Wiring extractor fan with timer - Does this order look right

[RegB]

Hi, I'm fitting an extractor fan with a timer and I'm considering the best order to fit the components. Does this order look right?

mains>Switched FCU>Fan switch>3-pole isolator>fan

This would have three switches in effect. Any way to reduce the number?
Thanks guys.

 

[GaryMo]

The switched fused spur could act as the isolation for maintenance switch so you could omit the 3 pole isolator if you like.

 

[skenk]

Where is the switched live feed coming from and will this be isolated by the FCU?

 

[GaryMo]

It'll come via the fan switch and yes, isolated by the FCU.

 

[RegB]

Thanks for those replies guys, esp Garymo. It will be handy to cut down the switches by one. Thanks again.
Reg

 

[sparkwright]

Assuming this fan with timer is to be connected so it comes on with the light,
then you only need one switch - a 3 pole fan switch.


I assume you are connecting this to a regular 5/6 amp lighting circuit.

The only other switch you would have would of course be the light switch.

The 3 pole fan switch would be outside the bathroom, I take it?

A 3 pole PULL fan switch is available (made by Ashley).

 

[GaryMo]

Assuming this fan with timer is to be connected so it comes on with the light,
then you only need one switch - a 3 pole fan switch.

He mentioned a fan switch, not coming on with the lights though it I suppose it could mean either.

Also, many manufacturers require overload protection from a 1A or 3A fuse, hence the requirement for a FCU.

He could change his bathroom switch for a DP switch if he wants the fan to come on with the lights and use a FCU so a 3 pole isolator wouldn't be required.

 

[LoveRocket]

Assuming this fan with timer is to be connected so it comes on with the light,
then you only need one switch - a 3 pole fan switch.

He mentioned a fan switch, not coming on with the lights though it I suppose it could mean either.

Also, many manufacturers require overload protection from a 1A or 3A fuse, hence the requirement for a FCU.

He could change his bathroom switch for a DP switch if he wants the fan to come on with the lights and use a FCU so a 3 pole isolator wouldn't be required.

Is it ok to have power from two different circuits in the same DP switch? (is there anything in the regs about it, risk of someone only isolating one circuit etc)

 

[securespark]

Why two different circuits?

 

[LoveRocket]

Sorry, I read more in to that than had been posted. I'll ask a new question then:

Is it OK to have a DP switch switching a light from the lighting circuit and also a fan from a FCU from a socket circuit?

 

[electronicsuk]

Sorry, I read more in to that than had been posted. I'll ask a new question then:

Is it OK to have a DP switch switching a light from the lighting circuit and also a fan from a FCU from a socket circuit?

As long as the switch is suitably marked then I would say yes. However, if you read through the previous posts properly then you will see that nobody is suggesting doing that. The FCU would be fed from the lighting circuit.

Also, use of a DP isolator as you propose would only allow you to isolate the line conductor of each circuit, so not a lot of use for servicing purposes!

 

[sparkwright]

Sorry, I read more in to that than had been posted. I'll ask a new question then:

Is it OK to have a DP switch switching a light from the lighting circuit and also a fan from a FCU from a socket circuit?

No one has suggested running a fan from a FCU from a socket circuit. The FCU is (presumably) connected to the same lighting circuit, as is there if the fan requires protection at 3 amp. Some manufacturers like to ask for it.

 

[LoveRocket]

I did say it was a new question after I realised the OP wasn't on about that.

Why would it be no good for servicing?

Socket ring-------FCU----DP switch----Switched live to fan
(and from same) FCU------------------Live to fan

So with the FCU off everything's safe, right?

 

[electronicsuk]

I did say it was a new question after I realised the OP wasn't on about that.

Why would it be no good for servicing?

Socket ring----FCU----DP switch----Switched live to fan
. \------------------Live to fan

So with the FCU off everything's safe, right?

Because you want to be switching the live conductors, not just the line conductors.

 

[LoveRocket]

A double pole FCU then.....

But there's no regs issue preventing the two circuits going through (different poles of) the same switch though?