Outdoor lights

awec

Was about to start wiring up outdoor lights, but after turning the downstairs and upstairs lighting fuses off I was surprised to see the cables are still detected as live.

My next attempt is going to be to turn the RCD fuse off, but before I do that I am curious was what this typically will cut in a modern house? Is it going to be outdoor lights and outdoor sockets? All downstairs sockets?

Also, is this likely to be the fuse for outdoor lights? There is no other obvious fuse that I can see.
Cheers!

roady rhodes

Generally speaking in an average house the RCD will control your sockets,immersion,heating pumps etc.


Have you got a shed/garage with a separate sub-board?

awec

roady rhodes wrote: »

Generally speaking in an average house the RCD will control your sockets,immersion,heating pumps etc.


Have you got a shed/garage with a separate sub-board?

No other board no.

meercat

Check that they’re not connected onto the cooker mcb(32amp) by mistake!!!!

I’ve come across this on a few occasions

roady rhodes

Is there an RCBO in board for external lights?


If not their most probably fed from a socket circuit.

awec

roady rhodes wrote: »

Is there an RCBO in board for external lights?


If not their most probably fed from a socket circuit.

I’ve tried turning all the socket circuits off and no joy, still says live.

Tried cooker too.

The only ones I haven’t tried is the mains master one, central heating, smoke alarm and fridge.

There’s nothing that mentions external lights. I wired an external light out the front last year and it was on the downstairs light circuit; these are at the back of the house but I thought they’d all be on the same circuit.

awec

Got sorted, there was an unlabelled fuse :rolleyes:

Conte..

Usually safer to turn off the main isolating switch

It shouldn't be off that long for connecting

awec

Conte.. wrote: »

Usually safer to turn off the main isolating switch

It shouldn't be off that long for connecting

It took me 3 hours!

Mostly because one of the lights was not the last light in the series, so had double the cabling, and had to use some IP44 terminal blocks to reduce the number of cables going into the fitting as the fitting itself only had room for 1 L/N/E.

Conte..

awec wrote: »

It took me 3 hours!

Mostly because one of the lights was not the last light in the series, so had double the cabling, and had to use some IP44 terminal blocks to reduce the number of cables going into the fitting as the fitting itself only had room for 1 L/N/E.

Ok that's way too long for switching off

awec

Actually maybe someone can validate my approach was correct. I had to wire 2 L, 2 N and 2 E. As there wasn’t room for all of those in the fitting, I used 2 x IP44 connector boxes to connect the L and E cables (one for each) and then had only 4 cables coming into the fitting (2 N, 1 L and 1 E).

The connector boxes fitted in the space between the wall and the back plate of the light, so they’re not exposed (but also not in a water tight area since small amounts of water could run down the wall and go through the small gaps).

Also used a dab of silicone to close up the hole where the wires enter the light fixture.

I realised I never taped the connector boxes, but they are the same depth as the gap they sit in so there is no way they can open.

Sound ok?

10-10-20

awec wrote: »

... I was surprised to see the cables are still detected as live.

Can I ask using what device? I've seen ~230v AC being read on a isolated-live conductor due to induction from parallel feeds, so what device were you using to read the state of the line?

Conte..

The old electro-mechanical type voltage testers were good

You.would need an actual supply to drive them


One thing I never understood is proving dead with a 2 wire tester, it assumes a reference, so i'd use a voltage detector as well

awec

I was just using a stud detector on the electric wire setting, placing it directly against the insulated wire and seeing if it beeps. Very rudimentary, probably not at all the right thing to do, but I did numerous tests and some control tests to ensure I was getting the right result.

Could you not have just switched them off?

Conte..

awec wrote: »

I was just using a stud detector on the electric wire setting, placing it directly against the insulated wire and seeing if it beeps. Very rudimentary, probably not at all the right thing to do, but I did numerous tests and some control tests to ensure I was getting the right result.

Ya not an approved method

Its better to pull the main isolating switch sometimes, especially in the absence of proper testing equipment

Conte..

https://www.google.com/amp/s/martindale-electric.co.uk/2015/safe-isolation-procedures-proper-equipment-save-lives/amp/

The old rule is
If in doubt ,short it out.
Don't forget to look away though and used your old snips.
I used to have one called the "Blasting snips"

Conte..

BrownFinger wrote: »

The old rule is
If in doubt ,short it out.
Don't forget to look away though and used your old snips.
I used to have one called the "Blasting snips"

Hazardous tbh doing that

I've had it happen a few times by accident

Bruthal

Conte.. wrote: »

Hazardous tbh doing that

I've had it happen a few times by accident

Yes but if you have as far as is practical, tested power as off, better to then do the snips test than hands on possibly.

Conte..

Bruthal wrote: »

Yes but if you have as far as is practical, tested power as off, better to then do the snips test than hands on possibly.

Can't see it myself but each to their own

Had a bad experience shorting out some busbar by accident