How do you wire an extractor fan within a lighting circuit?

[rudeboy500]

Hi Guys,
How do you wire an extractor fan within a lighting circuit? I have bought a 4in extractor fan i would ideally like to feed this through the lighting circuit. I have wired Lighting circuits and Ring Circuit at college but they have not taught us how to wire an extractors fan with timer this is new to me any diagrams and instruction will be a big help
Thanks
rudeboy500

 

[rudeboy500]

See OSG 8.1 for details.

Hi MarkieSparkie,
your right looked it up i knew there were 3 zones 0,1and 2
thanks for correcting me
Rudeboy500

 

[Geoffsd]

dis agree with this part of your reply there is a reason why the fans have to be de rated and the reason is if the fan seizes to to lack of maintainance or a failure of the bearings etc which causes the fan to stop then the fan motor could over heat and catch fire this could be before a 6 amp or 10 amp mcb operates hence the reason it has been de rated i have been in a situation where this has happend and has set fire to a shop causing £89,000 worth of damage , also a fan in a toilet of a hair dressing salon luckly didnt cause much damage , and one main one was due to a fatal fire in which 3 people died in London which the spark was prossecuted , not sure what the outcome was this is the reason for derating

That may be true. Is there evidence that a 3A fuse would have prevented the outcome?

The CU fusues/mcbs are there to protect the installation cables. These fans are not supplied with fitted 3A flex.

If the manufacturers produce products which are 1A (or even ¼A) then they should fit integral fuses rather than state that another accessory be fitted to the installation which is still three times (or even twelve times) larger than necessary.

I suggest that this tragedy would be due to the manufacturers' negligence were it not for 134.1.1 allowing them a cop-out and/or to produce shoddy goods.

That's what I meant by unnecessary.