Join spur into ring?

[Nigel Molesworth]

Would you like to explain the difference, electrically?

[zikkimalambo]

Surely no more so than if it is added to the ring at that point?

Either way, to come back to the op's question, I concur with Andy Wade. Just change it to a double and stick with the 2.5 T+E (E&OE) Maybe also check the connections at the other end are nice and tight.

[Nigel Molesworth]

I should have said, and this is very relevant, the distance is about 1 metre! I just want to take the socket below the work top.

In the circumstances, I thought that doubled 2.5mm T&E would be OK, but obviously 4mm or 6mm would be neater.

I take David's point about a "little knowledge", but I asked the question originally because I was aware that it was unconventional.

[David Hansen]

On Tue, 24 Jan 2006 12:28:45 +0000 someone who may be Nigel Molesworth wrote this:-

The existing cable may well be fine. However, only one of us can see where and how it is installed, you. Only you can say about ambient temperature, insulation, duty cycle and so on.

[Nigel Molesworth]

It's in an insulated timber partition. I don't know about the duty cycle, but SWMBO is *supposed* to try to use the WMC and TD at different times at night, during the Economy 7 periods.

Having looked further, I've now realised that I can't put the socket where I wanted to anyway; I need to use timeswitches which would foul the bottom of the basin.

I think my best bet is to use the existing single spur with a 2-outlet socket plugged in via a flex, and mount this where the timeswitches are accessible. If the 13A fuse blows, it means I need a re-think.

[robkgraham]

Following through this thread, I was wondering why no one had thrown up the part pee bogy. Having seen a mention of a 'basin' I'm even more surprised this hasn't been mentioned. I'm prepared to be educated but isn't his just what part pee proscribes as the modification is taking place in a kitchen or equivalent area ?

Rob

[Fred]

Isn't he just replacing a socket with a "near" equivalent? Saves using a 2 into 1 adapter.

[ARWadsworth]

Utility rooms are Part P exempt.

Adam

[Nigel Molesworth]

As are kitchens, if you have a large stock of red and black cable ;-)

[ARWadsworth]

Will it not self destruct in April?

Adaml

[Owain]

You don't have to have the timeswitches in the same place as the socket, indeed I wouldn't recommend most plug-in timeswitches for sustained 13A loads. You can use wired-in timeswitches anywhere on the (spur) circuit.

Owain

[John Rumm]

And in some circumstances would actually have the advantage that 2 x

2.5mm^2 would have a lower earth fault loop impedance than a single 4mm^2 as a result of the greater total CPC CSA.

[Andy Wade]

Emphatically seconded. Also the idea of using a flex and extension socket will lead to grief. Feeding both appliances through a single 13 A fused plug really isn't on at all.

[Nigel Molesworth]

I started a new thread on this very topic.

Do you know where I can get an independent two-channel timer with 13A contacts, preferably (although not essentially) the same shape as a double 13A socket?

[David Hansen]

On Tue, 24 Jan 2006 16:32:25 +0000 someone who may be Nigel Molesworth wrote this:-

Does the cable have thermal insulation on both sides? Does the ring main cable pass through similar insulation?

I wish more washing machines and driers had lights to indicate when the heating element is on. However, I suspect that you will find my guesses are reasonably close to how your machines work.

I take it that the machines do not have built in timers and that their leads are not long enough to reach a high level socket (or this would not be approved by the boss).

This is what I would do for the situation as currently outlined:

1) fit two switched fused connection units in the ring main (these are often cheaper than the alternatives). These could be flush mounted in a metal box that can take two single accessories. If you want them surface mounted then MK make a suitable box that their accessories fit nicely. These would be at high level. If the existing socket is not used a lot I might replace it with these, otherwise I would put the new bits near the socket to make it easier to modify the ring main. 2) run a cable from each connection unit to a time clock. These would be at a suitable location depending on your needs. Time clocks that fit on a single box are available. They are more expensive than the plug in sort, but better made. If mounted together on a box that takes two single accessories, make sure that the time clocks don't have a bottom plate that makes them a little wider than a single accessory (some do, some don't). 3) run a cable from each time clock to an unswitched socket in a suitable place to plug the appliance in. 4) test and energise.

5) mark the sockets, time clocks and connection units so it is clear that they are not normal sockets.

The size of the cable from the connection unit will depend on the precise installation details. 1.5mm will probably be fine, but only you know the kitchen.

If the cables are to be buried then beware of the acceptable zones for wiring and what one does if the cables are not in these zones.

[Nigel Molesworth]

I had come to the same conclusion as you, but I was going to use plug-in timers, then go *into" a connection unit to get back to cable.

Reason for this strange arrangement is that I can't find any non-mechanical fixed timers that switch 13A. Any suggestions?

[David Hansen]

On Wed, 25 Jan 2006 14:14:34 +0000 someone who may be Nigel Molesworth wrote this:-

The timers I have seen for fixed wiring have all been mechanical, but I have not seen that many and the last new one I saw was a year or two ago. I would suggest the makers of central heating controllers might make other types of time clock.

[Owain]

These ones include the switch and fuse. 24h and 7d versions. 3kW resistive load, 6A inductive.

FST11 is a 24 hour fused spur timeswitch for controlling ... washing machines and dish washers.

one doesn't