Storage/convector Heater Circuits?

[Piratepete]

Hi Guys.
Main heating in a new build bungalow is 3 storage+convector heaters and 2 convector heaters. I haven't installed storage heaters before.

I understand that if a fixed heater is rated more than 2Kw, you should put it on a seperate radial circuit (can someone tell me where I've read that?).

The storage heaters are 2.55Kw and 2 at 1.7Kw which could all be supplied on 2 off 20Amp radials to the Offpeak board.
The convectors are 6.25Kw (27 Amps) in total, which could all be wired into their own 32Amp ring to the normal board.
Is this bad practice? Are they all normally on their own radials? If so, would it be acceptable to provide 3 radials for the storage sections but still keep the convectors on their own ring?
Cheers!

 

[gpz900jim]

i would say that its normal practice to wire the storage heaters radially, each heater having its own radial circuit and i cant see why the convectors cant be wired into their own ring main as you suggest

 

[gutterball]

If you have enough spare ways in the board I would run radials to all the heaters. Easier for maintainance,testing ,fault finding etc.

 

[malcolmsanford]

Check out appendix 15 it refers you to regulation 433.1.5 about loading a ring final circuit. One of the recommendations for not exceeding the load current capacity on the cables of a ring is not connecting oven hobs and cookers over 2kw and not fitting immersion heaters, space heating which is NSH or loads of a similar profile.

So the normal installation of a NSH system are individual radials. Protected by a 16amp PD and connecting via a FCU

 

[telectrix]

or, a 32A 4mm radial for each of the 6.25kw heaters.