How low may mains voltage be?

Statutory minimum is 216 volts, but you may be getting low volts at the present time coz they're load shedding. When the demand is high, they reduce voltage at the primary substations in two stages, 3% and then 6%. After that it's stage 3, which is rota disconnection! :-(

I'm not sure whether you are saying that it is not permitted to be less than

I do have an axe to grind, of course. My ADSL modem has started to misbehave since next door had their meter moved. For some reason, unknown to me, this did require our supply to be cut off for a period - the houses are linked in some way. The misbehaviour started on the same day as this cut off. Unfortunately I did not measure the voltage beforehand because I did not expect any problem to arise. Of course, there are other possible reasons such as that the modem has developed a fault

The declared statutory voltage these days is 230v +10% -6%, and not

Load shedding voltage reductions may make those figures much worse. In the end, it's better to have dim lights than no lights!

If the problem persists, 'phone your local leccy company and tell them you have low volts. They'll install a recording voltmeter over a period of a few days to check the incoming voltage. It's done at no cost to you.

Sounds like they took the supply down a tapping at the same time, or perhaps moved the house onto a different phase.

Christian.

Load shedding voltage reductions are not allowed to take it below

Was originally going to be 2003. Most countries couldn't meet the deadline and it has been postponed. I believe the earliest enforcement date across EU (or maybe all CENELEC) is now likely to be 2008, although individual countries can adopt earlier if they wish.

No, that's not permitted.

The danger comes from appliances which won't start properly, and might then go on to burn out, such as a synchronous motor which doesn't have enough power to get up to speed.

I didn't say it was permitted, just that load shedding might make it worse!

That makes load shedding impossible then. If the standard voltage tolerances mean that some customers are getting 216V already, then how can they reduce further?

Christian.

Maybe

-- Adam

adamwadsworth@(REMOVETHIS)blueyonder.co.uk

Yes it should, and even more importantly the info on the IEE regs in there is _way_ out of date. I guess these are down to me...

At the back of my mind, I have a suspicion the voltage harmonisation change may never actually happen, a bit like the common EU mains socket.

Within specs. I believe its 230 +10 -20%?

Between 200v and 245v IIRC.

Nope, see other posts 230v +10% -6% curently, may change to 230 +/-

I agree with Andrew that any load shedding should maintain the consumer supply voltage within the range stated above.