Storage heaters...dual supply and a new way to do it?

[kris jones]

Hello all,

I will try and make this a painless as possible but grateful for anyones thoughts.

I am currently contracted to install heaters for an eco company. These dimplex units require a permanent 24hr feed to operate the cpu and fan and a 20a dual feed for the heat fed from a second CU and fifth tail from the meter as per normal. Being relatively new to the game I wasnt actually aware of the need for 2 feeds until these were supplied and I believe the old school versions just had the one supply from an eco 7 dual board?

Im told that this method is now outdated and you can simply run a feed from the main CU to a spur and use this to supply the 24hr feed in a 1.5mm flex (very little power requirement) and then spur off this spur to a timed spur (immersion type if over 13a with a 2.5mm flex to the elements) which would be set to only come on at say midnight to 7am as would normally be on a dual supply.

The issue is then the cheap rate kicking in and here is my question....... Im led to believe that you can contact you energy supplier and 'simply' ask them to make your night rate cheaper on the standard supply which would make the above wiring situation work a treat BUT Ive tried this and once talking to a phone operative they just havent got a clue what your talking about and default to 'so you want the meter changed to a 5 tail meter' and thats about the limit of it!!!

does anyone have any experience of this or suggestions? Surely this is what smart meters are for??

Thank you

 

[davesparks]

Using a timeswitch relies on the timeswitch being set to the same switching times as the E7 period (bearing in mind this can be different for each installation) and also relies on someone checking it every time the power goes off or the clocks change etc.
Doing it this way is just a bodge around to avoid doing the job properly.

If the property has an E7 supply then it will work as the whole supply is charged at the night rate rate during the off peak hours, additionally the off peak output of the meter is energised at off peak times.

If you are asking the supplier to 'make the night rate cheaper on the standard supply' then of course you will have trouble as you are talking nonsense and not being clear about what you need from them or using appropriate terminology.

 

[snowhead]

There are basically 2 forms of Off Peak, but there have been many variations of how the different DNO's achieved it.
Using the term 5 wire is not acurate enough to describe what's required.

The original system where a separate C.U becomes live only during the Off Peak rate hours.
This uses either 2 meters and a timeswitch (originally supplied by the DNO) or a Dual rate meter with either a separate Radio Teleswitch or built in Teleswitch to enable the Off peak supply. Only the Off peak supply is charged at the lower rate

Or the later system where a single output Dual rate meter with built in Radio Teleswitch is used and all electricity used during the Off peak period is charged at that rate.

New type Storage heaters have their own timed controls so only need a Dual rate meter with single output.

If changing from an earlier Off peak system to a later one both C.Us would need to be commoned onto the single meter output and you would need to check if there is an Off peak immersion heater and if so fit a separate time switch for that.

This is the meter fitted in my house, note it's 4 wire but Dual rate E.7.
Just to confuse, I now don't use E.7 so both readings are charged at the same daytime rate.