Extractor fan install - basic type no timer

[wilburwilbur]

I would like to fit an extractor fan in the loft space above my shower room with ducting to the outside. I want it to come on when the light is switched on. The type i have is without a timer overrun. The instructions say to put a double pole switched connection unit in the circuit before the pullcord switch & the switch is shown as a single pole type. I would like to know at what point to connect the light. I have also been reading about the 3 pole isolation - this is not mentioned in the instructions for a basic extractor.

extractor basic type install instructions

• wilburwilbur
• 4 Apr 2013
• 1

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[OwainDIYer]

Does the manufacturer actually specify a 3A fuse is required, or is that simply an example?

If a 3A fuse is required, then from the switched live and neutral at the light, run t&E to the fused DP connection unit, then t&e to the fan.

The light switch will then control both.

 

[wilburwilbur]

yes this image is from the instructions provided.

 

[sparkzzz]

best thing to do is wire a length of 1mm2 twin and earth from the switch wire of the light obviously connecting the neutral and the earth, take that into a switch fused spur and then come out of the switch fused spur to the fan, make sure you put a 3A fuse in the spur, your lights should be fused at 6A anyway so any fuse above 6A in theory should be irrelavant. Ive seen 6A MCB'S running at 15A without a care in the world so for your own sake put a 3A in there. Hope this helps

 

[securespark]

Why don't you want an overrun?

And why don't you want the ability to switch the light on without the fan?

You could achieve both these things with a timer fan and a TP isolation switch.