Bathroom fan

[andydiynot]

Hi, I fitted down lights in my bathroom replacing old rose & decided to add a Fan (Vents 100 mtpk) it is pir with timer . My query is it only has two pole connections not marked L or N. I have assumed that because it has over run timer it must have a live & a switched live. It works ok ie(pir )until the light is switched on which switches the fan off,have changed live & switched live in fan around but made no difference.Any help please

 

[sparkyspike]

Could you clarify the name and model number?

It sounds like you only need a permanent live and neutral. The PIR does the switching and the run-on is automatic. So wire a permanent live and neutral into the two terminals. Not a live and switched live (which is why it stops with the light on).

Please clarify the model first though.

 

[rebuke]

If it's only got two terminals, then that would imply it expects a permanent live. I somehow doubt they're not marked L/N however - what does the manual for the fan say?

I'm confused as to how you could have it wired such that switching the light on turns the fan off - unless you've somehow wired up your light switch in a two way mode, so what you think is a permanent / switched live is actually an inverse switched live. Pictures of behind the switch, and any junction boxes used would help us figure out what's going on...

Also, as this is in a bathroom all of this work is notifiable under Part P of the building regs (see the wiki for details) so I assume you've already notified the LABC?

 

[sparkwright]

is it that the fan isn't supposed to work in conjunction with the light, relying on just perm live and neutral.

we could do with model number.

 

[andydiynot]

Could you clarify the name and model number?

It sounds like you only need a permanent live and neutral. The PIR does the switching and the run-on is automatic. So wire a permanent live and neutral into the two terminals. Not a live and switched live (which is why it stops with the light on).

Please clarify the model first though.

Hi thanks for the quick response,I forgot to mention that there was a fan there before which was marked as Live ,switched live & Neutral.This new fan is a Vents 100 M axial fan. type vents 100 MTPK.
I will wire as live & neutral.Thanks

 

[andydiynot]

If it's only got two terminals, then that would imply it expects a permanent live. I somehow doubt they're not marked L/N however - what does the manual for the fan say?

I'm confused as to how you could have it wired such that switching the light on turns the fan off - unless you've somehow wired up your light switch in a two way mode, so what you think is a permanent / switched live is actually an inverse switched live. Pictures of behind the switch, and any junction boxes used would help us figure out what's going on...

Also, as this is in a bathroom all of this work is notifiable under Part P of the building regs (see the wiki for details) so I assume you've already notified the LABC?

Hi Thanks ,there was a fan there before,But will notify just in case it has not been done. Have looked in the manual & it is not very clear(or i dont understand it) Will change to Live & neutral & reply back thanks again.

 

[rebuke]

Hi Thanks ,there was a fan there before,But will notify just in case it has not been done.

It doesn't quite work that way I'm afraid...

If you're replacing an existing fan, with no new fixed cabling then that wouldn't be notifiable, however, replacing a ceiling rose with downlights most certainly is. Under Part P you have to notify your LABC *before* you do the work, they will then come out and inspect and test as they deem necessary.

For small jobs like this, it often works out cheaper to get a spark in to do it, since the notification fee is normally £100+. If you're notifying after having done the work, then the LABC is under no obligation to accept the notification, and if they do will normally charge it as a regularisation, often at a significant premium on top of the normal notification fee.

 

[andydiynot]

Hi Thanks ,there was a fan there before,But will notify just in case it has not been done.

It doesn't quite work that way I'm afraid...

If you're replacing an existing fan, with no new fixed cabling then that wouldn't be notifiable, however, replacing a ceiling rose with downlights most certainly is. Under Part P you have to notify your LABC *before* you do the work, they will then come out and inspect and test as they deem necessary.

For small jobs like this, it often works out cheaper to get a spark in to do it, since the notification fee is normally £100+. If you're notifying after having done the work, then the LABC is under no obligation to accept the notification, and if they do will normally charge it as a regularisation, often at a significant premium on top of the normal notification fee.

Wish I had never started now,well the law is the law & although the fan is working now (thanks for your help on that) the down lights were extra will give my local sparkie a call to sort for me...Perhaps this is a good message to send out to all others before making home improvements .Thanks again for expert advice.

 

[Taylortwocities]

Perhaps this is a good message to send out to all others before making home improvements .Thanks again for expert advice.

Unfortunately the message should have got to you when Part P was launched in 1995. Mr Fatscott and the rest of our illustrious government have, yet again, introduced half-baked legislation and then hope its going to work through some form of clairvoyance.

 

[niceguy235]

.......Part P was launched in 1995.

Really??

Thats me fooked then as ive only been notifying since 2005

 

[Taylortwocities]

Oh yes, that'll teach me not to rely on an old and rusty brain/..