Humidistat Extractor Fans In Kitchen and Utility Rooms - Isolator Needed?

[leevis]

Hi
I'm putting in a couple of extractor fans, one in my Kitchen and one in my Utility Room and need to understand if Isolator switches are required.

These are both Humidistat ones so they go on and off on their own, both of these are close to natural light (both from above velux window and from a window) so lighting is not an issue regarding working on them. They will also be on their own circuit on the consumer unit.

Question is, do I need to put one in? don't want it if its not needed and those big switches look a bit grim

 

[leevis]

Just thinking about this, I have a grid switch which I can add the extractors to, would this be sufficient? The one in the kitchen I could connect to that so it would be isolated there. It would be great if it was allowed to isolate both from the same switch but if this is not allowed I could put a normal isolator in the utility room as its not as 'seeable' in there

 

[Taylortwocities]

Do your fans also operate when the light comes on? Or is it only humidity?

If it is humidity only you’ll only need a two pole isolator (live and neutral) so you could use a DP switch in your grid plate. If the fans are also triggered by the operation of the light then you’ll need one of the larger 3-pole fan isolator switches.

You don’t actually have to install an isolator for the fan. They are handy for maintenance, but you could turn off the MCB for that circuit when you need to clean or replace the fan, every 10 years or so.

 

[leevis]

Humidity only. What I think I will do is just get a two pole for the grid (luckily there is space for one) in the kitchen and then get a double pole one for the utility. No space on that grid so will get a new face plate etc which will fit all.
Thanks very much

 

[Taylortwocities]

Dont forget that you may need to fuse the fan appropriately. That may be another space in your grid, unless you are running the fan from a lighting circuit?

 

[plugwash]

I would argue that regulations aside, it's a very good idea to have a means of disconnecting any fixed load.

The special 3 pole "fan isolator" switches are only needed for timer run on fans associated with a light, where there are two different live conductors to disconnect.

If you are feeding these fans off a socket circuit you will also need appropriate over current protection. Generally that means either a FCU or a fuse module in a grid.

 

[leevis]

its being run on a lighting circuit

 

[Taylortwocities]

its being run on a lighting circuit