Rookie electrics question - turning the power off

[simondyntDBeK]

Hi folks,

I'm fitting a light in the loft. Whenever I do any electric work I always shut everything off - all the circuit breakers and the main one too.

Am I right in thinking that if I'm fitting the light to the light circuit, I can just switch off the breakers for the lighting circuit and leave the rest of the power on? (therefore enabling me to have an electic power light in the loft run from an extension)

I think I know the answer is yes but wanted to run it past an expert!

Ta

Simon

 

[ColJack]

providing that the lights are not on an RCD ot the RCD side of a CU then it should be fine..

be absolutely sure you are cutting the right wires though and that they are "dead" before cutting them.. ( get a non contact volt stick from B&Q, read the instructions carefully and test on a known live cable first.. )

 

[simondyntDBeK]

Thanks ColJack - will look into the volt stick thingy!

Ta

Simon

 

[JohnD]

Always treat every wire as potentially live until you have proved (by testing) that it is not.

Recommended method:

find the terminals.
Test them with your meter that they are live
Turn off the isolator
Test with your meter that they are dead
Turn on the isolator again
Test again that they are live
Turn off the isolator
Test again that they are dead
Start work.

Why turn back on you ask?
It verifies that your meter is not showing "dead" just because the meter has failed, or the test lead come loose, while you were working. You are also verifying that you are turning on and off the correct isolator, just in case someone else is working on a nearby circuit, or there is a timeswitch or thermostat that has by chance turned the circuit temporarily off.

 

[Qedelec]

...and one other bit of advice, make sure you link into a feed cable as I have been called to more than one instalation where the client has connected into a switch wire by mistake.

 

[plugwash]

oh and always hold cutting tools by an insulated part (ideally use fully insulated tools but that may be a little impractical for the diyer) test both sides of a cut for live after cutting in case of borrowed neutrals.