Economy 7 :: What's what?

[DaveyD]

Hi everyone

My friend has this E7 set up and TBH I don't know how it works switching wise.

It has two 17th ed. CU's recently installed. One for daytime and one for night time. I thought E7 has one CU and just switches over everything, so what's going on here please with the two CU's.

Here is the meter box



The E7 CU has the night storage heaters and water heater on. My mate has bought a new 2.77kw water heater and to "save money" bought a single rather than a Twin immersion Heater



So he has the plumber wire it to the day rate switch (top switch). Now he wants me to wire to E7 switch (bottom).


Sorry in advance if this question is too simplistic for you and thank you.

Kindest Regards, David

 

[adslev]

I know that any installs i have worked on with E7 have had one board for general power, lights, sockets and the other board only for the storage heaters, like you said they work of a lower tariff, tbh the storage heaters should have stored sufficient heat if they are operating correctly at night and I would leave them on their own dedicated CU, IMO of course!!

 

[robsparky1975]

Not sure on what it is you need to know,1 consumer unit is unrestricted(peak supply).other unit is economy 7(restricted between 23.30-0630),the electric meter had certain readings a b etc, rate 1(say 10p kwh),rate 2 say 5p kwh,in your picture the black unit is a switch which powers up the restricted supply for the rate 2,any other power taken at nightime from the unrestricted supply will be priced at the rate 2 as this is done automatically in the meter.whats wrong with the immersions?

 

[DaveyD]

Thanks for your reply guys.

Not sure on what it is you need to know,1 consumer unit is unrestricted(peak supply).other unit is economy 7(restricted between 23.30-0630),the electric meter had certain readings a b etc, rate 1(say 10p kwh),rate 2 say 5p kwh,in your picture the black unit is a switch which powers up the restricted supply for the rate 2,

Switch, ok thanks.

any other power taken at nightime from the unrestricted supply will be priced at the rate 2 as this is done automatically in the meter.whats wrong with the immersions?

If I rewire to the e7 then he wont have any hot water in the daytime. Is the main C/U NOT E7 at night too?

 

[robsparky1975]

how many immersions now just 1

 

[DaveyD]

how many immersions now just 1

Yes just one Rob

 

[terminator]

Just leave it on the day rate switch and add a timer - that way he can swich it manually as well. If you put it on night rate, he has no use or option during the day.

 

[robsparky1975]

if only 1 immersion he needs an economy 7 water heater controller,something like a horstmann,both the peak and off peak supplies from ccus are wired into these,with 1 heat resistant flex(2.5mm)going to a single immersion heater,this gives the off peak as normal at night time and has a dial on the front of unit which can allow a 2 hour daytime boost via the peak supply.dont take this the wrong way(im not sure what your level of experience is),this needs to be done by a competant electrician,if your competant then carry on and disregard me asking,its just to be on the safe side im sure you understand.

 

[DaveyD]

So are you saying that as I suspected the main C/U will run the whole house at E7 overnight. The black switch in the meter box is just to turn the storage heaters on and off (plus the now redundant water heater feed)?

 

[DaveyD]

if only 1 immersion he needs an economy 7 water heater controller,something like a horstmann,both the peak and off peak supplies from ccus are wired into these,with 1 heat resistant flex(2.5mm)going to a single immersion heater,this gives the off peak as normal at night time and has a dial on the front of unit which can allow a 2 hour daytime boost via the peak supply.dont take this the wrong way(im not sure what your level of experience is),this needs to be done by a competant electrician,if your competant then carry on and disregard me asking,its just to be on the safe side im sure you understand.

Thank you , no offense - I understand where you are coming from. Yes I am competent and qualified I have just never done E7 before. So not as experienced as many here with that.
Kind Regards, David.

 

[pushrod]

Slightly off topic, but you need to be really careful with a lot of E7 deals as they are a con and only actually give you a saving if you are using absolutely masses at the cheap rate as they often charge more for the ordinary rate than you can get with other deals. Unfortunately i know from experience. When i went through the charges carefully i discovered that using the dishwasher and washing machine on timers to come on with the E7 was actually costing me money

 

[DaveyD]

i discovered that using the dishwasher and washing machine on timers to come on with the E7 was actually costing me money

! I don't have it here - but how was that? Regards, David

 

[robsparky1975]

So are you saying that as I suspected the main C/U will run the whole house at E7 overnight. The black switch in the meter box is just to turn the storage heaters on and off (plus the now redundant water heater feed)?

yes the switch clicks on at 23.30,the unresticted supply gets reduced rate prices overnight,this is why a few people do there laundry after midnight.remember that you will need the off peak water heater feed to go through your water heater timer.you need peak and off peak.look up the horstmann range they have diagrams and everything,also,have a google for economy 7 and a good read up with pics should help out a bit more.

regards rob

 

[robsparky1975]

Slightly off topic, but you need to be really careful with a lot of E7 deals as they are a con and only actually give you a saving if you are using absolutely masses at the cheap rate as they often charge more for the ordinary rate than you can get with other deals. Unfortunately i know from experience. When i went through the charges carefully i discovered that using the dishwasher and washing machine on timers to come on with the E7 was actually costing me money

good point,although it says ECONOMY,check carefully on what the kwh prices per unit are,these suppiers can be sneaky.

 

[pushrod]

! I don't have it here - but how was that? Regards, David

because although the E7 rate was cheap the standard rate was actually more expensive than other rates that were available. We moved into our house and just assumed for a couple of years that it was sensible to have and was saving us money ... WRONG!
Got rid of it when we finally checked it out.

 

[robsparky1975]

yeah you may have been paing 5p kwh for e7 but 15p kwh standard,theiving gits are they not,it soon adds up

 

[DaveyD]

because although the E7 rate was cheap the standard rate was actually more expensive than other rates that were available.

Wow! Who would have thought that. Thanks for sharing.

 

[robsparky1975]

compare prices at somewhere like uswitch

 

[DaveyD]

Back to OP ... so he could leave on as wired in on the daytime switch and just switch on at night and off in the day. He would be the sort to remember this. Then he can manually boost if he needs to by flicking on for an hour or two at peek rate in the day?

 

[DaveyD]

compare prices at somewhere like uswitch

We are personally with Eon and have a great fixed deal till 2011. Had for a year and £30 per month cheaper than npooer

 

[baldelectrician]

You could change the eliment for

27" Dual Element Dual Stat Immersion Heater - QVS Electrical Supplies | Electrical Wholesaler

This is a DUAL eliment - it goes into one immerser point at the top of the cylinder. It takes two supplies and is designed for the problem you have

 

[robsparky1975]

problem solved,its either the dual immersion or a timer,the choice is yours.

 

[DaveyD]

Many thanks to you both ... Or he could just leave as wired and switch on at night and off in the day. He bought the single as a replacement to save money as the twin was dearer. I was worried that by moving switches he would be scuppered if he needed hot water in the day. If I can confirm the whole house would be E7 at night then its no problem TIA

 

[baldelectrician]

The problem leaving it this way is he needs to heat the whole tank at full price

The dual eliment means the top part or the bottom part is heating, not both

 

[RomRobi]

Wiring the e7 to a restricted supply is baseless unless you intend to further restrict supply time within economy 7 supply time. There have been problems with people adjusting the e7 for day use when on economy7 supply, and it will not work. If on unrestricted supply you can always adjust the e7 to your own taste. But remember one thing the boost control and e7 cannot and will not run simultaneously, as result of the relay operation. Just think this whole episode as two shower operated by a relay from one shower circuit. Boost only during the day, and time e7 for night supply and you cant go wrong

 

[La Poste]

Could someone explain this picture a bit to me please:



It seems the E7 teleswitch has two line cables sleeved in brown tape.
These are presumably line in and line out of the teleswitch.

The thin black cable running from the teleswitch is a control cable that works with the meter.
Maybe telling the meter to record the electricity used as the cheaper rate electricity once the teleswitch
has switched on to E7.

But there is only one neutral to the teleswitch and I don't know why.
Could someone tell me why there is only one neutral to the teleswitch and yet two lives?

I see two neutrals connected to the left hand Henly block.
Is one of those neutrals from the main board and one from the E7 board?
Maybe that's it, maybe they have connected both neutrals at the Henly block
instead of connecting both at the teleswitch to save a bit of cable.

And any ideas what the clamp is around the neutral tail?
The small white thing attached to the neutral right near the meter.
The two earth cables presumably are one for the main board and one for the E7 board.

Thanks.

 

[snowhead]

It seems the E7 teleswitch has two line cables sleeved in brown tape.
These are presumably line in and line out of the teleswitch.... YES

The thin black cable running from the teleswitch is a control cable that works with the meter.
Maybe telling the meter to record the electricity used as the cheaper rate electricity once the teleswitch has switched on to E7....YES

But there is only one neutral to the teleswitch and I don't know why.
Could someone tell me why there is only one neutral to the teleswitch and yet two lives? Neutral is only to power the switch

I see two neutrals connected to the left hand Henly block.
Is one of those neutrals from the main board and one from the E7 board?..Must be,,YES
Maybe that's it, maybe they have connected both neutrals at the Henly block
instead of connecting both at the teleswitch to save a bit of cable.

And any ideas what the clamp is around the neutral tail? ..Current Transformer for remote energy monitor
The small white thing attached to the neutral right near the meter.
The two earth cables presumably are one for the main board and one for the E7 board.

Thanks.

See above