Fan Replacement

[Hughie]

I am replacing a (mechanically) worn-out bathroom ceiling fan - a straightforward like-for-like replacement. The fan is not a timer type and is wired into the (5 amp MCB) lighting circuit in the usual way via a three-pole isolator (only 2 poles used). There is no separate fuse for the fan circuit but the manufacturers stipulate the fan should be protected by a 3 amp fuse.
Is this normal? The circuits in the wiki show no separate fuse although most of the small bathroom fans I looked at require 3 amp max circuit.
What should I do?

Hughie

 

[sparkyspike]

As you are only switching two poles, replace the 3 pole isolator for a 13A DP switched fused connection unit with a 3A fuse in it. Manufacturers do sometimes specify a 3A fuse.

 

[Hughie]

I did consider that but would the change to the wiring make the job notifiable under Part P?
Also it is not my house but belongs to ageing in-laws and a straight swap would put the FCU would be about 7 feet off the floor which is not good for elderly folk.

 

[Taylortwocities]

But that switch/FCU is only there to isolate the fan for maintenance so they should not need to touch it.

I would say this work is not notifiable as its a maintenance replacement. You could "accidentally" break the 3 pole isolator and replace it with a 3A fcu if you really wanted to!

 

[ColJack]

manufacturers only refer to a 3amp fuse in case you feed it from a FCU..
the 2 fuse sizes available are 13A and 3A, so they stipulate 3A to save having to put 1.5mm cables internally...

before anyone points out 5A fuses, they are a non standard size and are not recognised..

 

[ericmark]

manufacturers only refer to a 3amp fuse in case you feed it from a FCU..
the 2 fuse sizes available are 13A and 3A, so they stipulate 3A to save having to put 1.5mm cables internally...

before anyone points out 5A fuses, they are a non standard size and are not recognised..

Although I would have agreed with ColJack a few months ago someone else had same problem and rang manufacture who said a 3A fuse was required which in their case was real problem as it also had run-on and BAS did a circuit showing use of duel pole light switch.

So I would replace isolator with a switched spur this also means if the fan goes faulty the fuse should blow before the whole lights fuse although when MCB's are used unlikely this will happen in practice.

I have never phoned manufacture myself and I will admit I was some what surprised when they reported the reply.

Personally in my own house I would not worry and I would just change and take the chance if it goes faulty I may not get replacement under guarantee.

 

[Hughie]

Thanks all - I think I will go with the FCU, though Ericmark's idea is tempting too. H