LED switch on extractor fan

[theretrophoenix]

I'm hoping someone can help me with this wiring.

I have fitted an extractor fan that has humidity & override. I've created a spur from a ring main with 2.5 T&E cabling, to a fused spur with 3a fuse (crabtree 4827). I was told I must do this as I've tapped off the ring main. From the spur I've used 3&E cabling. The 3&E then feeds from the sur to the fan kill switch (crabtree cr1008), then into a switch for the switched live, so that I can switch the fan on or off (crabtree cr1014) when I want. The permanent live & neutral cables bypass this switch with the aid of two wago connectors. The 3&E then feeds into the fan.

Everything works fine & dandy, the fan comes on when it detects too much humidity & runs for about 15 minutes & I can turn it on & off when I need it with the switch (crabtree cr1014).

There is however one issue. The on/off switch (cr1014) has an intergrated LED as I wanted a visual reminder that I'd actually switched it on & then know that I need to switch it off. So the switch works as an on/off switch to power the fan OK, but the integrated LED (in the switch) doesn't come on as the neutral cable bypasses the switch as it is needed for use with the permanent live.

Not wanting to mess with the wiring & do anything dangerous I've left it in this position, but I'd really like the LED to come on when I turn that switch on.

So can I create & add a loop from the existing neutral cable at the wago connector to go through the neutral terminals in the switch? To me this seems logical as the existing neutral will work with the permanent live & also the switched live, in so far as when the switch is in the off position, the flow will go through the cable in its current configuration, but with the switch on, it will also go through the switch, thereby powering up that LED.

Or do I need to do something completely different? Obviously I'm not an electrician, so if anyone has a solution that works, please let me know.

 

[Adam_151]

I'm not actually sure what you are asking, you are correct that you need to take a neutral to the supply neutral of the switch for the neon to work, which you seem to release, but I'm not sure where the rest of the question is going

Have you got some pictures of what you have done?

 

[securespark]

I guess you are wiring this fan independently of the room's light?

If so, you need this diagram:
The only thing you would do differently is to attach the neutral to one side of the LED indicator.

There is no need for 3 pole (not 3 way) isolation switch if using the above method, because switching off the fused connection unit will isolate everything on the load side of the FCU.

Why not use the FCU for isolation? That can have an LED indicator if you so wish.

 

[ericmark]

There is a limit to what can be included the fused fan isolator it may be possible to get a grid switch to do it all, but likely will need a double back box.

three pole grid switch Fuse holder red indicator but that will not fit in a single back box.

 

[Sureitsoff?]

sounds like you just need to use the neutral side of the switch to join the neutrals rather than a wago

as the switch is a double pole 20A (chosen for the led I assume)

 

[theretrophoenix]

Responding to sureitsoff. If I do that, yes the LED will work, but then the fan will only operate as an on/off fan in that position. From my understanding of electrics (which I know is basic) we have live & neutral which I think of as flow & return. So by moving the neutral cable so it is operated by the switch, the fan will not operate as intended as the humidistat & timer will only have a permanent live. Not a neutral, so it would not have that return flow. It would only flow when the switch is in the on position.

It is operating as it's designed to at the moment because it's wired up correctly. If I'd have fitted a regular on/off switch it would be working 100%. It's only the fact that I wanted to use a switch with an LED which puts a spanner in the works. In my mind (appologies as I'm on the autistic spectrum) the electrics need flow & return. These are perm live & perm neutral which allow power for the humidistat/timer. There is also another live (switch live) that operates the on/off function of the fan. This works as when on, it uses the perm neutral. However, the integrated LED on that on/off switch does not work with this configuration as there is no neutral connected to that switch.

I'll make a diagram & take some photo's later so everyone can see. But in the interim, it's all working except for that LED in the on/off switch because the required neutral cable is being used with the perm live cable to power the humidistat. That neutral is shared for both live & switched live.

 

[EFLImpudence]

 

[ericmark]

An isolator should switch all live wires, a switch only needs to switch the line wires the neutral does not need switching (neutral is considered a live wire) so with the triggure wire it needs three sets of contacts, I have shown a three pole switch with neutral and fuse, but to get the indicator as well you will need a larger back box.

 

[ericmark]

View attachment 316880

I would say that is dangerous as with switch off the fan is still live.

 

[EFLImpudence]

Isn't that why it is called Permanent Live?

 

[EFLImpudence]

How else does the humidistat work?

 

[theretrophoenix]

OK guys. Thank you to all who've contributed so far, but perhaps I should've called this thread 'how to get the LED working'. The fan is wired 100% correct, it operates 100% correctly, but it's just getting the LED in the switch to work which is the problem.

I've taken some pics & drawn a little schematic showing exactly how it is wired.

Any help that finds a solution to getting the LED to work would be appreciated.

 

[Sureitsoff?]

are you using the led switch to switch the fan on and off or letting the humidistat do it?

dont switch the neutral in the switch simply use whichever of the neutral terminals the led is connected to as a junction. the switching of the live will bring on/off the led then

 

[EFLImpudence]

...

 

[EFLImpudence]