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clarob
Jul 20, 2008, 05:18 AM
Hello.

I'm fitting a timer onto my immersion heater so it'll run on the cheap rate electricity at night.

It fits on the cable between the switch (just an on/off switch) and the mains.

Looking at the connections where I'll join up the ends of the cable it has five connections in this order (left to right)

SL N N L E

Where the first two (SL and N) are the live and neutral going out to the switch (and on to the tank) and the second two are the neutral and live coming in from the mains. The last one is the earth connection and is set apart from the others a bit (the others are marked by arrows showing which direction the current is going in)

But, if I cut a cable with 3 wires (L, N and E) then I'll have two Earth wires and nowhere to fit one of them?

The instructions make no mention of this - I think they assume it must be obvious. It's not! (not to me anyway... )

Help!

Thanks...

tkrussell
Jul 20, 2008, 05:29 AM
You can use a short piece (pigtail) of earth wire and marrett (splice) it to the two earth wires, and insert the one pigtail into the earth terminal.

clarob
Jul 20, 2008, 05:33 AM
Wow that was quick!

Would that be the same thing as putting the two earth wires into the earth terminal?

tkrussell
Jul 20, 2008, 05:39 AM
Yes, this is done often when more than one core (wire) needs to connect to a terminal rated for only one core.

clarob
Jul 20, 2008, 05:42 AM
Fantastic. I'll do that then
Fingers crossed I don't blow up the house!

Thanks

Credendovidis
Jul 20, 2008, 05:50 AM
I don't precisely understand your problem.
Why don't you install the timer just directly to the on/off switch? : you need to hook up to the following three wires (with a four wire cable) :

1 - SL hot switched
2 - N neutral switched
3 - N neutral in
4 - L hot in
5 - E earth

Your timer switch should be connected as follows :

1 - SL hot switched : connect to timer in. Wire that went to tank connect now to timer out.
2 - N neutral switched to timer neutral and to tank neutral.
5 - Earth to all earth wires (a common connection to all).

Note : wire 1 - SL hot switched should be cut, with the timer switch in between (i.e. the timer interrupts this wire) This last connection is a new separate connection point.

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