Confused by Wiring when swapping out a bathroom extractor fan.

[rickmd]

I have an extractor fan in the bathroom ceiling which comes on when the ceiling light is switched on. The fan also has its own isolation switch. I need to swap the old fan out for a new one.
I'm confused about colour coding in the wiring. As you can see from the photos tbe exiting wiring from the isolation switch to the fan uses Brown Neutral and Earth (tagged with brown tape) however the new fan uses Grey Black and Bown. What is the order to match these up? I'm assuming blue goes to the Grey wire but not sure about the other what goes to Brown and Black.
Kindest regards, Rick

 

[trojanhawrs]

Blue to neutral, brown to L1 and brown sleeve to L2. If the fan runs on after you turn the light off, it's wired correctly. If the fan stops when you turn the light off, swap L1 and L2.
Be careful in case the isolator is not isolating both the lives.

 

[JohnD]

Brown Neutral and Earth

You mean brown, blue and green/yellow.

You cannot deduce the purpose of these wires from their colour.

It looks like a flex. Where is the other end connected?

 

[rickmd]

You mean brown, blue and green/yellow.

You cannot deduce the purpose of these wires from their colour.

It looks like a flex. Where is the other end connected?

Correct, I meant brown, blue and green/yellow (with brown tape)

It looks like flex but the other end is connected to the fan isolator switch.

 

[rickmd]

Blue to neutral, brown to L1 and brown sleeve to L2. If the fan runs on after you turn the light off, it's wired correctly. If the fan stops when you turn the light off, swap L1 and L2.
Be careful in case the isolator is not isolating both the lives.

Thank you for your advice, much appreciated.

 

[JohnD]

Correct, I meant brown, blue and green/yellow (with brown tape)

It looks like flex but the other end is connected to the fan isolator switch.

If it's accessible, you could replace with three-core and earth.

Do you have a 3-pole isolator?

 

[rickmd]

Blue to neutral, brown to L1 and brown sleeve to L2. If the fan runs on after you turn the light off, it's wired correctly. If the fan stops when you turn the light off, swap L1 and L2.
Be careful in case the isolator is not isolating both the lives.

I have wired it up as you suggested. I did have to snap off a small plastic tab that was blocking the L1 terminal (you can just about see it in the photo ) to connectvgge wire.
The fan continues when the light is switched off however it continues and doesn't time out. I've obviously done something wrong? Should I have conected the L1 at all?

UPDATE

I've mistakenly bought a non timer version which accounts for why it wasn't timing out. Its permanently on where the light of on or not. I can only switch it off at the isolation switch. Annoying.

 

[Sparky3]

The green and yellow wire is an earth wire and should NEVER be used as a live wire.

You need to change the flex for 3 core and earth.

 

[EFLImpudence]

The green and yellow wire is an earth wire and should NEVER be used as a live wire.

The green and yellow wire should be an earth wire and should NEVER be used as a live wire.

 

[Sparky3]

The green and yellow wire should be an earth wire and should NEVER be used as a live wire.

Thank you Mr Pedant.

Green and yellow is denoted as earth and prohibited from any other use.

 

[EFLImpudence]

Thank you Mr Pedant.

Just making it clear for those who might not know.

Green and yellow is denoted as earth and prohibited from any other use.

Except in this case it is not.

 

[Sparky3]

Except in this case it is not.

It is still forbidden, just some numpty has ignored the rule.

 

[Jurassicspark]

Green and yellow is denoted as earth and prohibited from any other use.

You can't forget about bonding

 

[EFLImpudence]

It is still forbidden, just some numpty has ignored the rule.

It was only recently forbidden so likely not so when the fan was fitted

 

[trojanhawrs]

I have wired it up as you suggested. I did have to snap off a small plastic tab that was blocking the L1 terminal (you can just about see it in the photo ) to connectvgge wire.
The fan continues when the light is switched off however it continues and doesn't time out. I've obviously done something wrong? Should I have conected the L1 at all?

UPDATE

I've mistakenly bought a non timer version which accounts for why it wasn't timing out. Its permanently on where the light of on or not. I can only switch it off at the isolation switch. Annoying.

Yeah, in that case just disconnect the brown wire and wire it into a choc block, you can use the fan with the light until you get the right unit