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Topic Title: Converting Old Council Control to Economy 7
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Created On: 03 January 2018 05:26 PM
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 03 January 2018 05:26 PM
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robertshepherd001

Posts: 8
Joined: 25 July 2008

Hi, a friend of mine has moved to what once was a council house, and has a contactor that was apparently used by the council to control the heating. He wants to change over to an economy 7 type meter. The DNO won't do anything until the contactor is gone, but won't touch it themselves. It's not clear how it's wired. So, does anyone know how this type of arrangement is connected, to save a lot of "belling out" please?
 03 January 2018 07:10 PM
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AJJewsbury

Posts: 16619
Joined: 13 August 2003

I've never heard of a council directly managing off-peak electricity switching in houses before. Is this a normal house with a normal individual DNO supply? (not something in a managed 'block' with the supply coming in as a submain from elsewhere on overall 'estate')

Using privately owned contactors for E7 etc is common enough, but they're normally controlled directly from the supplier's timeswitch (or radio teleswitch or whatever) - usually to avoid the cost of two large c.s.a. submains from a remote metering position.

Any clue in the name of the current tariff on the customer's bills?

Or pictures of the intake/metering position might be illuminating, if you can post one (you'll need to find somewhere publicly accessible on the internet to host it and just post a link to it here).

- Andy.
 03 January 2018 07:37 PM
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mapj1

Posts: 10414
Joined: 22 July 2004

There were all sorts of weird and wonderful multi-tariff arrangements in the days of the electricity board - including heating wired to un-metered circuits, various arrangements of two meters and a time switch, one meter and a timer, meters with built in timers, and indeed radio controlled external contactors, including some really odd ball designs with a switched contact to neutral so the solenoid coil is live all the time, even if not pulled in, so take care.
I suspect now it will belong to a 'building network operator' which may not be a role well defined. If you can date it, or as suggested above put a pic on the web, someone may have an 'aha' moment.

-------------------------
regards Mike
 04 January 2018 12:33 AM
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rocknroll

Posts: 9595
Joined: 03 October 2005

In the late seventies and eighties there were administered by the DTI a number of initiatives where LA's purchased energy in bulk, in some of the larger authorities the clock, timeswitch etc. was fitted by council electricians and in some of the smaller ones the job was contracted out to the then electricity board in the area.

Generally this arrangement was for very low income families and OAP housing where they paid a few quid on top of the rent for energy, there was a great deal of subsidy from the then government, this was to ensure that these vulnerable people did not go without heating, light and cooking facilities, also the appropriate council arranged their own metering and non-metering arrangements as was required. This was slowly phased out as we moved towards privatisation.

Just a note this arrangement is still ongoing and gaining in popularity I believe now they call it 'Community Energy' there is a white paper kicking around about it.

Regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
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"Oh! The drama of it all."
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"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------

Edited: 04 January 2018 at 08:27 AM by rocknroll
 04 January 2018 12:13 PM
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robertshepherd001

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Thanks Guys, It is a legacy council system. A contactor turns on the storage heating at night. The contactor is controlled by a set up similar to street lighting. A clock somewhere energises the contactor supply. To date, enquiries with the local authority and DNO have not been fruitful. The DNO have put a meter on the load side of the contactor as it's now a private residence (so electricity for heating isn't included in the rent, as was clarified above). The DNO were happy to put a meter in, but not advise how to convert to economy 7, or explain how the system is wired. The property has 2 meters, each independently fed from the DNO supply, and 2 consumer units: one for night storage heating via the contactor, and one for the remaining domestic electrical supplies. It's not easy to trace the cabling, as it is embedded I the building fabric, without any idents. Also, all the terminations are capped and sealed, so trying to test which is which is not possible. However, by the number of connections and tails, it looks like the ouputs of both meters are paralleled before terminating at the consumer units, which doesn't seem correct or necessary. Any further input will be appreciated. Thanks.
 04 January 2018 01:24 PM
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mapj1

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Hmm. 2 meters says 2 tarrifs. supply tails parellled at the building CU suggests that all of the the supply in the building switches to the second meter at some point, (day and night rate meters with switches in perhaps ? Or it may be a cock-up) and almost incidentally, the heating is put on via the contactor when the time signal says so. (Or cuts off early based on a thermsotat may not be just time, there are /were also clever systems that cut the storage off earlier when the outisde temperature is higher than some limit.)
By the sound of it , short of being there while the company fuse is out, simply removing the contactor is not safe and the metering will all have to be re-jigged at the same time.
If the DNO (or the metering company if different) have put a meter on the load side of the contactor, and not as would be more common, 'upstream' of it, then they have in effect adopted it.

However it is most unusual to configure a meter in a position where it loses the supply while the heating is off - are you quite sure about that? I ask because if, as is more common, the contactor was actually on the output side of the meter, then they would be assuming it was customer equipment, like the CUs. (And in the same way, any henly blocks or similar in the tails on the customer side of metering need not be DNO sealed, as they are after the metering)

Is the contactor only supply the heating CU, and is it the heating CU's only supply ?
Sorry it is more questions than answers, but from here it is not really making total sense yet.

-------------------------
regards Mike
 04 January 2018 01:25 PM
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sparkingchip

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If the tails are interconnected after the meters it is very dangerous, because the off peak will be back fed back out of the dwelling into the unknown system.

Also the heaters will always be on. I have to call at a house with a messed up system like this on the way home, one meter, two main switches, interconnection at a Henley block, then onto two consumer unit with one supplying an electric storage AGA cooker.

Someone obviously thought they could save money on the electric bill, but left it dangerous and uncontrolled.

Andy B.
 04 January 2018 04:27 PM
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robertshepherd001

Posts: 8
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Mike, you are correct, it is actually 'upstream' of the contactor. Thanks. Is it possible to upload photos to this forum please?
 04 January 2018 05:38 PM
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mapj1

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Not directly - you need to put the pics somewhere else on the web perhaps dropbox /imagur/ photobox/ or your own website so they can be seen from anywhere, and then put a link to them here.
More complex, it can be persuaded to look embedded, if that external link is between triangular bra ( < ) and ket ( > ) operators enclosing the magic code img and /img but note it needs to be an http link, not https, and the right size and shape - the forum software is a bit poor on this sort of thing, and it often goes impressively wrong.

-------------------------
regards Mike
 04 January 2018 05:56 PM
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ArthurHall

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Years ago when I was an inspector for a board I did a lot of work on this type of installation. In our area it was quite common to have a central timeswitch owned by the board controlling a 2.5mm submain and contactors that were owned by the householder. The off peak meter could be fitted either side of the contactor.
 04 January 2018 11:21 PM
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sparkingchip

Posts: 10542
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I had a quick look at the Aga I mentioned above earlier this evening.

The Aga has a built in contactor and one method of installation in the manufacturers instructions is to make the supply connection as a 30 amp circuit on the 24 hour supply then use a 3 amp circuit from the off peak to switch the contactor, so the off peak is only used for signalling.

I have always used a immersion heater type timer with a boost button to allow a daytime boost if the appliance temperature is low in use.

But that only works with a single dual tariff meter, not with two separate meters.

Electric storage Aga installation instructions.

What kind of storage heating was installed in the house, separate heaters in each room or one large space heater supplying ducted hot air?

Andy B.
 05 January 2018 11:14 AM
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robertshepherd001

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Hi Arthur,

It is exactly that arrangement, except it's a normal tariff meter fitted by the DNO when the house was originally sold.

The 2.5mm submain, which I believe runs around the estate, is in SWA, and loops in and out of a 13A fused spur, which supplies the contactor coil when energised from the clock, for which the location is unknown! The DNO won't touch it now, until it's all rewired, and the contactor is taken out of the installation. Cheers,
 05 January 2018 11:15 AM
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robertshepherd001

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Storage heaters are in the rooms. Thanks.
 05 January 2018 12:29 PM
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AJJewsbury

Posts: 16619
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It is exactly that arrangement, except it's a normal tariff meter fitted by the DNO when the house was originally sold.

What sort of meter is it? no chance it's a dual rate meter with a 5th wire is it?
- Andy.
 05 January 2018 06:46 PM
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kellyselectric

Posts: 265
Joined: 22 July 2016

Ive never heard of such a weird system you couldn't make it up! But serious head on now surely if the contactor is fed from this 2.5 mil supply that goes round the estate then couldn't you just take out the contactors coil supply fuse from the fused spur you mentioned then get the DNO to pull their main fuse you then remove it and at the same time get the DNO to put in a proper offpeak arrangement they should agree after all your doing the donkey work and they are going to earn out of it in the end. Whats not to like?
 05 January 2018 11:35 PM
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mapj1

Posts: 10414
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I'd like a pic, but I think Kelly is right - remove spur fuse, so coil cannot be live, remove wiring from contactor output, and place in dummy Henley blocks for later connection.. So long as you are not the flat with the time switch that the others still need.
With main fuse out, remove wiring to contactor input. Maybe a job better in summer when the heating is not needed ?

-------------------------
regards Mike
 06 January 2018 12:38 PM
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AJJewsbury

Posts: 16619
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The DNO won't touch it now

Not wanting to teach anyone to suck eggs as it were, but I'll mention this just in case... Assuming you're on the mainland UK then metering isn't the responsibility of the DNOs any more - meters belong to the electricity supplier (i.e. whichever little outfit the customer has 'switched' to and pays the bills to) who sometimes sub-contract metering to some other 3rd party meter operator. Thus DNOs try to have as little as they can to do with meters these days - if their work directly affects the meter (like having to move the cut-out say) then they'll generally move the meter for you at the same time, but otherwise they claim their responsibility stops at the outgoing terminals of the cut-out and certainly won't want to be involved with changing meters. So if by "DNO" you meant the customer's electricity supplier, then fine (and I apologise for wasting your time), but if you really did mean the local DNO, you might have much more luck by contacting the customer's supplier instead (or better still getting the customer to do it, at least to 'introduce you').
- Andy.
 21 February 2018 02:28 PM
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robertshepherd001

Posts: 8
Joined: 25 July 2008

Thanks for replying Guys. Also, thanks Andy, I do mean the supplier, however, the DNO and supplier are both SSE, so I forget to distinguish!

Taking the fuse out of the spur means that the heating won't come on. I've considered taking out the contactor, though this would mean having to use the double pole isolator to manually switch the heating, or replace the contactor with a rated manual switch. Or, even installing a local timer to control the contactor. However, there is little to be gained as none of this gets the tariff changed.

I've written to the supplier, as their online and phone help service just can't understand or deal with this. We'll see what transpires!
 21 February 2018 02:28 PM
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robertshepherd001

Posts: 8
Joined: 25 July 2008

Thanks for replying Guys. Also, thanks Andy, I do mean the supplier, however, the DNO and supplier are both SSE, so I forget to distinguish!

Taking the fuse out of the spur means that the heating won't come on. I've considered taking out the contactor, though this would mean having to use the double pole isolator to manually switch the heating, or replace the contactor with a rated manual switch. Or, even installing a local timer to control the contactor. However, there is little to be gained as none of this gets the tariff changed.

I've written to the supplier, as their online and phone help service just can't understand or deal with this. We'll see what transpires!
 24 February 2018 08:51 PM
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sparkingchip

Posts: 10542
Joined: 18 January 2003

I prepared an EICR yesterday and added a note, a Horstmann E7 time time clock has been installed on the E7 supply to control the bottom immersion of a E7 cylinder with the boost top immersion heater wired to the 24/7 supply via a SFCU.

The note suggests retiring it all, although it is safe to use.

There isn't a coding for "Wired by a idiot ".
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