Economy 7 - need confusion clearing up please!

[Simon0211]

We have an Economy 7 meter and tariff.

There are 2 separate fuse boards and one meter with the dual rate on.

Am i right in thinking that ANY electricity we use at night will be cheaper as the meter has a 'timer' to switch to the cheaper tariff? If so then why is there the need for a separate economy 7 fuse board?

We have storage heaters that run off that board as well as the 'normal' board - presumably they store from the night board and can be boosted from the day, but if ALL electricity is cheap overnight then why the need for a separate board?

If someone could let me know i'd appreciate it!

Thanks

 

[littlespark]

Your storage heaters and the board they come from are timed or remotely controlled to only come on at night. All electricity is cheaper through the night, but you don’t want your heaters powered up during the day on expensive rate.

Sometimes the e7 board and normal are combined into one board, but they take up a lot of space and still require 2 sets of “tails” - the thick cable that connects the board to the meter.

 

[static zap]

Cheaper to tumble dry at night -
(If tumble-drier can be trusted)-De lint all innards! - Do check supplier has bill configured with 2 rates !

 

[Simon0211]

ok thanks for this info - I'm def on 2 rates, I had heard that only items connected to the E7 board will give the cheaper rate at night - presumably not the case?

 

[Richard Burns]

The separate board easily allows the items powered during E7 times to be on only during those times. The whole board is switched (probably in your case by the meter). If you have just one board then each piece of equipment for E7 would need to have its own timer.
Some arrangements do mean only the E7 items are charged at the E7 rate and the main board at normal rate but your description does not sound like that (it is fairly old school now).
You probably have something like the below diagram

 

[Simon0211]

Thanks again, my setup below...I assume as was only re-wired recently then i'm not on an old school setup?

 

[Deleted member 26818]

When E7 was first introduced, two meters were required.
Normal meter was black, off peak meter was white, and the two meters were set at different rates.
Both meters could technically supply power at any time of the day, but the white meter was connected to a time clock which would only allow the power through at the set times.

Later a single dual tariff meter was designed, which had two connection points as per the drawing posted by Richard Burns. This meter could be remotely controlled by the supplier to turn on or off the off peak supply.

The introduction of such meters allowed for new tariffs such as E10 to be introduced.
The E10 tariff allowed the supplier to offer an extra 3 hours off peak during the evening in addition to the standard E7 times of midnight to 7am.

I can’t recall the times the extra 3 hours would be supplied during the evening, but the intention was for the supplier to choose hour slots where there was cheaper electricity.
So you could have supply from 7 to 8, 9 to 10 and 11 to midnight, 7 to 10, 9 to midnight or whatever combination the supplier deemed would be cheapest that day.

Many suppliers now offer a cheaper tariff for all electricity consumed at night, but still offer to switch the the second supply on and off remotely, so storage heaters are not on continuously.
In other cases, a time clock is required to control when power is delivered to storage heaters.

 

[Richard Burns]

Your set up when simplified and removing the earths is similar to my diagram but laid out like this


a few more joints and connections to confuse matters, but still the same idea.

 

[Simon0211]

Your set up when simplified and removing the earths is similar to my diagram but laid out like this

View attachment 48736
a few more joints and connections to confuse matters, but still the same idea.

thanks for this Richard - does that mean its 'normal E7' - i.e cheap rate during my E7 hours irrespective of which board the sockets/switches etc run off?

 

[Richard Burns]

Yes, during non E7 hours the top left board should be off and all power consumed by the lower right board will be at normal day rate.
When E7 hours start the top left board will be powered up and anything connected to it will start (if switched on). The meter will then be recording the power consumed by both boards on E7 night rate.

 

[Simon0211]

Yes, during non E7 hours the top left board should be off and all power consumed by the lower right board will be at normal day rate.
When E7 hours start the top left board will be powered up and anything connected to it will start (if switched on). The meter will then be recording the power consumed by both boards on E7 night rate.

Thanks Richard, good to know. There’s also an immersion label on the E7 left board and right main board but my immersion only has one input through a timer switch....something for an electrician to look at I guess. I’ve read that most e7 immersion tanks have a lower e7 immersion and upper normal. Ours only has normal and as far as I can tell.
Thanks again for help.

 

[liebfraumilch]

May I ask where the "2 rate digital meter" is usually located?

 

[Avo Mk8]

May I ask where the "2 rate digital meter" is usually located?

Otherwise known as "the electricity meter" - for a private house, in a box outside in or on the wall somewhere, or indoors by the consumer unit. For an apartment/ flat, generally in a cupboard in a corridor on the same floor, sometimes basement or a central location.

 

[liebfraumilch]

Otherwise known as "the electricity meter" - for a private house, in a box outside in or on the wall somewhere, or indoors by the consumer unit. For an apartment/ flat, generally in a cupboard in a corridor on the same floor, sometimes basement or a central location.

Thanks for replying!

In fact its a little observation* that brings me to this thread. Let me start just from the setup we have.

Our flat is on 4th floor. There's a meter room on the G/f hosting all the meters for the flats in the building.

Our meter looks like this, with three different readings alternating:



Inside our flat there're two fuse boards. I assume one is for OFF peak and one is for ON peak, judging from the connected appliances:





* Observation - we have a Gledhill Torrent thermal store, with two immersions, one connected to a OFF peak socket and one to a ON peak socket. Interesting enough, the OFF peak immersion will turn itself ON during daytime. This can't be right?

When we phoned Bristol Energy the provider, we're told our meter isn't a "Smart Meter", and scheduled ours for a upgrade.

Will that make any difference to our bizarre observation?

 

[snowhead]

Where the meters are located, is there any other boxes seemingly connected to the meters if so can you take a photo and post here?
There may be a separate time switch which has lost the correct time and is switching on early or if the meter has a built in time switch that may be wrong.

And re, will a Smart meter make any difference, given the limited knowledge of E7 and Off Peak installations that the average "Smart Meter" installer appears to have, it's quite likely you'll end up with no E7 working or it working all the time or some other variation.

No offence intended to the few knowledgeable "Smart Meter" installers, who usually end up sorting out the mess left by others.

 

[ferg]

Some tariffs have an afternoon boost.

From memory usually some time between 2 and 4.

Do your storage heaters charge at the same time?

 

[Avo Mk8]

Some tariffs have an afternoon boost.

From memory usually some time between 2 and 4.

Do your storage heaters charge at the same time?

I suppose another way of checking this would be to race to the meter cupboard when the offending immersion comes on, and see which rate is clocking up on the meter (assuming the water temperature is cool enough to trigger demand)

 

[ferg]

I suppose another way of checking this would be to race to the meter cupboard when the offending immersion comes on, and see which rate is clocking up on the meter (assuming the water temperature is cool enough to trigger demand)

Around here storage heater isolators almost always have a neon, I'm not sure if that applies in deepest darkest Englandshire too though.

 

[Avo Mk8]

Some tariffs have an afternoon boost.

E10
Googling reveals that Bristol Energy were (one of the few) willing to take on some E10 customers who had an E10 set-up and wanted to switch to them, and they would bill as if E7 (and call it that).
But I gather Bristol Energy is now in liquidation, so no idea where this will lead.

Edit:
The sale to Scotland-based Together Energy, which is 50 per cent owned by Warrington Borough Council, safeguards 110 frontline workers who will transfer over to the new company.
Service for customers will continue as before after Together also bought the Bristol Energy brand and systems, along with 155,000 residential meter points.

 

[ferg]

THTC, E10 E7 I can't keep up or make head nor tail of the different tariffs.
If the off peak is controlled by a teleswitch or similar the off peak times vary.

Long and short of it People not on Economy 10 also get a period mid late afternoon whether this is only THTC or THTC and E7 I can't remember.

 

[Lister1987]

Wonder if my local council will give me a discount if I switch to a company thry have a vested interest in ? being in Warrington & all

 

[liebfraumilch]

Thanks for all the reponses and thoughts given. Much appreciated!

I couldn't get to the building till today when I can have a better look in the meter room. Here's the setup of our flat:



Obviously, we don't have a Smart Meter.

May I ask where the actual ON / OFF peaks switching is being triggered?

Also, what does the one in black in the middle do? I realise two neighbours' setups don't have that(?)

Indeed, I can potentially run to the meter room located on the ground floor from the fourth floor when I hear the offending immersion kicks in during daytime...... :~)

On a crucial note, when the Smart Meter installer comes next week to replace the meter, what should I look out for to be sure the installation is valid and the timer switching logic actually works properly? With all these tariffs mentioned it does sound like a nightmare!

 

[Mikegh]

Looks to be 2 tarriff CT metering , haven't seen that before

 

[snowhead]

The black unit in the middle is the time switch that enables the Off Peak fuse board for the heaters and water.
It's switched at the times shown, E.7, or should be, by a Radio signal put out on BBC transmitters.
They were originally mechanical timeswitches but changed to this unit, then to timeswitches built into the meter.
The radio signal is being turned off sometime next year so that's probably why you're going to a "Smart Meter".

If the off peak water heater is coming on then the off peak heaters , if switched on must be.

Bristol Energy or their subcontract meter fitters / meter leasing company should be removing the black teleswitch and using a 5 wire "Smart Meter" that will also do the switching for Off Peak.

 

[liebfraumilch]

Thanks for the info! Much appreciated.

May I also ask a quick question - in terms of Smart Meter, does it work under both the E7 tariff and the standard rate tariff?

I just want to make sure the meter does not have to be changed when we later on switch back to standard rate. Given so many people practice WFH after the pandemic, I see there is less sense to stay on E7 tariff.

 

[liebfraumilch]

The black unit in the middle is the time switch that enables the Off Peak fuse board for the heaters and water.
It's switched at the times shown, E.7, or should be, by a Radio signal put out on BBC transmitters.
They were originally mechanical timeswitches but changed to this unit, then to timeswitches built into the meter.
The radio signal is being turned off sometime next year so that's probably why you're going to a "Smart Meter".

If the off peak water heater is coming on then the off peak heaters , if switched on must be.

Bristol Energy or their subcontract meter fitters / meter leasing company should be removing the black teleswitch and using a 5 wire "Smart Meter" that will also do the switching for Off Peak.

Hello snowhead,

Just want to report back that after 4 weeks of hassle we've managed to go from a traditional meter to a "smart" meter.

Indeed the black teleswitch has been replaced by a 5-wire meter.

Interestingly enough, this has not fixed our original problem; that OFF peak circuit is still on during daytime under a E7 tariff.

The installer was quick enough to show us that the 5th cable is constantly live (the one on the right.) Hence no time switching happens.

How does this happen? Any idea who we should speak to?

 

[James]

Unfortunately, you will now have to install your own time switches for the devices you only want powered during the off peak times.

 

[njbrookes]

Yes, during non E7 hours the top left board should be off and all power consumed by the lower right board will be at normal day rate.
When E7 hours start the top left board will be powered up and anything connected to it will start (if switched on). The meter will then be recording the power consumed by both boards on E7 night rate.

Good afternoon, I'm must first apologise if this has been covered elsewhere, but i cant seem to find an easy answer.

Easy question is - are there any Smart Meters capable of switching an E7 circuit in and out without a separate timer? I do have a two tariff contract (E7) and I am concerned I am using power for storage heaters and immersions etc on full price tariff.

Background - I had an almost identical set up to the one on the picture above, one meter capable of switching in a separate consumer unit with all of the E7 heaters and immersions for the 7 hour period (12:30 - 07:30). This worked fine for years, infact from the time the house was built in the early 1980s. A while ago (~3+years ago) EDF fitted a smart meter, I took very little notice until one day in the Covid lock down I could hear my immersion heater on in the middle of the afternoon, I checked and it was the E7 circuit that was powered. I monitored this for a few days and could see that the storage heaters main feed was also live at the same time. It did seem to switch on and off but the time seems to vary.


(both in day time)

I contacted EDF but i cant get a simple answer. looking at my wiring I am unsure if my smart meter has the ability to switch in a timed circuit or if i should have been told to get a timed breaker added?

This is my set up is as below with Red/Black feeding the 24/7 consumer unit (13A ring main, Lights, cooker, shower, etc) and the two grey wires supplying E7 only (timed?) circuit (HHR Storage heater main feed and immersions) -


I still have no idea about live connection from bottom of smart meter
Thanks in advance

 

[NoviAdvenae]

The separate board easily allows the items powered during E7 times to be on only during those times. The whole board is switched (probably in your case by the meter). If you have just one board then each piece of equipment for E7 would need to have its own timer.
Some arrangements do mean only the E7 items are charged at the E7 rate and the main board at normal rate but your description does not sound like that (it is fairly old school now).
You probably have something like the below diagram
View attachment 48732

Richard (love your diagrams). My 'electrician' friend (a DIY-er), said he could help me with a problem but I would like your initial thoughts on it after seeing this diagram of yours. (Well it sounds like you know what you're talking about so it makes sense to ask!). I used to be on economy 7 but now I am on a single tariff as it suits me better. But I still have a 2 rate meter and my second fuse box (white box) still only comes on at night. But this is a waste as I want to use the circuits from that 'E7 Consumer unit' all day and night long - as I am on a single all day tariff now. So his thoughts are to put both fuse boxes on the first tail which doesn't have a timer and which would provide electricity to both fuse boxes all day long. I've uploaded an edited version of your first diagram to hopefully explain what I trying to say. Do you see any problems with this? Much obliged.