Vent Axia ACM100T

[oldguy]

Hello,

About to order this fan, but the wiring diagram shows a 2 pole fan isolator.

Can I use a 3 pole as per the alternative wiring diagram?

From lighting circuit, take L&N through a 3 amp FCU to the isolator....

I will put a new pull cord in as I want to switch separately from the lights

thanks

VA Timer

• oldguy
• 8 Jun 2016

Shower_fan_wiring-HARMONISED

• oldguy
• 8 Jun 2016

 

[stem]

There are two different installation methods shown.

Method 1 is where the fan is connected to a 'power' circuit (e.g. 32A) so a 2 pole isolator incorporating a 3A fuse is shown. The same concept can be used if the fan is connected to a lighting circuit and has it's own dedicated switch to control it, so you can use a 2 pole isolator. The disadvantage here is that when the pull cord is operated, the fan will continue to run for a time, so you may forget if you have switched it off or not.

Method 2 is where the fan is connected directly to a 'lighting' circuit (e.g. 6A) and does not have an additional fuse. Here the fan is controlled in conjunction with the light switch.

Both methods are correct, the important thing is that when the isolator is operated, all of the live(s) and neutral are isolated from the mains supply. If the fan is in a bathroom the location of the isolator should be in the correct zone, and that it has RCD protection. Many lighting circuits don't.

 

[oldguy]

thanks, well I'll go method 2 since the fans obviously in the loft space and means I can easily connect to the lighting circuit.

As the fan is in the loft I had intended to put the isolator up there too, in the 'outside' zone, or does the isolator have to be 'easily' accessible - most modern houses have them on the outside of the bathroom at high level which I don't like, would rather site it near the fan......

 

[stem]

The usual method of installation is as you describe, however, it could be possible for someone to turn the isolator 'on' outside the bathroom, whilst someone was in the loft working on the fan, so you could argue that putting the isolator in the loft near the fan would actually be a better idea. On the other hand if the fan developed a fault, or its internal switching circuit failed so that it ran permanently, you would have to go up into the loft to isolate it. You might get more comments on this....

 

[Iggifer]

It reads like the OP could mean he wants it in the bathroom as he mentions the 'outside zone'

I've seen plenty of them on ceilings inside bathrooms where it's been added after the fact - much easier than chopping out the wall to put it by the door

 

[Taylortwocities]

The isolation switch is for your convenience, so that you can isolate the fan for "maintenance" while the bathroom light remains energised. (Everybody "maintains" their fans in the night-time!).
It is a requirment if the bathroom does not have a window (= no natural light).

So it is your choice where you site the isolation switch.

 

[EFLImpudence]

It is a requirment if the bathroom does not have a window (= no natural light).

I would disagree with it being a requirement and especially for that reason.