I have just moved a small (1.7kW) storage heater to a temporary location
(next to my desk!) where I plan on using it until March-ish. We are on E7,
and downstairs (where the heater now is) has separate fuseboards to
upstairs. I could wire it into the off peak fuseboard (which feeds just the
lounge storage heater), but it would be easier for me to plug it into the
mains (on a timer) on account of its temporary status.

Other items that run off the downstairs mains overnight are the immersion,
the washing machine and the tumble dryer. I tend to have these come on
about 5am so they're all nice and fresh for me in the morning. I imagine
the storage heater would have done most of its warming up by then and would
be cycling on and off according to its thermostat.

On balance, would it be ok to plug it into the mains, or do I really want to
be hard wiring a new spur into the off-peak board?

Many thanks,
xena

In an earlier contribution to this discussion,
xena wrote:

I have just moved a small (1.7kW) storage heater to a temporary
location (next to my desk!) where I plan on using it until March-ish.
We are on E7, and downstairs (where the heater now is) has separate
fuseboards to upstairs. I could wire it into the off peak fuseboard
(which feeds just the lounge storage heater), but it would be easier
for me to plug it into the mains (on a timer) on account of its
temporary status.
Other items that run off the downstairs mains overnight are the
immersion, the washing machine and the tumble dryer. I tend to have
these come on about 5am so they're all nice and fresh for me in the
morning. I imagine the storage heater would have done most of its
warming up by then and would be cycling on and off according to its
thermostat.
On balance, would it be ok to plug it into the mains, or do I really
want to be hard wiring a new spur into the off-peak board?

Many thanks,
xena

Are you posing this as a technical question - or one of economics?

From a technical point of view, the heater will work perfectly well if
connected into the ring main.

However, it will cost considerably more to run - since it is using
electricity at peak price rather than off-peak price.

If you assume that it will use an average of (say) 5kWh** per night for 60
nights = 300 kWh in total - you can multiply this by the difference in unit
price of the two tariffs in order to work out how much extra it will cost
you. Then compare that with the cost/hassle of providing an off-peak supply
for it - and decide which solution suits you better.

** Substitute your own assumption. Worst case - if the heater was running
flat out for the whole off-peak period - would be 7 x 1.7 = 11.9 kWh per
night - but it will of course be going on and off on its thermostat
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

"Roger Mills" wrote in message
...

However, it will cost considerably more to run - since it is using
electricity at peak price rather than off-peak price.

Unless I am *extremely* mistaken, all my leccy switches over to cheap rate
at 12.30am and back onto peak rate at 7.30am.
I have one meter outside that shows "normal" and "low" readings, and this is
controlled by a teleswitch.

"xena" wrote in message
...
"Roger Mills" wrote in message
...

However, it will cost considerably more to run - since it is using
electricity at peak price rather than off-peak price.

Unless I am *extremely* mistaken, all my leccy switches over to cheap rate
at 12.30am and back onto peak rate at 7.30am.
I have one meter outside that shows "normal" and "low" readings, and this
is controlled by a teleswitch.

Sorry to follow up my own post, but my immersion also runs off the mains (on
a timer) so I certainly hope that goes on my cheap rate! I'm sure it does,
as our leccy consumption split over the last 2 years has been 62% off peak /
38% peak.

After serious thinking Roger Mills wrote :
However, it will cost considerably more to run - since it is using
electricity at peak price rather than off-peak price.

Er, well no.

The entire system switches over to off-peak, or rather just the meter
does. Two dials in the meter which record off-peak and peak consumption
the times of which are defined by a time clock, therefore any
consumption during off-peak periods will be charged at off-peak rates.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

In an earlier contribution to this discussion,
Harry Bloomfield wrote:

After serious thinking Roger Mills wrote :
However, it will cost considerably more to run - since it is using
electricity at peak price rather than off-peak price.

Er, well no.

The entire system switches over to off-peak, or rather just the meter
does. Two dials in the meter which record off-peak and peak
consumption the times of which are defined by a time clock, therefore
any consumption during off-peak periods will be charged at off-peak
rates.

If that is truly the case, it doesn't matter *how* it's connected - but the
OP mentioned having a separate off-peak fuse board so I assumed (seemingly
wrongly) that there was a separate meter and a timer which only made the
off-peak part live for the designated seven hours.

My f-i-l's bungalow certainly used to be like that. Maybe the OP has got
what used to be called a "White Meter"?
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

Roger Mills wrote:

My f-i-l's bungalow certainly used to be like that. Maybe the OP has got
what used to be called a "White Meter"?

My guess is the OP probably has something like this setup (although
perhaps without the prehistoric CU to the right!):

http://www.internode.co.uk/e7/


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:

Roger Mills wrote:

My f-i-l's bungalow certainly used to be like that. Maybe the OP
has got what used to be called a "White Meter"?

My guess is the OP probably has something like this setup (although
perhaps without the prehistoric CU to the right!):

http://www.internode.co.uk/e7/

No, Two counters (low & Normal) on the meter and separate 24hr
mechanical timer with clock work spring which switch over the meter and
switch on the E7 cables

--
zaax

Roger Mills wrote :
If that is truly the case, it doesn't matter *how* it's connected - but the
OP mentioned having a separate off-peak fuse board

The separate fuse board is simply to make the installation easier. A
time clock sets the on/off times and that (usually) operates a
contactor, the contactor then feeds a separate fuse board. So nothing
at all to stop you using separate clocks, one per heater, other than
the inconvenience of checking/setting several clocks.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Harry Bloomfield wrote:

After serious thinking Roger Mills wrote :

However, it will cost considerably more to run - since it is using
electricity at peak price rather than off-peak price.


Er, well no.

The entire system switches over to off-peak, or rather just the meter
does. Two dials in the meter which record off-peak and peak consumption
the times of which are defined by a time clock, therefore any
consumption during off-peak periods will be charged at off-peak rates.

This is my understanding also. The extra consumer unit is just there to
provide the convieneance of auto switching a bunch of circuits feeding a
class of appliances together rather than needing to have individual
timers for the each of them.

(it also prevents their use during peek times (assuming there is no
extra wiring to provide for this (i.e. a boost capability) and they are
hard wired)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Fri, 19 Jan 2007 20:59:09 -0000, "xena"
wrote:

I have just moved a small (1.7kW) storage heater to a temporary location
(next to my desk!) where I plan on using it until March-ish. We are on E7,
and downstairs (where the heater now is) has separate fuseboards to
upstairs. I could wire it into the off peak fuseboard (which feeds just the
lounge storage heater),

Perhaps a bit odd, or is it an old "White Neter" installation ?

but it would be easier for me to plug it into the
mains (on a timer) on account of its temporary status.


That will work fine from the tarrif POV.

There was a previous system some indeterminate time ago in the dark
ages when storage radiators had a hard wired circuit of their own run
through a "White meter".

Users could not take advantage of the night rate to run their other
appliances unless they broke into the hard wired circuit. OTOH the
stotage heaters got a short "boost" during the afternoon.

Other items that run off the downstairs mains overnight are the immersion,
the washing machine and the tumble dryer. I tend to have these come on
about 5am so they're all nice and fresh for me in the morning. I imagine
the storage heater would have done most of its warming up by then and would
be cycling on and off according to its thermostat.


Are these hard wired in?

I would expect the immersion is on it's own circuit. The W/M & T/D
together with the addition of 1.7Kw of storage won't overload a ring
main given the diversity factor.

On balance, would it be ok to plug it into the mains, or do I really want to
be hard wiring a new spur into the off-peak board?


It's OK.

DG

"Derek Geldard" wrote in message
...
On Fri, 19 Jan 2007 20:59:09 -0000, "xena"
wrote:

I would expect the immersion is on it's own circuit. The W/M & T/D
together with the addition of 1.7Kw of storage won't overload a ring
main given the diversity factor.

On balance, would it be ok to plug it into the mains, or do I really want
to
be hard wiring a new spur into the off-peak board?


It's OK.

I've just checked the fuseboard again and the immersion is on it's own
circuit, not on the ring main as I posted earlier. I'm happy now that I can
just plug the storage heater into the mains.

Thank you very much to everyone who posted on this thread.
xena

Derek Geldard wrote:

There was a previous system some indeterminate time ago in the dark
ages when storage radiators had a hard wired circuit of their own run
through a "White meter".

That's not quite as I recall things. The original 1960s "off-peak"
system provided a time-switched storage heater supply via a separate
meter, but this was not referred to as a white meter.

"White meter tariff" came along toward the end of the 60s and was the
same principle that we now call Economy 7, i.e. a 2-rate meter and an
optional switched supply for storage heaters.

Users could not take advantage of the night rate to run their other
appliances unless they broke into the hard wired circuit.

Which of course they did. That's probably one reason why white meter /
E7 was devised.

OTOH the stotage heaters got a short "boost" during the afternoon.

You can still get, I think, "Economy 10" tariff from some suppliers,
giving something like 00:00 - 05:00, 13:00 - 16:00, and 20:00 - 22:00 at
a cheaper rate (but not as cheap as the E7 night rate).

--
Andy