Fitting External Security Light to Mains

Hi, just fitting an external 150W security light. Using 1mm 3 core insulated wire. The wire goes through the porch into the corner where the mains box is (quite old box -but fitted with circuit breakers)

I have got to the mains box. I,m intending to fit to the mains onto a ciruit breaker that is spare (from when there was power to an old garage, now demolished).

1. My wire from the light is much smaller than mains wire.
2. Unsure whether this is OK
3. the Earth, Neutral wires go to seperate terminals with the Live going into the circuit breaker

My question is

1. Should I be doing this ?
2. The security light instructions said to use a 1mm wire - but is this too small if fitted directly to the mains?
3. Any suggestions - do you think I should get an electrician in?

M.Thanks

In my opinion I think you would be better off getting in a suitably qualified electrician. Get yourself at least 3 quotes if possible.

I'm planning on doing something similar myself. This is what I've found out:

You can connect 1mm wire straight into a circuit breaker of 10A or less. Since your light needs less than 1A, a 6A MCB or smaller is best. The earth and neutral connect to separate terminal blocks when you're using a single pole MCB (which is normal).

Here are some other things I've read on this site:
1) You may be required to fit a double pole isolator, even if the light uses a PIR. Search for "Chapter 46" on this forum.

2) You might want to protect the outside light with an RCD, which could be done by using an RCBO instead of an MCB.
//www.diynot.com/forums/viewtopic.php?t=11124

3) You should use PVC conduit when going through the wall (if it is a cavity wall) as existing or future cavity wall insulation may react with PVC wire.

If you're fitting new wiring then you must notify building control and pay a fee (see Part P on this site's Wiki). For a small piece of work like this it is probably cheaper to get an electrician to wire it up for you.

Any corrections or additions to what I've put are very welcome!