Wiring Instructions for an Immersion Heater Controlled by X10

[paul10june]

I intend to replace an immersion heater switch with one that can be controlled using X10 home automation.....BUT I have a problem!

The wiring on the existing switch consists of Red (live), Black (neutral) and earth.

The new switch seems to be rather different, having inputs as follows;
Neutral, Load and Live

i am suspecting my existing set-up is for 2 core plus earth, whereas the switch is for 3-core plus earth.

is there any way i can easily wire up the new switch using existing wires???

[AlBags]

You're not explaining very well .. Where is the power coming from?

Assuming the original cable is of the correct core size and working with the original thermostat .. and is remote from the thermostat:
First thing is to work out how the original switch is wired in exactly. If it's taking a live supply, and passing it to immersion/thermostat, it must be passing the load supply up the neutral cable to the thermostat IF there are no other cables. The immersion must be supplied with neutral at it's location.
The new type switches/timers rely on an input supply and pass the supply to the load output. Earths are parked and connected together, and neutrals inter-connected in the switch body usually (as in a Horstmann Economy 7 timer)
You will have to run a supply cable to keep existing switch location.

[paul10june]

Thanks Albags.
Sorry I am not explaining - I think that is part of the problem, I don't really understand.

Let me try again.

The imersion heater and thermostat are in place and wired up. The wire from the switch to the heater/thermostat is a standard heat proof cable. It has 3 cores - red, black and green. The current wiring is to a simple on/off switch, which has 6 terminals. Therse are :
Live in (to which is connected the red wire from the house mains)
Live out (to which is connected the red wire leading to the immersion heater)
Neutral in (to whiuch is connected the black wire from the house mains)
Neutral Out (to which is connected the black wire leading to the immersion heater)
Earth (to which is connected the earth wire from the house mains)
Earth (to which is connected the earth wire leading to the immersion heater)

The existing wiring is similar to that you would expect in a standard 13amp plug socket.

So my problem is this:

The new X10 controller has Only 3 connections to which somehow I need to attach 4 wires (excluding the earths which I appreciate have to be connected separately).


Now as I believe I need to wire would be this:

1. Connect the 2 live wires using a connector as there is no terminal on the switch
2. Connect the red from the mains to the "live" terminal in the switch
3. Connect the red to the immersion heater to the "load" terminal in the switch
4. Connect BOTH the black wires (one from the mains, the other to the immersion) together in the switch terminal marked Neutral in the switch

Will this work or will there be a problem?

Is this a little clearer?

Paul

[paul10june]

EEEK! Sorry. typo. my post should have said connect the two earth wires!! NOT the two live wires. Sorry.

[TonyV]

Paul - if you are asking and with all respect you don't understand electricity - get a Spark in to wire it up - can be dangerous - you might make it work, but not necessarlly safely

[Hymie]

I believe that your proposed connections listed 1 – 4 (with the noted correction to 1) to be correct.

Although somewhat unusual, the controller has only one neutral terminal (for connection of the neutral in and out), with the incoming live connected to the Live terminal and the immersion live connected to the Load terminal.

I am somewhat surprised that the installation instructions for the controller do not spell this out clearly – I trust that the controller is rated at 3kW for mains voltage.

[paul10june]

Thanks Hymie, the wiring worked fine once I understood the neutral isn't switched. The timer is rated 3000w and seems to work nicely on the X10 signal. Believe it or not, there were n o instructions in the box, nor on the website of the supplier!

[AlBags]

Glad that worked out!