Extractor Fan Again

[peterduckett]

Hello

I'm trying to wire a new extractor fan which requires a L, SW, N,
According to the instructions this needs to have an isolator and a fuse so I'm trying to figure out the wiring.

My idea is to take T&E of the lighting circuit to a DP fused sure then take more T&E to a switch from the switch I would like to take 3 core and earth from this switch to the fan with the perm live took from the input of the live.

Does this sound reasonable that way both lives are fused and isolated though the spur but the switch is used to connect the extra switch live.

I did look though the Wiki but it seems that most people would use a DP switch to activate the fan and light together

 

[Aragorn84]

I've not looked at the wiki, but i'd imagine the normal method would be to take a live and neutral from the lighting loop to provide the permenant supply to the fan, and a feed from the output side of the light switch to the switched live, all running thru a 3 pole fan isolator.

You really only should need a single 3 core and earth cable going to the fan/isolator.

 

[Spark123]

Your method seems fine with one slight drawback, you'll need to isolate the light to clean the fan.
Another method is to use an unswitched fuse spur unit instead of a double poled switched fuse spur to feed the fan + light, and install a 3 pole isolator in the 3C&E to the fan so it isolates the fan only.

 

[ban-all-sheds]

Your method seems fine with one slight drawback, you'll need to isolate the light to clean the fan.

Err..

No....

My idea is to take T&E of the lighting circuit to a DP fused (spur) then take more T&E to a switch

 

[Spark123]

I took that to mean he was putting a chock block in the back of the switch for the neutrals.

 

[ban-all-sheds]

Together with

from the switch I would like to take 3 core and earth from this switch to the fan with the perm live took from the input of the live.

I took it to mean he was taking L&N from the lighting circuit to a DP switched FCU (presumably to meet the maker's requirements for fusing), then to a switch, and then L/SL/N to the fan.

Therefore the DP switched FCU would completely isolate the fan.....

 

[Spark123]

Yep, but like I said it would kill the light too.

 

[ban-all-sheds]

My idea is to take T&E of the lighting circuit to a DP fused sure then take more T&E to a switch...

Not the existing lighting switch..

 

[peterduckett]

So it looks like i have it correct in my mind to meet the extractor fan spec