Confusing bathroom lights and fan wiring

[stringsonfire]

As a matter of interest does the fan carry on for a while after the switch is turned off, the wiring from what I can make out suggests it does not.

You're right, it doesn't stay on, turns off straight away.

if you post your location 1 of us may be close to sort it for you.

Welwyn Garden City, Hertfordshire

It isn't that unconventional! It is just a method of wiring using an sfcu to give isolation to all 3 live fan conductors whilst not isolating the bathroom light (so that you can see what you are doing!). Avoids having a triple pole isolator and is a neat way od doing things

Good to know it's possible. Any idea how?

 

[westward10]

Looks like double-pole switch to me using the neutral terminal for the lines and which does not isolate all poles if you include the neutral so yes I would say it is unconventional.

 

[westward10]

If it turns it straight off I would suggest it was or is now incorrectly connected assuming the three core cable runs to the fan and the fan has a run over function. From here we can only recommend getting an electrician involved I am afraid but it can be done.

 

[mhar]

You have a perm live to one supply pole of the dp light switch which is also taken to the in of the sfcu, the load pole is connected to the lamp. The fused out of the sfcu returns to the other supply side of the dp switch plus goes directly to the fan.The fused out of the dp switch goes to the fan as switched live. The supply n of the sfcu is also connected to the lamp, the out goes to the fan thus giving 3A fusing on both fan line conductors and all 3 fan live conductors can be isolated via the sfcu without affecting the operation of the light

 

[telectrix]

You have a perm live to one supply pole of the dp light switch which is also taken to the in of the sfcu, the load pole is connected to the lamp. The fused out of the sfcu returns to the other supply side of the dp switch plus goes directly to the fan.The fused out of the dp switch goes to the fan as switched live. The supply n of the sfcu is also connected to the lamp, the out goes to the fan thus giving 3A fusing on both fan line conductors and all 3 fan live conductors can be isolated via the sfcu without affecting the operation of the light

but when did OP mention a SFCU?

 

[westward10]

Is it just me but from that switch I cannot work out how the fan works. Due to the amount of neutrals that is not end of line and the neutral terminal with three browns, it looks like two but is three is the loop terminal so I suspect there is a shaver socket. The other brown on its own goes to the lights, the triple core conductors assuming that is the fan are isolated at the switch from the loop in lines?

 

[stringsonfire]

Is it just me but from that switch I cannot work out how the fan works. Due to the amount of neutrals that is not end of line and the neutral with three browns, it looks like two but is three is the loop terminal so I suspect there is a shaver socket. The other brown on its own goes to the lights, the triple core conductors assuming that is the fan are isolated at the switch from the loop in lines?

Just checked, the shaver socket power disappears when I turn off the light circuit breakers

 

[westward10]

Yeah I am singing out load here because the more I look at it the more it intrigues me. If those connections are original and your electrician hasn't changed them and this won't help you but may be of interest to another electrician you need to employ. Those two wires to the left which are part of the three core cable do nothing and the fan is connected direct from the lights or, there is a secondary live to the switch which does use those two wires to switch the fan. My conclusion is someone has incorrectly connected the fan.

 

[littlespark]

What have you got there? 4 twin&earths and a 3core and earth?
Instinct says the 3 core should got to the fan isolator, then onto the fan.... but where they are connected in the switch suggests otherwise.

There are too many cables there for anyone to give an educated guess without knowing what cables are at the kitchen switch or the isolator.

 

[westward10]

I believe you have live in, live out, output to the lights and a shaver socket output. The triple-core is totally confusing by the manner in which it is connected.