My house (built in the 1960s in New Zealand, if that matters) currently has a single bulb by the front door which I'm looking to replace with a security light. The light is controlled by a switch on the wall by the front door.

I removed the existing bulb and found that there were 2 wires connected to it: one black and one red (refer to image below).

light fixture wiring

After deciding how I was going to install the security light, I bought one. However, after reading the instructions, I found out that I need to connect 3 wires (live, earth, and neutral) to the light. A bit of Googling shows that this is needed for the IR sensor.

I was unable to find out what I should do about this though. Everything I've read about a red and black wire insists that there is also a white wire (there isn't, I've checked). Additionally, the security light mentions that the wire colours should be blue (N), green/yellow (E), and brown (L). These obviously aren't the colours of my wires so I'm not even sure where to start.

I'm hoping someone here can shed some light on how I can (or even if I can) install the 3-wired security light in the place of a 2-wired (not security) light.

2 Answers 2


Because New Zealand is harmonized to AU standards, which are based on old UK standards, not North American standards. (though AU uses North American junction box form-factors, and do not use the ungainly UK plugs.) Your wiring is:

  • Live: Red (generally)
  • Neutral: Black
  • Ground: Yellow w/ green stripe... with green and bare also acceptable due to world harmonization

The "rest of the world" has largely harmonized to:

  • Live: Brown
  • Neutral: Light Blue

For reference, North America has

  • Live: Black or any color not otherwise assigned
  • Neutral: White or gray

North American stuff may fit your boxes, but it is not safety certified there, and is only rated for half the voltage.

I would expect items manufactured to comply with AU/NZ safety standards to have domestic wire colors. Be wary of cheap items sold mail-order, which in all likelihood do not comply with safety standards.

  • Here in the USA, the ground is green/yellow, green, or bare. Live wire is black, and neutral is white.
    – Proxy303
    Oct 23, 2021 at 21:03
  • The light wasn't purchased from overseas or anything, so I honestly would've expected the wire colours to be correct. It was sold from a reputable NZ hardware store
    – JolonB
    Oct 24, 2021 at 0:22

This isn't a full answer but I hope can help. My perspective is from Australia so hopefully close enough. My place (built 1934, so I assume the old wiring is 50s or 60s) also has old red/black wiring in a few places. The practice then was to run the earth as a separate, bare (uninsulated) stranded wire. It seems to always have been close by the live and neutral. It was secured to timbers with broad flathead nails of some sort. It was branched by intertwining and soldering. Your photo seems to be looking up into the eaves. Lighting wires will have been run through the roof space. Can you get up into that space? Be careful, as there may be exposed, and deadly live wires. The correct practice is to turn all power off before venturing into the roof. Final note, even if you have a safety switch, the RCD is sometimes not covering the lighting circuit. If you're not 100% comfortable with any of this, get a sparky.

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