Understairs Cloakroom Wiring

[wingit]

I'm installing a new under stair toilet. Previously from a junction box in the vicinity,
a light with switch was wired up, I've just used the same cable from that box.
The junction box is shown on the left of the picture below.

I've added a second small junction box to run an extractor fan and a new mains LED ceiling light from.
The fan is not timed, just works on a pull cord. The light will have a pull cord for operation as well.

As the fan and LED light only need live and neutral I'll use terminal blocks to terminate the earth cables.

I've read quite a few threads on the forum, but can't convince myself that I've wired it all up correctly,
so advice would be greatly appreciated. Cheers.

Untitled

• wingit
• 11 Mar 2013
• 1

 

[ban-all-sheds]

Previously from a junction box in the vicinity,
a light with switch was wired up, I've just used the same cable from that box.

If that was a switch drop cable it won't work, as there won't be a neutral present.

The fan is not timed, just works on a pull cord.

I doubt that Building Control will accept that - they'll want one with a timed overrun which is triggered by the light.

Also, although the electrical work per se is non-notifiable, as it's part of work which is, be aware that they might want proof that it complies with Part P.

As the fan and LED light only need live and neutral I'll use terminal blocks to terminate the earth cables.

You can't use a choc-box as shown, as it won't fit into the light switch, and therefore you'll end up with exposed single-insulated wires.

I've read quite a few threads on the forum, but can't convince myself that I've wired it all up correctly

You haven't.

 

[wingit]

The fan is not timed, just works on a pull cord.

I doubt that Building Control will accept that - they'll want one with a timed overrun which is triggered by the light.

Also, although the electrical work per se is non-notifiable, as it's part of work which is, be aware that they might want proof that it complies with Part P.

I have just checked with the building regs people, and you are indeed correct.

 

[wingit]

As the fan and LED light only need live and neutral I'll use terminal blocks to terminate the earth cables.

You can't use a choc-box as shown, as it won't fit into the light switch, and therefore you'll end up with exposed single-insulated wires.

I see, so a section of connector strip inside the switch?

as seen here //www.diynot.com/wiki/electrics:other:chock

 

[wingit]

Previously from a junction box in the vicinity,
a light with switch was wired up, I've just used the same cable from that box.

If that was a switch drop cable it won't work, as there won't be a neutral present.

I have to say I'm not much wiser for that post.

 

[wingit]

I've read quite a few threads on the forum, but can't convince myself that I've wired it all up correctly

You haven't.

'tis abundantly clear now

 

[ban-all-sheds]

I have to say I'm not much wiser for that post.

Previously from a junction box in the vicinity,
a light with switch was wired up, I've just used the same cable from that box.

If the cable you use is the one which used to go to the switch then your new stuff won't work because the switch cable won't have a neutral in it.

//www.diynot.com/wiki/electrics:lighting

 

[wingit]

I have to say I'm not much wiser for that post.

Previously from a junction box in the vicinity,
a light with switch was wired up, I've just used the same cable from that box.

If the cable you use is the one which used to go to the switch then your new stuff won't work because the switch cable won't have a neutral in it.

//www.diynot.com/wiki/electrics:lighting[/QUOTE]

I think I understand now:
The existing light is still wired in place, I've taking a photo of how it's wired up.
Grey cable coming from junction box, white cable to a small door activated stitch.

Untitled

• wingit
• 12 Mar 2013
• 1

Does this have a neutral?

 

[ban-all-sheds]

OK - looks like it does, but either the neutral is switched or the wrong colours are being used from the JB.

It also has no earth continuity - you MUST rewire it so that it has.

 

[wingit]

OK - looks like it does, but either the neutral is switched or the wrong colours are being used from the JB.

It also has no earth continuity - you MUST rewire it so that it has.

I will ensure earth continuity.

Is it easy to visually check that the neutral is switched?
or do I need to get my multimeter out and remind myself how to use it?

 

[securespark]

Not seen a fitting like that before: what does the rest look like OOI?

EDIT: If that terminal in the photo with the blue conductor attached is the return from the switch, then (with power off) put your multimeter (set to continuity) across it and the cpc in the grey cable. If the blue wire is neutral, you should get some indication of continuity.

You need the cpc connecting to earth at the other end, if it is not already.

 

[wingit]

Not seen a fitting like that before: what does the rest look like OOI?

EDIT: If that terminal in the photo with the blue conductor attached is the return from the switch, then (with power off) put your multimeter (set to continuity) across it and the cpc in the grey cable. If the blue wire is neutral, you should get some indication of continuity.

You need the cpc connecting to earth at the other end, if it is not already.

OK, got it thanks.

here's the front of it

Untitled

• wingit
• 12 Mar 2013
• 1

 

[securespark]

Seen plenty of old fittings but not one like that before. Thanks for posting the pic.

There is a live test for the neutral check, too. It requires confidence and no children around...

With power on & the MM set to the AC range including 230V, put the meter across the terminal with the blue wire and the cpc in the grey cable. If the blue is connected to neutral you should get 0V.

With both tests, the door has to be open (the switch contacts closed).

 

[wingit]

Not seen a fitting like that before: what does the rest look like OOI?

EDIT: If that terminal in the photo with the blue conductor attached is the return from the switch, then (with power off) put your multimeter (set to continuity) across it and the cpc in the grey cable. If the blue wire is neutral, you should get some indication of continuity.

You need the cpc connecting to earth at the other end, if it is not already.

I turned off the power at the consumer unit.

Opened up the junction box, the earth wire in the grey cable seems to connected to earth in the JB.

I put the multimeter in continuity mode, and located one probe on the blue cable junction,
I located the other probe on the earth cable seen poking out of the grey cable in the first pic. Result, no continuity.

Not sure I'm doing this right

Almost at the point of calling in a professional.

 

[wingit]

Seen plenty of old fittings but not one like that before. Thanks for posting the pic.

There is a live test for the neutral check, too. It requires confidence and no children around...

With power on & the MM set to the AC range including 230V, put the meter across the terminal with the blue wire and the cpc in the grey cable. If the blue is connected to neutral you should get 0V.

With both tests, the door has to be open (the switch contacts closed).

Gulp, bottle gone.

I'll post you the fitting when I'm done if you're a collector of such oddities.