UK (IMAGES) Connect 20amp Isolator Switch (For Split AirCon) – Need Help.

[MASHK71]

Images Now Included.

Hi there, a new DIY member here based in Hong Kong, where getting reliable electricians can sometimes be a challenge!

I've been finishing off a rennovation project and one of the last jobs is to attach a 20amp isolator switch for an indoor split AC unit (Panasonic).

The electrician who started the installation was unable to finish the job (Covid related!) and getting another one is proving impossible right now. All that remains is simply (ahem) attaching the isolator switch. So I'm wondering if you can point me in the right direction?


The issue - is that there are a few to many wires in the box for it to be clear (to me) which need to be attached to which terminals.

In my set up, I have 4 switches pictured (located either side of a dividing wall between 2 bedrooms and control 4 independent devices.)

Switch 1 - A dimmer switch for the ceiling light in room 1 (switch attached and working normally)
Switch 2 - The 20 amp isolator for the AC unit in room 1 that I need to attach
Switch 3 - A 20 amp isolator for the AC unit in room 2 (switch attached and working normally)
Switch 4 - A dimmer switch for the ceiling light in room 2 (switch attached and working normally)

Please see the attached photos, you'll see that in switch 2 for the AC unit, there are 6 wires, (3 lives and 3 neutrals). 2 of the lives (of different thickness) are paired together and 2 of the neutrals (also different thickness) are also paired together. Leaving 1 live and 1 neutral as yet un-stripped (and from a different inlet port).

In the other 20amp (switch 3) that the electrician attached, there are 2 lives and 2 neutrals running into the corresponding Load and Line terminals and this switch (and it's AC unit) is functioning correctly.

Is it obvious how switch 2 should be wired form looking at these photo's please?

Your help is much appreciated!

https://imgur.com/a1JEeQt

View: https://Upload the image directly to the thread.com/a1JEeQt
(Switches 1 & 2, inside)

https://imgur.com/O2rJfVT

View: https://Upload the image directly to the thread.com/O2rJfVT
(Switches 3 & 4, inside)

https://imgur.com/QTJezSg

View: https://Upload the image directly to the thread.com/QTJezSg
(Switch 3 , wiring)

https://imgur.com/3fcpMGX

View: https://Upload the image directly to the thread.com/3fcpMGX
(Switch 3, terminals)

https://imgur.com/S6hlEnM

View: https://Upload the image directly to the thread.com/S6hlEnM
(Close up of wiring in switch 2 to be attached)

Additional Images for more context
https://Upload the image directly to the thread.com/0LxNgFF (all 4 switches during construction)
https://Upload the image directly to the thread.com/BuqeclN (Switches 1 & 2)
https://Upload the image directly to the thread.com/wtJMrxT (correct wiring for AirCon switch 3)
https://Upload the image directly to the thread.com/yGq46Ex (Switch type front)
https://Upload the image directly to the thread.com/7mWYPNa (Close up of wiring in switch 2 to be attached)

 

[Julie.]

Without knowing where the cables go it is impossible to know for sure!

As a guess I would think that the two thicker cables directly terminated to the two thinner cables are the line and neutral supply, and the thinner ones are something just being supplied permanently. If this is the case, then it is likely that the other two thicker wires are to the ac unit.

If this is the case, you need to connect the two thicker ac unit wires into the corresponding L and N terminals on the load side of the isolator and both the line (thicker and thinner) brown wires currently connected together into the L terminal on the supply side of the isolator, and the same with both the blue into the N terminal.

This is only a guess, really you need to get an electrician to confirm the correct connections, as it could be anything.

One important note, is that all the uninsulated wire - the earths (or correctly cpc) should be connected together - it isn't clear in the photo as some seem to disappear away - you really need an electrician to check this, if they are all the same circuit, then they need connecting together

 

[MASHK71]

Without knowing where the cables go it is impossible to know for sure!

As a guess I would think that the two thicker cables directly terminated to the two thinner cables are the line and neutral supply, and the thinner ones are something just being supplied permanently. If this is the case, then it is likely that the other two thicker wires are to the ac unit.

If this is the case, you need to connect the two thicker ac unit wires into the corresponding L and N terminals on the load side of the isolator and both the line (thicker and thinner) brown wires currently connected together into the L terminal on the supply side of the isolator, and the same with both the blue into the N terminal.

This is only a guess, really you need to get an electrician to confirm the correct connections, as it could be anything.

One important note, is that all the uninsulated wire - the earths (or correctly cpc) should be connected together - it isn't clear in the photo as some seem to disappear away - you really need an electrician to check this, if they are all the same circuit, then they need connecting together

Thanks for your input Julie, very helpful. I'd guess the same as you, though my guess would have been more of a wild stab in the dark than an educated one.

Under the circumstances I guess I'll have to wait until I can get a sparky to take a look.

Thanks