airing cupboard wiring query

[arbitrary]

A have a T+E cable running up the back wall of the airing cupboard feeding two mains outlets in the loft. It’s in turn fed from a fused spur attached to the ring main.

I would like to install a shower pump (220v) and a low voltage transformer (for 24v supplementary underfloor heating in the bath) in the airing cupboard and control them with timers such as http://www.timeguard.com/products/t...7-day-electronic-immersion-heater-timeswitch. Any suggestions on how I can tap into the T+E? One would appear to be to use two single gang flex outlets in double gang surface mount box to feed each of the timers. Any comments or other ideas welcomed.

 

[flameport]

You could use 2 flex outlets, but:

Why do you want a shower pump on a timer?

Surely the underfloor heating is supplied with a timer/thermostat device to control it?

 

[Chri5]

A have a T+E cable running up the back wall of the airing cupboard feeding two mains outlets in the loft. It’s in turn fed from a fused spur attached to the ring main.

So you are saying that the cable comes from a 13A fused spur and is used by either 1 x twin socket, or 2 x twin sockets ?

I would like to install a shower pump (220v) and a low voltage transformer (for 24v supplementary underfloor heating in the bath) in the airing cupboard and control them with timers such as http://www.timeguard.com/products/t...-7-day-electronic-immersion-heater-timeswitch .

What is the load / wattage required for the 2 devices AND the two clocks ?

What is the use of the sockets in the loft ? Is it a play room or 'just' a loft with junk in ?

If we work to the sensible design considerations (not the true potential levels) then that cable can take 13A of load.
A fused spur on a fused spur on a fused spur is a very messy thing, and I would never fit such.

That said, you could break the cable so the pump has a 3A fused spur, the heating (only if the load is okay!!!) 5A fused spur and a modest 5A fused spur for the socket(s) in the loft.

The total rating is then limited to the 13A design ability of the cable. The cable must be 2.5mm TE from the spur socket on the ring and there could be load limitations due to cable route and length.

 

[arbitrary]

Chaps, thanks for your posts.

Yes, the T+E is fed by a 13A fused spur and feeds a twin socket in a storage loft (v rarely used, perhaps 1 hour spread over a month, max load 1000watts).

Shower pump is 2.8A continuous. Transformer is perhaps 1A if that. The clocks are 6 watts each.

In the extremely unlikely event that all consumers are switched on at once I reckon max load is ~8.5A.

The underfloor heating is mylar foil under the tiles just enough to take the cold edge off (Enerfoil). There's no thermostat as it only uses about 200 watts total and raises the floor temp about 12-15 degrees from ambient. It could easily be left on 24/7 but that seems like a complete waste.

I'd like the pump on a timer as it also feeds the basin taps in that same bathroom and late at night the noise of the pump running could be enough to wake light sleepers. Flw without the pump shuld be enough for late night uses.