bathroom extractor with timer, and rcd fcu

[Steve34]

hi guys, i've been asked to put a bathroom extractor with timer, now i haven't done one for ages but it was always a simple matter of 3 core from the light through a 3 pole isolator switch to the fan, but the property has an old fuse board with no rcd protection, i am also led to believe that most timer extractors need to fused down to a 3A?

now i've never used an rcd fcu before, but if i cut into the feed just before the light and added the rcd fcu with a 3A fuse, and did the fan isolator as normal, would that be ok, or am i over complicating things?

thanks for any advise. steve

 

[telectrix]

that was my contention. even though the fan is in the loft, the existing lighting circuit is being modified, so RCD protection for the circuit must be installed if not already present. i tend to feed fans in dependently of the light, but even so, they are still generally fed from the same circuit as the light.

 

[HandySparks]

Does it actually matter whether the fan is situated in the loft or the location?
Unless the fan is to be permanently on, or there is to be a separate supply and switch.
Somewhere along the way, the circuit feeding the light in the location will be extended.

I contend that if there's no new wiring or accessories in the bathroom and the fan supply is just connected to existing wiring in the loft, then there's no need to add RCD protection. The only change to the bathroom is that the new fan happens to be extracting air from it.

By way of illustrating my point, if you added a second ceiling light to a bedroom which happens to be on the same circuit as an adjacent bathroom (with all new wiring running on the surface in the loft), would you feel compelled to RCD protect the circuit?

 

[Guitarist]

Guitarist, could you please explain why you have quoted my post and then posted what you have?
As far as I can work out the only bit which appears relevant to either the OP or my post is the information Elecsa have provided you: i.e. "You are only reponsible for the work YOU carry out".
Perhaps other's hold a different opinion, but the information Elecsa have provided is no different to what I would provide, and have provided in this instance and on many other occasions.

As far as I'm aware the OP does not intend replacing a fan or a shower.
As such I have difficulty grasping why you believe such work has any relevance to either the OP or my post?

Again as far as I'm aware (I can only go by what the OP has posted), the OP is intending to extend an existing circuit, by installing a fan into a location containing a bath or shower.
Unless the OP intends the electricity to walk to the fan (I asssume they don't as they have made referrence to 3core from the light), then the addition will entail the introduction of new cabling.

I don't particuarly want to be rude, but if you do intend in the future to quote any of my posts, I would prefer it if your post actually had some relevance.
Thank you.

Apologies if I misread your post. I believed that you were saying that once you alter a circuit, you are responsible for protecting that whole circuit. I was merely pointing out that we are only responsible for work that WE carry out.
Regarding the OP, there was indeed a point where having the extractor fan in the loft was mentioned. My opinion is that if the fan is not installed in a room containing a bath or shower (ie the loft), no new cabling is introduced into that location, and the cabling is surface mounted, then regardless of whether you connect to the lighting circuit which then goes on to a bathroom, you are not obliged to install RCD protection.
Again, I'm sorry for misreading what you wrote.

 

[Deleted member 26818]

Andy:
Whilst I am quite willing to accept that providing RCD protection to the lighting circuit because you have added an extra light in a bedroom and the same circuit supplies the bathroom, is a bit over the top.
The fact remains, that the requirement is to provide 30mA RCD protection for that circuit.
If you make an addition or alteration to that circuit irrespective of where that addition or alteration is, then if you want your work to comply, you would have to provide the required 30mA RCD protection.
Would you replace a CU and not provide 30mA RCD protection for a shower circuit because your work is outside of the location?

Getting back to the OP, installing an inline fan in the loft and supplying and controling it from a circuit that is not of a special location is fine, no 30mA RCD protection required.
However if the fan although itself not in the location, is to be supplied and or controlled from either the bathroom light or light switch, I connot see how you could make yourself believe that you are not adding to or altering the bathroom lighting circuit?
To my mind, if you're prepared to bend the Regulations that much, you might just as well not bother and install the fan in the bathroom.

Guitarist:
No I'm nefinately not stating that you would be responsible for the whole circuit if you alter or add to it.
What I'm stating, is that these particular circuits require 30mA RCD protection.
If you alter any part or make an addition, in order for your alteration or addition to comply, you must protect the circuit as required.
If you were to alter or add to a normal socket circuit, there would be no requirement to provide 30mA RCD protection for the rest of the circuit, as there is no requirement for the circuit to so protected in BS7671.
30mA RCD protection if applicable, would only be required for the cables and sockets you installed.
However if that socket circuit were in either an agricultural or horticultural installation, you would have to provide 30mA RCD protection for the circuit, as that is the requirement.
Providing the required 30mA RCD protection, in no way implies that you have taked responsibility for that circuit, you would still be only responsible for your addition or alteration.

 

[Guitarist]

Spin, I'm glad we agree on at least some of the issues raised here. While I do not agree entirely with your thinking here, I do have the greatest respect for your knowledge and experience.