Installing New Wall-Mounted Fan on Main Ring

[samstu]

I want to install a wall-mounted fan (with timer overrun) in my house and want it to be switched independently from any lighting.
I would like to make the installation by using a DP SFCU and separate 1 way single pole switch and have made a sketch of how I think this would work.

Untitled

• samstu
• 30 Mar 2011
• 3

I plan to take a spur from the main ring (which originates at a 30A MCB which, in-turn is RCD protected at the CSU); the initial spur cable will be 2.5mm T&E as per the main ring and this will terminate at the DP SFCU which will be fused at 3Amps. Between the SFCU and the single pole switch, I will be using 1.5mm T&E; because the fan has an overrun timer, it requires a permanent and a switched live so I plan to use 1.5mm 3 core and earth between the SP switch and the fan.

The permanent live and switched live will be obtained at the SP switch, the neutral for the fan will be achieved by connecting the incoming neutral (blue) to the outgoing grey (sheathed blue), this connection will be via a terminal block in the SP switch pattress.

Will this work?
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[holmslaw]

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[ericmark]

Yes it will work. The idea of taking a 3A fused supply to a double pole switch so one pole works the fan and the other the light has been shown on here a lot to get around the manufactures requirement for a 3A fuse in the supply.

Oddly using a pneumatic timer switch rather than connecting to lights often follows the Part F requirements better than using the light switch.

The problem is where there is a non opening window there is no need to switch on the light so the user may be unaware of how to activate the fan without also wasting energy by switching on the light.

However using a timer either built into switch or built into a PIR means there is no real need to have a timer built into fan.

Although you can fit a fan in the loo do remember in a bathroom or kitchen Part P raises its head and likely better not to DIY.

 

[samstu]

Thank you for the speedy replies

Sorry, the diagram should have shown a single pole switch not the lighting type switch that I included.

The purpose of the SP switch is simply to take the feed from the SFCU and allow the fan to operate, there will be no connection to or from a lighting point or circuit.

Does this affect whether the proposed layout will work or not?

Thanks again

 

[EFLImpudence]

Just a suggestion - it may not be what you want - I don't know how high your wall is.

If you obtained a fan with an integral pull cord switch then you wouldn't need the second wall switch or three core cable.