Adding Extractor Fan to Lighting Circuit

[0ddba11]

Hi all, this is my first post here so a big hello to everyone first

Now down to business...

I am gutting my bathroom and as part of the renovation I'm adding electric underfloor heating, a shaver socket, and an extractor fan.

I've been sifting through posts here and through various information on the web surrounding the amendments in the 17th edition of BS 7671 and I have a few queries.

I intend to take a spur off of the ring main and through the bathroom wall for the Thermastat (which is IP20 rated and will be 'out of zones') for the underfloor heating. I then intend to wire the extractor fan (inc. timer) and shaver socket into the lighting circuit.

My question is, BS7671 now suggests that ALL bathroom electrics should be protected by a 30 mA RCD. Since my house was built pre 2008 I only have a 30 mA RCCB on my ring main so my lighting circuit is not protected, so do I need to change it so that it is as a result of these works, or can I just add to the existing setup?

Also, with regard to the extractor fan, do I HAVE to have a triple pole isolator for the fan to comply with regs or is this just a recommendation / nice to have? Does it still have to be of the pull cord variety if it's going to be in the bathroom (even if its out of the zones)?.

I will of corse be getting a professional sparky to check everything after I've finished, but it would be nice if I didn't have to change anything!

 

[flameport]

A 30mA RCD is required. This could be added in the consumer unit, or a a separate item elsewhere on the circuit.

Isolator for the fan is not essential, but would normally be installed, particularly if there is no natural light in the room where the fan is.

Switches in a bathroom do not need to be a manky pull cord (including light switches) provided they are located appropriately.

Someone checking the work afterwards is no use - it must be notified before any work is started.

 

[Steve]

Hi all, this is my first post here so a big hello to everyone first

Now down to business...

I am gutting my bathroom and as part of the renovation I'm adding electric underfloor heating, a shaver socket, and an extractor fan.

//www.diynot.com/wiki/electrics:part p

I've been sifting through posts here and through various information on the web surrounding the amendments in the 17th edition of BS 7671 and I have a few queries.

good

I intend to take a spur off of the ring main and through the bathroom wall for the Thermastat (which is IP20 rated and will be 'out of zones') for the underfloor heating. I then intend to wire the extractor fan (inc. timer) and shaver socket into the lighting circuit.

My question is, BS7671 now suggests that ALL bathroom electrics should be protected by a 30 mA RCD. Since my house was built pre 2008 I only have a 30 mA RCCB on my ring main so my lighting circuit is not protected, so do I need to change it so that it is as a result of these works, or can I just add to the existing setup?

You need to RCD any new work in a bathroom. All new work must comply with current regulations. If the Ring main is RCD protected, the UFH will be fine added on. But the lighting circuit will need RCD protecting, if only where it enters the bathroom using a RCD fused spur.

Also, with regard to the extractor fan, do I HAVE to have a triple pole isolator for the fan to comply with regs or is this just a recommendation / nice to have? Does it still have to be of the pull cord variety if it's going to be in the bathroom (even if its out of the zones)?.

A TP isolator is required if its a timer fan. The isolator can be wall mounted above the door outside the room, or right beside the fan (out of zones). Either are common.

I will of corse be getting a professional sparky to check everything after I've finished

Thats not how it works:
//www.diynot.com/wiki/electrics:part p

 

[SparkyNinja]

I only have a 30 mA RCCB on my ring main....

Is your consumer unit of the split load type or do you just have a designated RCD fr the ring?

do I HAVE to have a triple pole isolator....

Isolation for the fan is required, but there are options like inline fans for example.

 

[SparkyNinja]

I will of corse be getting a professional sparky to check everything after I've finished, but it would be nice if I didn't have to change anything!

Of course

 

[0ddba11]

A TP isolator is required if its a timer fan. The isolator can be wall mounted above the door outside the room, or right beside the fan (out of zones). Either are common.

Yes, it will be a timer fan. And just for clarification, does it have to be right next to the fan, or can it be on another wall that's out of zone, because the fan itself (being IPX4) might end up going in to Zone 1 or 2 where a TP isolator would not be allowed.

Thats not how it works:
//www.diynot.com/wiki/electrics:part p

Brill! - I missed this page altogether, very helpful thank you, I am now curious about the LABC fee, whether it is less costly to just get a sparky who is registered with a self certification scheme to do the work?

 

[0ddba11]

Is your consumer unit of the split load type or do you just have a designated RCD fr the ring?

Split load type with cartridge fuses.

 

[ban-all-sheds]

I am now curious about the LABC fee, whether it is less costly to just get a sparky who is registered with a self certification scheme to do the work?

It varies from council to council - look at the website of yours.

Even if yours is one of the ones that plays by the rules it will probably be cheaper to get a registered electrician than pay the LABC fee.

Split load type with cartridge fuses.

That's unusual....

 

[securespark]

I've seen a few Legrand ones with BS1361 holders instead of MCB's installed.

I've even seen a Wylex split-load 3036 board!

 

[0ddba11]

Oh, maybe I've misunderstood what split load is?

It's a Hager board with 5 RCCB protected slots, and 5 unprotected.

I have 2 ring mains, cooker and central heating thermostat running off the RCCB side and 2 lighting & emersion heater running off the other side.

All circuits have BS1361 holders, I would like to change them for the trip style some day...

 

[Steve]

Photo?

 

[0ddba11]

Sure

 

[londonboy]

Split load type with cartridge fuses.

That's unusual....

Seen loads of them... oh look just like this one

Certainly surprised me the first time I encountered them.

 

[0ddba11]

Just had a bright idea...

Is there such a thing as a 6 amp MCB fuse with built in 30mA RCD so that I can remove the old 5 amp cartridge style on the lighting circuits then my bathroom ends up with an RCD protected lighting circuit?

 

[RF Lighting]

Yep there certainly is. They are not the cheapest things around, but no where near as bad as they used to be.


http://www.tlc-direct.co.uk/Products/HGADN106.html