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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> Dual Tarriff digital electricity meter https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1247257356 Message started by stocksie on Jul 10^th, 2009, 9:22pm

Title: Dual Tarriff digital electricity meter
Post by stocksie on Jul 10^th, 2009, 9:22pm

Can someone enlighten me as to weather this has 2 outputs live & neutral peak and live and neutral off-peak?
Ive only ever came across an older analogue dial one which was fed of the existing meter.

Thanks lads. ;D

Title: Re: Dual Tarriff digital electricity meter
Post by Lectrician on Jul 10^th, 2009, 9:29pm

There are many types these days.

Modern ones are all-in-one dual rate (or multi rate set to two rates), and have the teleswitch built in, or a programmed clock which is kept upto date via the AM sync. This has live and neutral in, neutral out and two lives out.

Common dual rate meters have a switched neutral signal to switch them to low rate. This is done by a teleswitch or timeclock. The tleswitch or time clock usually also switches an 80amp off peak load too.

Title: Re: Dual Tarriff digital electricity meter
Post by stocksie on Jul 11^th, 2009, 11:25am

Thanks for that Lec.
The job I've been asked to do is a block of 8 appartments all with night store heaters.
i was thinking a 4c 25 mm SWA from the intake/meter position to each appartment and using metal clad Switchgear and D.B's.
Can you advise if this would be the correct scenario as I cant think of another way to do it.
I wass going to mount the D.Bs in the corner of a cupboard in each appartment and come side entry into one of them and run the 2nd set of cores through to the other D.B.
Seems like more sense than having 16 SWA's in total ! :o

Title: Re: Dual Tarriff digital electricity meter
Post by stocksie on Jul 11^th, 2009, 11:28am

Was going to use Hager aswell as they seem to do a good range of M/C for the supply/ meter end and nice looking D.B's for the appartment end.Very cheap aswell against Wylex,crabtree etc
It's a budget job aswell....so the bloody project manager keeps telling me

Title: Re: Dual Tarriff digital electricity meter
Post by Lectrician on Jul 11^th, 2009, 11:40am

Depending on the runs and where the cable will be installed in terms of depth/zoning, I would run two 16mm split concentric cables per flat. Standard CU's in the flats, and two 60 or 80 amp switch fuses at the origin.

Title: Re: Dual Tarriff digital electricity meter
Post by stocksie on Jul 11^th, 2009, 1:17pm

Why the concentrics ?Flexability of the cable?I d still have to run an earth in with them aswell though.
Not really sure as the runs as yet but SWA's wont need RCD protection whereas Concentrics will.
It's an awkward scenario whatever s used.
Would you 16 mm c ores would be enough as Xple carries over 80 Amps i know,84/6 as I recall.

Thanks

Title: Re: Dual Tarriff digital electricity meter
Post by Lectrician on Jul 11^th, 2009, 1:29pm

Concentrics have a suitably sized earth conductor. No need to supplement it.

Concentric is cheap and easy to install and temrinate. No glands required. Direct into a standard moulded CU and switch fuse.

No need for RCD protection if you plan the run well. Usually in service voids and boxed in areas etc.

Title: Re: Dual Tarriff digital electricity meter
Post by stocksie on Jul 11^th, 2009, 1:54pm

Oh right,Ive never use a one with an earth only seen them with a live and neutral.
Thanks for the guidance.

Title: Re: Dual Tarriff digital electricity meter
Post by Lectrician on Jul 11^th, 2009, 2:19pm

http://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1096466372#7

Title: Re: Dual Tarriff digital electricity meter
Post by stocksie on Jul 11^th, 2009, 2:38pm

Lec, thats ace thanks.
finally am I right in saying it does need RCD protection a sin the case of T+E cables?
Just spoke to the project manager and he's said the cabling will be able to be boxed in throughout.

Appreciated :D

Title: Re: Dual Tarriff digital electricity meter
Post by Lectrician on Jul 11^th, 2009, 3:14pm

If cables are boxed in, they are usually going to be deeper than 2" from the surface of a wall. If this is the case, no RCD protection is required for the submains.