On Mon, 31 Aug 2015 18:41:00 +0100, Ash Burton wrote:

On 29/08/2015 19:48, Tough Guy no. 1265 wrote:
On Sat, 29 Aug 2015 19:41:50 +0100, harry
wrote:

On Saturday, 29 August 2015 14:19:08 UTC+1, Tough Guy no. 1265 wrote:
On Sat, 29 Aug 2015 10:06:26 +0100, newshound
wrote:

On 29/08/2015 01:17, wrote:
On Saturday, 29 August 2015 00:13:19 UTC+1, Tough Guy no. 1265
wrote:
My father has said he has a 415V sticker on the feed into his
meter box. From what he's told me there is the normal arrangement of
master fuse, meter, then into the house to the consumer unit. The
house was built in 1985ish and is detached. I've never seen inside
the meterbox myself, only the consumer unit, which looked like a
normal run of the mill row of circuit breakers with one master at the
end, 100A. If there were three phases in the meterbox I'd expect his
description to include a lot more. Now the previous owner did have
an ironwork hobby with "high powered equipment", but he was a very
frugal sort and I doubt he would have got three phases installed if
he didn't absolutely have to - mind you I believe he was the first
owner of the house and designed it himself, so maybe it's just as
cheap to get three phases when building the property? The reason
this has come up is they've just had a 10kW electric shower fitted
(used to run from the hot water tank, but that one
wa
s
old and leaky) and are considering replacing their ageing oil
boiler with an electric one, which the electrician fitting the shower
warned would require a relay to switch off the boiler so it didn't
run at the same time as the shower as he'd run out of juice. When he
saw 415V he was wondering if he infact had more phases available.

clear piccy wanted


NT


Ignore BM, this is the right answer. You could well be right, there
might or might not be 3 phase available. If the current electrician
cannot advise, then you need someone who works on (small) industrial
sites. Sounds like perhaps the 3 phase meter has been taken out and
replaced with a single phase one.

If he (or I but I'm not up there) really wanted to know, it's easy
enough to peek around and use a multimeter. But at the moment it's
just a matter of interest for a possible future electric boiler
installation. I was just wondering if houses ever had more than one
phase installed or if you had to ask for it.

Some houses were supplied with three phases if there was an abnormally
high load or a workshop attached with maybe three phase motors or
welders.
In some cases if there were electric storage heaters. But his was for
quite big houses.

The one previous owner did have an ironwork hobby with large equipment
in the double garage with adjoining workshop.

But quite unusual.
You need to see if there are four wires entering the premises or two.
The cutout will have three fuses if it is a three phase supply.

I'm not there, but I was told what it looked like. There are no extra
fuses or evidence of where they used to be. There is only one cable
coming into the meter box through one hockey stick, and it's the same
width as my single phase one. This leads to the master fuse, then two
wires go through the meter from that, and an earth straight into the
house. If there used to be three phases, it's been very well tidied up.

I think in a roundabout way you have answered your own question.

What you have described in your last paragraph seems to be an ordinary
everyday single phase supply.

You will only know for sure either when you see it yourself or more
likely if your relative enquires for 'load acceptance' for an electric
boiler or similar connection to the DNS (Distribution Network Supplier)
and they check it out.

The 415v sticker could be a remnant from a previous 3 phase supply
installation.

The sticker on the fuse I can understand, mine has it too. But he said there was a sticker on the cable, which suggests he must have a 3 (or 2) phase cable already there, substantially reducing the cost of giving him a 2nd phase.

I don't see that he would find out, would the installer not just assume he has no extra phases available and fit the switch to shut the boiler off while the shower is operating?

--
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