Timer fan wiring

[Rich_W]

All,

I've followed the wiring diagram below and wanted to check something with you:

When I switch on the light, the neon indicator on my double pole switch comes on (it's wall mounted, outside the bathroom). This is with my SFCU to the fan switched OFF.

If I turn the SFCU to the fan ON, the neon light goes OUT.

It seems to me as if I've got something wired in the wrong way around, as I would expect the neon light to stay off when the SFCU is off.

For clarity, I have assumed in the diagram the the top section of the DP light switch is the feed and that the bottom section is the load.

The switched live from my bathroom light is in the feed live connection on the switch, the feed neutral has the permanent live going to the JB (and eventually to the fan). The live from the bathroom light is wired into the live load connection and the switched live to the JB is in the neutral load.

It seems to work at the moment, but I get the feeling that the effect is that my the SFCU to the fan is wired the wrong way round - i.e. when the SFCU is OFF, the fan will come ON.

Can anyone offer any suggestions?

Thanks,
Rich

 

[plugwash]

lemme guess you used a shower pull cord that wasn't really what i had in mind when i did the diagram

right now the neon is connected between the two sides of the switch which is NOT what you wan't in that setup. you need to disconnect it from the fan side of the switch and then replace the cable to the lightswitch with 3&E so you have a core to bring a neutral to the neon.

 

[Rich_W]

lemme guess you used a shower pull cord that wasn't really what i had in mind when i did the diagram

I'm not using a shower DP pull cord - the light switch is wall mounted.

From your reply, I think I understand that the wiring in the fan side side of the switch should be replaced with 3&E. However, I'm not clear on how that reconciles with the diagram (and therefore what should be wired where) - the diagram doesn't show 3&E to the fan side of the light switch.

Happy and willing to take advice - I'm just not sure how to interpret the advice being offered at the moment.

Thanks,
Rich

 

[fireman22]

isnt this dangerous to next person working on system? they will switch off spur unit to change pull switch for example, and there will still be a live connection in it

 

[plugwash]

ok modified version of the diagram for a switch with neon

you will likely have to cut one of the wires to the neon and join it with terminal block to achive this. when cutting it make sure you cut it off in such a way as not to leave it in danger of shorting anything (i'd probablly try and get the cutters partway inside the hole it comes out of)

 

[Rich_W]

Many thanks Plugwash - that makes sense now. Thanks for taking the time to modify your diagram.

Equally, could I swap the current DP switch with neon for one without, and retain my existing wiring configuration? I'm not concerned whether I have neon or not - it was simply the only DP switch I could find at the time.

I saw the link to TLC for the pull cord switch, but I'd like a wall mounted one. Does anyone know where I can source one of these?

 

[plugwash]

pretty much any electrical supplier.

http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=75755&id=13264
http://www.tlc-direct.co.uk/Products/BG930.html
http://www.electricalshop.net/acatalog/20_Amp__Upto_4600_Watts_.html

 

[Rich_W]

Perfect - thanks again.