switching between off-peak & normal supply

[sinbadbris]

I have an off-peak power supply that gives 3 hours in afternoon (12.30 to 15.30) and 7 hours at night.

When I rewired my house I fitted extra sockets for off-peak supply next to washing machine and dishwasher which works fine when I remember to change the plug over.

What I would like to know is if I can get an automatic switch that will select the off-peak when available and normal supply when not.

 

[ColJack]

errr, that's not how it works..
when you are on "off peak" time, then ALL the electric in your house is being charged at off peak.. there's no need to fit special sockets to use it..

the "off peak" board is usually to "charge" the heaters which is the reason that it is switched on when it's off peak hours...

 

[Lectrician]

errr, that's not how it works..
when you are on "off peak" time, then ALL the electric in your house is being charged at off peak.. there's no need to fit special sockets to use it..

the "off peak" board is usually to "charge" the heaters which is the reason that it is switched on when it's off peak hours...

Assuming it is an economy 7 or 10 type tarriff (which it DOES look like). Not all off-peak arrangements provide cheap lecky to the whole installation during the off peak hours. I was working on an old 'white meter' install only last week - along with several water filled storage rads - what odd contraptions they are.

A photo of the metering arrangements / fuseboards would help us confirm.

 

[Paul_C]

Since the 24-hour supply remained on the regular rate throughout, the old "white meter" tariffs were generally quite specific about what items could be connected to the low-rate supply, so adding sockets would quite likely be a violation of the terms (chances of an odd socket on it being detected, unless obvious from having wiring clearly visible from the off-peak CU would be pretty remote, of course).

Edit for typo.

 

[Chri5]

All old eco 7 required seperate wiring due to seperate meter and timer for on / off- didn't they ?

New setup, is via a one meter system that has dual readings- so use off peak is recorded as such, on peak ditto- thus the whole house use varies from tariff to tariff depending on contract type / peak and off peak times ?


Or have I got it muddled up

 

[Paul_C]

That's pretty much it. All the newer E7 (and similar tariffs) switch the entire installation to the cheaper rate at the appropriate times. The contactor is just to enable a switched feed for storage heating etc. to be provided.

But many of the older tariffs kept the main CU running on the normal tariff at all times (via the regular "black" meter), and provided a separate white meter to provide power to the cheap-rate CU for heating.

 

[sinbadbris]

Thanks to the majority off people for their replys.

My supply is the old type off-peak which, 'ColJack', doesn't switch all appliances over to the cheaper tariff as you suggested.

There are two meters in the meter box along with a timer which switches the off-peak on.

I have three consumer units in the garage. One for the lighting, one for the ring main and other socketed appliances and a final one for the off-peak (storage heaters, hot water and dishwasher).

 

[Paul_C]

So with the older-style "white meter" system, you could do it with a suitably rated DPDT relay in a small enclosure.

Wire the 24-hour supply to the N.C. contacts, the off-peak feed to the N.O. contacts, and the commons to the socket. Connect the coil across the incoming off-peak supply. Then when the off-peak supply is available the relay will operate connecting the socket to that feed. When the off-peak supply switches off, the relay will release and reconnect the socket to the 24-hour supply.

 

[electronicsuk]

Would it not be easier to switch to a more up-to-date off-peak tariff that provides you with a single meter?