Economy 7

[uksparks]

Hi,

I need to put 4 storage heaters in for a customer...

Its having a new board, thats separate to the storage heater board (only 4 heaters, so a small cu)

See photo below of setup at present.

Ill be honest, I have only ever change boards and setups that exist.

They said EDF will not fit the meter until the storage heaters and board are in place, but don't really know what I need as I don't know what im going to be dealing with on the supply side...

Presumably they will change the meter to something different, but how many outputs will it have? Any ideas?

I was just going to put the heaters into a board on its own and take a feed to it, but will i need a contactor to pull it on? I don't know as it doesn't exist, thats the issue.

Presumably I will have L and N in to the meter, and L and N out, but do I have two lives or a L and a fly lead to a contactor? It needs to be on a timer you see, which they said the meter will do that, but I have not got a great deal of experience with meters in this respect to be honest. Like I say, I'm ok when it exists, but when its imaginary...

Any help much appreciated.

 

[markhtly]

As far as I know you'll just have an extra line conductor from the new fangled Smart Meter that's used for the new tariff . All the gubbins contained for switching the tariff / timers etc is contained within the new meter .

So in other words , you'll have an extra line tail plus a neutral tail from the new smart meter to the heating dis board .

 

[telectrix]

just take the meter tails out of the existing DB, feed into 2 henley blocks, then from the henleys fit new tails to the old DB and to your new DB. then the supplier/DNO will fit a dual tariff meter which has 2 sets of readings. day rat and night rate. ( don't forget earthing 16mm to new DB ).

 

[uksparks]

As far as I know you'll just have an extra line conductor from the new fangled Smart Meter that's used for the new tariff . All the gubbins contained for switching the tariff / timers etc is contained within the new meter .

So in other words , you'll have an extra line tail plus a neutral tail from the new smart meter to the heating dis board .

That's what I am thinking is going to happen, but I have economy 7 and just one set of tails...

I really need to speak to EDF to find out whats going to happen.

 

[telectrix]

not a problem just split the tails.

 

[driverman]

That's what I am thinking is going to happen, but I have economy 7 and just one set of tails...

I really need to speak to EDF to find out whats going to happen.

just a note though: Have you informed EDF that you are increasing the load ie 4 x strorage heaters?
Have they approved the increase load. It doesn't follow the fact that you have applied for E7 metering that they know you intend increasing the load. just a thought.

 

[7029 dave]

Looks like 100/80amp cut out, IMO fit seperate DB for your storage heater's, other board for your genral domestic. They will fit integral meter with 5th terminal, or teli switch.

 

[uksparks]

Yes they do know , they upped the fuse to 100A too.

if it's got a separate teleswitch then I'll need a contractor.

on the basis it's just got a 2nd line out, presumably I split the neutral into a Henley block then take it to both boards?

 

[Richard Burns]

The likely approach at the moment (though you should have been around your area and know the type of new meters installed) appears to be the dual rate meter that simply switches metering from one rate to the next and does not switch the power in any way.

The alternative is for them to supply a separate line for the Economy seven that is only live during off peak hours.

The second one is easier for you to manage as no time control is required on your side.
Just install board and equipment and wait for it to be fed from the meter.

The first one would require time control to the off peak hours. However, depending on the supplier and the area, the off peak hours may not be consistent and this limits your flexibility.

If you need to have the installation in place then if you have storage heaters with integral timers, you can just supply the board from a henley split and if turns out they have a separate line for E7 then just replace your line tail from the Henley block with a line tail to the off peak supply (perhaps through an isolator for convenience).

If you need to time control non integrally timed Storage heaters then a timed contactor switching arrangement would be needed, the timer can be fairly simple but the contactor would be more of a problem if you were switching the full load as I am not sure you can get modular contactors at that rating.

However you could use three or four small modular contactors one for each SH or two then if one fails at least the others work, however this would require a much larger board. The alternative would be to have a contactor timer arrangement in an enclosure that could be slotted into place if required.

 

[uksparks]

Thank you Richard for the lengthy reply, much appreciated.

Ill try and get a straight answer from EDF tomorrow and see what they say, to be honest I've seen such a variety or setups, nothing appears to be very standard in this area.

I don't know why they can't just terminate it into a block or isolator because I would be able to go along and know what's what, it's blooming rediculous really as its not making life easy.

I could get a board and put it ll in then it not be big enough if I need a Contactor etc, because if it is only 4 heaters I can get away with a small board that just house it all and the RCD.

 

[Richard Burns]

If you just fit a board with a couple of extra ways, say, then you could install timer and have a standalone contactor adjacent just switching the supply if required.

 

[dingledong]

Get a double board one with 24/7 elects on one side and with economy 7 on the other side

 

[ferg]

I always install 2 separate boards.

You wouldn't need a contactor for a teleswitch.

TBF the teleswitches are being phased out for dual tariff meters.

Henley for the N and 24hr line to 1 board off peak line to the other.


The thing to remember about E7 & E10 is that they do not have fixed hours, just a guarantee of so many hours.

Teleswitches round my way are usually on and off early evening and the remainder 12-7 for E7 and E10 is so rare I couldn't tell you

 

[Andrewr3]

I always install 2 separate boards.

Agreed, I find that the available dual tariff boards are rather restrictive with configurations and not so easy to obtain quickly. They are also rather large and in one unit so less options when trying fit in. I recall the older square D dual tariffs are a hassle to work on because of safe isolation complications. For new builds dual tariff board probably have their uses.

 

[7029 dave]

No contactor required with teli switch or integral meter's unless you provide contactor with clean contacts(2small wires normally switched off N) from your off peak set up.

 

[dazza1981]

I have eco 7 in my house and i have 1 fuseboard !!!
One set of tails for the on peak feeding the main switch then an rcd for for the circuits.
Then Another set of tails for the off peak which feeds another 80 amp rcd for my storage heaters and hot water which obviously only become live when the meter switches it on at around midnight !!
sssssssimples !!!!!!!

 

[dingledong]

The reason it's hard to get the unusual configurations is because no one uses them so they have to be ordered

 

[Octopus]

Thank you Richard for the lengthy reply, much appreciated.

Ill try and get a straight answer from EDF tomorrow and see what they say, to be honest I've seen such a variety or setups, nothing appears to be very standard in this area.

I don't know why they can't just terminate it into a block or isolator because I would be able to go along and know what's what, it's blooming rediculous really as its not making life easy.

I could get a board and put it ll in then it not be big enough if I need a Contactor etc, because if it is only 4 heaters I can get away with a small board that just house it all and the RCD.

Because one of their key reasons to exist is to annoy anyone touching electrics!

You could install a CU like this:

http://www.gil-lec.co.uk/wylex-nhii...NjTlfBocpgnJ9axHyVlNtuWngHv2HtVztWxoCsYrw_wcB

 

[uksparks]

I'll be honest Murdoch, I'm not a fan of boards with two supplies in them, I feel it's not the best thing you could do, I know you shouldn't touch it unless you know what your doing but I feel it would be possible for someone to switch one switch off and not realise there's two feeds and leave half the board live, I know you would have to be rather special but...

 

[davesparks]

There's only so far you can go to protect idiots. If they cant read the sticker that tells them there's more than one main switch/point of isolation then there's no helping them really.

By the same token they may well just assume that the second board is only going to be live at night so don't need to switch it off, until the afternoon boost kills as they have a go at changing the stat in their immersion heater.

 

[ferg]

I normally use 2 boards because each heater on it's own breaker plus HW.

3 beds, kitchen, hallway, bathrooms, sitting room etc.

Then with the normal ccts plus convectors on some of the storage heaters on the 24hr board.

It all starts getting a bit much for 1 board.

 

[PEG]

The tele switching arrangement is quite common round here on 60's ish properties,where they started life with one rewireable board for non heating,and another small one for either underfloor/storage and/or emersion. Can get a bit confusing where previous changes have swopped hot water heating to other side,or indeed on one occasion,someone added a switched 24/7 option on the E7 emersion circuit. Original mechanical timer for underfloor heating in parents house,still working fine from 1964,comes on 3hrs in the afternoon and about 7hrs through the night. Neighbour across the way told me last week,the nice man from Norweb,left the seal off the time clock door for when "you need to warm up a bit out of hours..." i said that was not really allowed,she said he would'nt get into trouble as he's probably retired,i asked why she thought that,she says "It was 1976..." :stooge_curly:

 

[driverman]

in the past contactors were only used if the off peak load was large. In other words too great for the t/switch.I wouldn't of thought 4 x storage points would be classed as large.