Extraction fan (2 gang light switch)

gazdkw82 · Jul 9, 2018

I've never done anything with extraction fans but I've got a job coming up where the customer wants to remove pull cord for extractor fan and pull cord for light and put into a 2 gang wall mounted light switch.

The light switch would be 1.2m away from the edge of the bath. The extractor fan is a cieling mounted fan and they plan to keep this. The fan is above a walk in shower.

I don't know yet if the fan is mains or 24v.

Many questions on this job as I've not seen it yet but my first question is, is it acceptable for an extractor to switched via a light switch? Is there a reg that states a fan isolator switch is needed? If so can the fan be switch via a wall mounted switch and also a local fan isolator?

Richard Burns · Jul 9, 2018

Yes an extractor fan can be switched with a light switch either independently or with the lights.
For a timer fan it is recommended that there is a triple pole isolator, double pole if not timer, manufacturers usually state that the supply should be connected through a double pole isolation switch, just to add to the fun.
A triple pole plate switch could be installed higher up on the wall above the two gang switch if it is required. A double pole switch could replace one gang of the light switch (if it is a grid or Click Scolmore )
Rooms with no openable window should have a timer fan with 15 min overrun (you really want a quiet fan then).
If the fan is 230V then it must be IPX4 minimum.

gazdkw82 · Jul 9, 2018

Thanks for the response.

I will use a 2 gang 2 way light switch with a separate fan isolator just below ceiling level.

I will also check the fan voltage and check the ip rating.

Thanks

gazdkw82 · Jul 11, 2018

Been and assessed the situation.

The install is pretty simple. 6 new downlights (ip65) around bathroom (2 above walk in shower), a 2 gang switch for lights and extractor. Extractor isolator to be fitted also. Extractor is 230v, ipx4 and will be above walk in shower.

The only issue I have found is none of the installation is RCD protected. I explained to the customer RCD protection will be needed which they understood and agreed. However in this situation is there an expectation to provide RCD protection for the entire installation or just the circuits I will be doing the remedial work on?

If just the circuit, what is the best way to provide RCD protection on a rewireable board? Separate enclosure with RCD?

Thanks

Richard Burns · Jul 11, 2018

The ideal situation is to change the entire board and bring everything up to current standards, however on a practical and regulatory basis it is only the work that you do that needs to be up to standard.
The circuits that you work on in the bathroom must have 30mA RCD protection, whether this is an RCD FCU at the start of the bathroom lighting protecting just the bathroom lighting and the extractor fan or whether you can apply an RCBO to the whole lighting circuit or perhaps a stand alone 30mA RCD near the consumer unit and diverting the lighting circuit through that, is up to the customer and you to assess the simplest and best method of compliance.