wiring for bathroom extractor

[johnjo]

Hello,

so Ive got a cable that was removed from the old extractor, it is a grey cable wich has grey/black/brown. The new extractor takes a live and neutral. Wiring is recent, within the last 10 years. What do I do?

I know I should get someone in, but don't have the ££, so hoping you can point me in the right direction.

help appreciated, thanks

 

[Octopus]

Unless you can confidently confirm which of the 3 cores are live, neutral and switched live you are in to the "bang" test.....

 

[Resu]

You've answered your own question in a way. Simple enough job, using your tester identify permanent live, switched live & neutral and connect it up!

EDIT: beaten to it!

 

[Pete999]

Hello,

so Ive got a cable that was removed from the old extractor, it is a grey cable wich has grey/black/brown. The new extractor takes a live and neutral. Wiring is recent, within the last 10 years. What do I do?

I know I should get someone in, but don't have the ££, so hoping you can point me in the right direction.

help appreciated, thanks

Is that a C&G b===== All? where are you situated?

 

[johnjo]

You've answered your own question in a way. Simple enough job, using your tester identify permanent live, switched live & neutral and connect it up!

EDIT: beaten to it!

Ok, so 1) how do I identify them ( I assume live will show up on my voltage test pen ) but how do I dentify neutral and switched live?
and 2) if ive identified them, I still have 3 neutral , live and switched live on the cable, and just neutral and live on the fan, so what goes where?

cheers

 

[Taylortwocities]

A voltage test pen will not help you here.
Voltage pens won't identify the neutral and they'll light up if you sneeze at them.
You need a two-probe voltage tester, or a multimeter (£6ish from lots of places).

 

[davesparks]

Ok, so 1) how do I identify them ( I assume live will show up on my voltage test pen ) but how do I dentify neutral and switched live?
and 2) if ive identified them, I still have 3 neutral , live and switched live on the cable, and just neutral and live on the fan, so what goes where?

cheers

Do not use a 'voltage test pen' they can give misleading results and could put you in A very dangerous situation.
To identify the conductors you need a proper tester, a regular two pronged voltage tester with a continuity test function is all you need.
Once you have identified them you will need to make safe the conductor which you no longer need, ideally by disconnecting it at the other end of the cable.
Which conductors do you need for the new fan?

 

[davesparks]

A voltage test pen will not help you here.
Voltage pens won't identify the neutral and they'll light up if you sneeze at them.
You need a two-probe voltage tester, or a multimeter (£6ish from lots of places).

A cheap multimeter almost certainly won't be safe to use, or approved for use, on mains electricity.

 

[Taylortwocities]

A cheap multimeter almost certainly won't be safe to use, or approved for use, on mains electricity.

Really?
It may not comply with GS38, but most of those have 500V AC voltage ranges.
If they are unsafe why are they on sale in every DIY store in the country?? Do you need to take your concerns to Trading Standards??

Edit. Just had a look at the spec of a couple of cheap ones. They all comply with the EN61010-1 safety standards.…

 

[Phil Thompson]

The old fan was a timer model hence the permanent live, the replacement fan you have is standard so only requires the switched live, if you require the fan to remain running for a duration after lights off, this will no longer be available.

The fan will only run when the lights are on.

I'd suggest you swap it back for a timer model as the extra run time after lights off is necessary to remove the humidity after showering to avoid black mouldy areas as well as the old toilet smells lol

 

[davesparks]

Really?
It may not comply with GS38, but most of those have 500V AC voltage ranges.
If they are unsafe why are they on sale in every DIY store in the country?? Do you need to take your concerns to Trading Standards??

Edit. Just had a look at the spec of a couple of cheap ones. They all comply with the EN61010-1 safety standards.…

Without looking inside for myself and seeing how good the protection is I wouldn't be sticking them probes near a mains supply.

There's plenty of good videos on YouTube of these things being opened up and showing how bad the protection/fusing can be.

 

[davesparks]

The old fan was a timer model hence the permanent live, the replacement fan you have is standard so only requires the switched live, if you require the fan to remain running for a duration after lights off, this will no longer be available.

The fan will only run when the lights are on.

I'd suggest you swap it back for a timer model as the extra run time after lights off is necessary to remove the humidity after showering to avoid black mouldy areas as well as the old toilet smells lol

How do you know that the new fan requires the switched live and not the permanent live? He hasn't said whether the new fan is standard or has a humidity or pie sensor function

 

[Phil Thompson]

Hopefully he tells us if it is then lol

 

[johnjo]

The old fan was a timer model hence the permanent live, the replacement fan you have is standard so only requires the switched live, if you require the fan to remain running for a duration after lights off, this will no longer be available.

The fan will only run when the lights are on.

I'd suggest you swap it back for a timer model as the extra run time after lights off is necessary to remove the humidity after showering to avoid black mouldy areas as well as the old toilet smells lol

this sounds like the right answer - i'll take the unit back and get a timer one.

Many thanks for all the comments on here - electrics are a bit scary when you're guessing but, at the end of the day, it cant be that hard cant it? I've known a few electricians and TBh they haven't been contenders for mastermind. ( i'm winding you up )

thanks, will update once i've got the timer model.

 

[johnjo]

Hopefully he tells us if it is then lol

So I switched the fan for one with a timer, identified that the brown one was live ( by licking it ) . the black and grey had no power even when switching the lights on. So I went for brown->live, black->neutral, grey->switched live. Nope. So I then went for brown->live, grey->neutral, black->switched live, bingo.

thanks for the assistance