Extractor Fan

[bhm1712]

I have had an electrician round today (im only 17th not part P and find it much easier to pay somebody rather than notify) to see about putting in a supply for an extractor fan in the garage. Basically its going to be a bathroom extractor type fan.

Now in my bathroom, the fan is fed from the lamp celing rose via a three pole pull cord. This fan comes on when the pull cord is switched on and when the pull cord is switched off it runs on for about 10 mins. However the fan doesnt take a switched live from the light switch. As its currently wired, the Live and Neutral go from the ceiling rose to the incoming side of the pull cord L1 and N. L2 is vacant on the incoming side, however a link from L1 incoming goes to L2 outgoing. This has been used to give a permanent live to the fan, with L1 being the switched live. (No isolator on this fan as i believe it was installed around 1993)

The spark who came (never used him before but my old sparky is dead...) says if i want the new fan to work as the current bathroom one does (with a three pole isolator of course....) and have it turned on by a switch ,but running on for n mins automatically i can only achieve this by using the switched live from the garage light switch and use the light switch as the run signal, and the permanent live for time delay shutdown will come from the ceiling rose. However i dont want to run the fan from the light switch as i wont be using the lights when the fan is on. The lacquering im going to be doing regularly will be done in the daytime and the garage has windows..... Is there no way that a pull cord could be used to provide a switched live and neutral from the ceiling rose, and a permanent live could be provided from a JB above the pull cord?


What would you suggest?

 

[EFLImpudence]

I think I have read correctly.

You can get the L,N,E supply from wherever you want.

Once you have installed the switch (pull cord) you will then have a permanent live and a switched live.


supply > 2c+e > 2P iso > 2c+e > pull cord > 3c+e > fan

 

[ericmark]

When used in a bathroom or toilet with daylight and non opening window i.e. required by building regulations the lights can't be the only method of turning on the fan it must also have another means normal is a pneumatic push switch.

Because of this common to use a double pole light switch so although switched on with lights it is a physical not electrical connection.

Any proper domestic electrician should be use to doing this so it would be the same as far as your system is concerned be it duel switching or single no real reason to use lights.

Using a PIR is also common but the whole point is that it forces fan use and really for what you are relating no need to force use you will select when it is required.

In fact no real need for run on either.

The isolator is used because fans do fail and when they do it needs to be switched off so lights still work. However if the switching is manual then no need for isolator.