Extractor fan

[andyj941]

Hi I've got to replace a damaged switch in the hall for the extractor fan in the bathroom on the other side of the wall. The one that's on there at the moment has 2 lives and 2 neutral cables coming into it and 1 of each going out again, plus a couple of earths.

Picked up http://www.diy.com/diy/jsp/bq/nav.j.../specificationsProductType=mk_connection_unit in B&Q earlier but not sure if this is the right one with it being 13A and looking slightly different. Is there another MK one at B&Q that I should be using? Thanks

 

[PrenticeBoyofDerry]

So the isolator for the bathroom fan is a S/FCU (switched fused connection unit) then?
What you need to do is remove the fuse in your existing/broken isolator, that is providing it is S/FCU?
Then remove the 13A fuse from the MK S/FCU that is located at B&Q and put the fuse from the existing one in to the new one.
As the rating of the fuses should be different.
Then note down the wiring in the existing S/FCU and do the same in new one.
If you think there is an issue and they may not be of the same type, take a picture and upload and post so we can have look to confirm!

 

[andyj941]

Hi thanks for the quick reply! There is no fuse in the existing switch

 

[PrenticeBoyofDerry]

as edit

If you think there is an issue and they may not be of the same type, take a picture and upload and post so we can have look to confirm!

A picture of the inside terminals would also be nice.
Could be a standard switch or a an isolating switch (20 Amp DP Switch)
If you can't take a picture/upload one.
Please explain the terminals inside the switch/isolator.

 

[andyj941]

Untitled

• andyj941
• 7 Oct 2011
• 1

Untitled

• andyj941
• 7 Oct 2011
• 1

 

[PrenticeBoyofDerry]

You want one of these then
http://www.tlc-direct.co.uk/Products/BG930.html

 

[andyj941]

OK I wonder if MK do one that would do the same thing?

 

[PrenticeBoyofDerry]

They will do, you could still use the S/FCU just needs a fuse in it that is rated at at least what the fan output requires and no more than the rating of the circuit that the switch is on.

http://www.qvsdirect.com/MK-Logic-Plus-20A-Switch-with-Flex-Outlet-White-pr-16304.html

at B&Q

 

[andyj941]

OK I don't know what the rating of the circuit is but it's on the upstairs light circuit if that's of any help. Likewise with the fan, no idea what the fan output requires!

 

[PrenticeBoyofDerry]

They are usually quite a low output and normally connected to the lighting circuit. There should be no problem with using either the 20A switch or the Switched FCU just make sure the fuse in the FCU is either the same as the lighting circuit or a little lower. 5A or 3A fuses should be fine.

 

[diynoob]

Do the regs state that the extractor fan switch has to be labelled as such, rather than one of those that just look like a light switch? Thought I read that in a previous post, could be wrong though.

 

[diynoob]

This is what I was thinking of, it's a bit vague though:

462-01-02 Each device for switching off for mechanical maintenance shall be suitably located, and identified by durable marking where necessary.

It could be interpretted to mean that fan isolator switches should be the labelled ones like this www.qvsdirect.com/Slimline-White-3-Pole-Fan-Isolator-Switch-pr-24506.html