Help to identify wiring in light switch

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SushiCat

1 post

Wannabe Geek

#274451 22-Aug-2020 22:23

Hey folks! First time GZ user here, but this looks like a great community to collaborate with on home projects.

My project at the moment is to replace all my old light switches with fancy new smart switches.

In order to do this, I first need to identify the Load, Live and Neutral wiring so that I can put these in the right place on the new switches.

The image I've attached shows how the switch is currently wired (it's a basic single light switch). There is one wire going into the terminal labelled '1' and two going into "C". Then there are the 3 black wires just joined together, not attached to anything.

My thoughts were the black wires were the neutral, the 'C' wires were the Load, and the '1' wire was the Live... But this didn't seem to work.

I didn't want to blow anything up so I thought I'd seek help before going any further.

Any thoughts? It could be that I don't actually have a neutral line, and so that'd mean I can't use this particular smart switch, (I just bought one to test it out before buying a whole house worth).

Cheers!

SomeoneSomewhere

1802 posts

Uber Geek

Lifetime subscriber

#2547896 22-Aug-2020 22:35

Black is almost certainly the neutral.

C is probably the feed; one will be feed in from the board or previous switch, the other feed out to the next switch.

1 will be line out to the light.

Please ensure you read NZ ECP 51 and follow safe working practices.

sparkz25

750 posts

Ultimate Geek
Inactive user

#2547906 22-Aug-2020 23:23

SomeoneSomewhere:

Black is almost certainly the neutral.

C is probably the feed; one will be feed in from the board or previous switch, the other feed out to the next switch.

1 will be line out to the light.

Please ensure you read NZ ECP 51 and follow safe working practices.

What @SomeoneSomewhere said.

Also it looks like those need a tidy up as the switch to light wire should be doubled up and the feed looks to have been rather tight and crushed the copper some what as it looks like its going to break where the screw has been done up.

That is just how I was taught and how I have wired light switches for years.

Goosey

2829 posts

Uber Geek

Subscriber

#2547996 23-Aug-2020 10:54

That doesnt look like it was the orignal sparky's work.... perhaps someones done a backyard job on this before....

Id suggest getting a sparky in to help.... I wouldnt be concerned about blowing somthing other than yourself or someone......including house.

raytaylor

4014 posts

Uber Geek

Trusted

#2548043 23-Aug-2020 11:22

On the light switch, C would be common, which gets bridged to 1 in switch position 1 (or) common is bridged to 2 if the switch is in position 2.

Solution: You could just use a multimeter to test which one is which.

Put the wires back into the light switch (so its not as exposed) and then turn on the breaker. Use your multimeter in AC mode between the black and one of the red wires to see which red one gives you voltage.

Ray Taylor

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Spreadsheet for Comparing Electricity Plans Here

Daynger

435 posts

Ultimate Geek

#2548108 23-Aug-2020 12:45

One of the major hurdles of homeowners doing their own work is all in one word, competent.

ECP51, the homeowner wiring rules state that to undertake electrical work around your own home you must be competent, unfortunately most people dont work out they are not competent until they have a mess of wiring they cannot figure out or have had a nice zap.

If you are asking such a question here about which wire is which i would suggest that you are not competent to do the job, nor do you have the test equipment that will tell you which wire is the live and which is the light as it could be either, a feed in and feed out plus light wire or a feed in and two separate light wires out.

The good news is you can learn how to become competent by searching basic switch wiring diagrams, buying a multimeter and learning on a basic switch such as this one you have opened (just wait until you open a 6 gang switch with intermediates, two ways and dimmers), please, do the learning bit first as if you get it wrong you could lose your house or your life.

Also check that your fancy new smart switches are compliant in NZ many arent and if they decide to assplode your insurance company may not pay out on the smoking ruin that was your home.

My first bit of advise for anyone working with electricity is: You cant see it coming and it always sucks when it gets you.