I explained to him.

AWEM