Wiring Bathroom Light and Fan from the switch

[Electric Magic]

Just completed a flat rewire. The bathroom had no windows or external walls so needed a ceiling extraction fan with a timer (when I got there the builder had already attached ducting for it to an existing asbestos pipe!!). I usually wire lighting using the loop method, and did so on this occasion, but it can be a pain in the a**e on bathroom lights where there is also a fan, particularly when the one the customer has selected only allows you to bring in one t&e cable.

So instead of:

1. Taking the cable to an FCU (fan chosen required 3 amp fuse)
2. Going from the FCU to MF junction box above light
3. Cable from junction box to the switch (line to and switched line back to junction box)
4. Cable from junction box to light
5. 3 core and earth from junction box to fan isolator (line, switched line, neutral)
6. 3 core and earth from fan isolator to fan

I was thinking of:

1. Taking the cable to an FCU (if fan chosen requires 3 amp fuse)
2. T&E from FCU to light switch
3. T&E from light switch to light
4. 3 core and earth from light switch to fan isolator (line from supply side of light switch, switched line and neutral)
5. 3 core and earth from fan isolator to fan

Can anyone see any issues with this method?

On this last job it would have saved me a significant amount of cable and time on a ladder with my arms above my head (it was top floor in a flat roof maisonette so couldn't do any work on it from above).

 

[telectrix]

as long as it works and complies with BS7671, then it's fine.

 

[amlu]

for me all connections to be done in the switch box... use wago connectors for tidy results.
one cable to terminate in the light and no junction boxes needed.

 

[SJD]

Rather than a separate FCU and fan isolator, I use a combined one - click minigrid - the 3 pole isolator is 2 modules wide, the fuse is one module wide - fits into a standard single gang faceplate & box.

 

[Electric Magic]

If you use a Hager switch you only need a Wago connector for the cpcs as they have a neutral terminal. Used Hager wiring accessories for the first time on this job and I was impressed, particularly with the sockets. They look good, the terminals are in a sensible place for inspection with plenty of space,and the screws are reasonable quality.

 

[Electric Magic]

Thanks for the tip I'll have a look at it.

 

[Electric Magic]

How do you wire that SJD? Presuming you would want to fuse the switched line as well as the line...

 

[Richard Burns]

How do you wire that SJD? Presuming you would want to fuse the switched line as well as the line...

presumably like this or something similar:

 

[R G]

for me all connections to be done in the switch box... use wago connectors for tidy results.
one cable to terminate in the light and no junction boxes needed.

Best way, with all the various types of light fittings around mostly have no room for all the cables, also prevents the use of hidden joint boxes in voids too..