Wiring A Timed Bathroom Fan...

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The instructions that came with my bathroom fan (Marley NDX100T) say that it must be isolated with a double pole isolation switch.

The wiring diagram shows the pull switch, bathroom lights and fan all isolated with this switch and this is how it has been wired.

The instructions are, however, dated October 2004. I have seen recommendations on here to use a triple pole isolation switch for timed fans.

Are my instructions out of date?

Is triple pole the latest regulation?

Will my fan fail inspection?
 
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Well that would completely isolate the fan.

And the lights at the same time, which might be a bummer if you wanted to work on the fan...

So you should use a triple-pole isolator between the light and the fan - the expectation is that you'll have loop-in wiring in the ceiling and take permanent live, switched live and neutral from the light. If you loop through the switches you can just as easily take L/SL/N from there.

Because it's L/SL/N you use 3-core & earth cable, through a triple pole isolator to the fan.

The fun comes when the maker's instructions tell you to put it on a 3A fuse...


BTW - when you say "inspection" - have you or do you plan to notify the council that you're fitting this fan?
 
If you use one of these http://www.screwfix.com/prods/83049/Electrical/RCDs/Volex-13A-RCD-FCU to supply bathroom lights as now all items in a bathroom need RCD protection then you can fuse to 3 amp. Fans do go wrong and using one of these http://www.screwfix.com/prods/81838...Moulded/Volex-Range/Volex-6A-Fan-Isolation-Sw will allow you to switch off the fan and still use the light.
Some makes of isolator include a bracket and lock so it can be locked off. Although normally a hole in fuse carrier which would also allow a lock to be fitted.
What you need to consider if you have to fit the RCD-Fused connection unit is there really any point also fitting an isolator?
I would talk to either the registered electrician doing the work or the local council building control who ever is filling in the completion certificate under Part P.
 
Well that would completely isolate the fan.

And the lights at the same time, which might be a bummer if you wanted to work on the fan...

So you should use a triple-pole isolator between the light and the fan - the expectation is that you'll have loop-in wiring in the ceiling and take permanent live, switched live and neutral from the light. If you loop through the switches you can just as easily take L/SL/N from there.

Because it's L/SL/N you use 3-core & earth cable, through a triple pole isolator to the fan.

The fun comes when the maker's instructions tell you to put it on a 3A fuse...


BTW - when you say "inspection" - have you or do you plan to notify the council that you're fitting this fan?

Some explanation required.

1) Ericmark - there is an RCD fitted next to my fuse box that covers all circuits in the house.

2) BAS - The bathroom has been extensively altered. I asked a couple of questions on here about the drain from the toilet and was advised that it fell under building regs and to notify the council. This I did and applied for a regularisation certificate. The council inspected, said I had to fit a 40mm drain to the shower (not 32mm). This I did, they reinspected said everything was fine but said I had to have an electrician test the fan, once I fitted it, so they could issue the certificate. That's the stage I'm at now. I was having a look around this forum to see if I'd missed anything before booking an electrician.

Ever the cautious one, I think I'll change to a triple pole isolator switch. I did think it was a bit odd that lights were isolated as well.

The makers instructions say "When supplied from a 5 amp lighting circuit no local fuse is required." I take it I am OK to stick by this with a triple isolator switch?
 
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From what you say only a triple isolator switch is required.

From what I have read you need to provide the LABC with an installation certificate this can only be filled in by the person who has done the work and is available with provision for three signatures.
Designer (i.e. You)
Installer (again you)
Inspection and testing (the electrician you hire)
See http://www.theiet.org/publishing/wiring-regulations/forms/formspdf6.cfm?type=pdf for the up to date forms without online edition written all over them.
You could of course inspect and test yourself and if the LABC don't agree with your findings they then can re-test at their expense.
The Part P document is available at http://www.planningportal.gov.uk/england/professionals/en/4000000001253.html and if you read page 11 section 1.26 it seems to me you don't have to pay for the test.
Don't take my word read it yourself.
Sorry to say some local authorities are not very helpful while others really do work for the money they charge. As a qualified electrician we do not get any problems but we do hear so stories how councils seem to go OTT.
See what others say from other areas Flintshire in North Wales was helpful to me but of course they were not likely to find any faults.
Eric
 
GaryMo is correct in fact if you read Part P is does say how even this may not be required (1.13) although BS7671:2008 does not agree with this.

I often wonder what the council does if you submit a certificate which is not up to the required standard.

Reading Part P they are responsible and would then need to do it themselves? Do read 1.24 to me that says they (the LABC) are responsible for site safety and as such I would say they should fill in and provide the certificate. But 1.27 says they will not fill in the certificate which seems a contradiction to what it says as to responsibility for site safety.

As I have said as skilled persons we do not get involved in this I would love to hear from any DIY person who has and find out what really happens.

Eric
 
2) BAS - The bathroom has been extensively altered. I asked a couple of questions on here about the drain from the toilet and was advised that it fell under building regs and to notify the council. This I did and applied for a regularisation certificate.
Ah - the perils of not ensuring that you know what laws apply to what you do before you do it....


The council inspected, said I had to fit a 40mm drain to the shower (not 32mm). This I did, they reinspected said everything was fine but said I had to have an electrician test the fan, once I fitted it, so they could issue the certificate. That's the stage I'm at now. I was having a look around this forum to see if I'd missed anything before booking an electrician.
You really really must find out what sort of certificate they want from the electrician.

If it's a PIR then no problem (assuming you don't **** up the installation), but if they want an EIC you'll find it virtually impossible to get one of those unless the electrician installs the fan.


The makers instructions say "When supplied from a 5 amp lighting circuit no local fuse is required." I take it I am OK to stick by this with a triple isolator switch?
Going by the letter of their instructions you can't put it on a lighting circuit which is on a 6A MCB, which is ludicrous. You should assume it will be OK, but write and ask them to confirm.

I take it you are aware of the 17th Edition requirements for RCD protection of bathroom circuits and of concealed cables?
 
From what I have read you need to provide the LABC with an installation certificate this can only be filled in by the person who has done the work and is available with provision for three signatures.
Designer (i.e. You)
Installer (again you)
Inspection and testing (the electrician you hire)
AFAICT, in practice electricians will not sign the I&T part of an EIC if they do not believe that the person(s) who signed the other parts are qualified to do so.


You could of course inspect and test yourself and if the LABC don't agree with your findings they then can re-test at their expense.
Nope - too late for that as he didn't notify in advance via a Building Notice or Full Plans Submission, describe how he would comply with Part P and pay the fee.

Now he is at the mercy of his LABC and will have to do whatever they ask.


if you read page 11 section 1.26 it seems to me you don't have to pay for the test.
For work properly notified in advance.

mosaix is into the realms of regularisation, so none of the "they should do this" parts of Approved Document P will apply.


GaryMo is correct in fact if you read Part P is does say how even this may not be required (1.13) although BS7671:2008 does not agree with this.
Bear in mind two things:

1) You don't have to do anything which Approved Document P says - it is not the law.

2) Even if you do follow it there's no requirement to comply with BS 7671.


I often wonder what the council does if you submit a certificate which is not up to the required standard.
You can't, not if you follow the process properly, because if you notify in advance you will have to say as part of your submission how you intend to comply with Part P.

IF you choose to comply with it via the route of complying with BS 7671, and you don't meet that standard then you've not done the work in the way you told them you would and I guess they'd ask for it to be re-done.


Reading Part P they are responsible and would then need to do it themselves? Do read 1.24 to me that says they (the LABC) are responsible for site safety and as such I would say they should fill in and provide the certificate. But 1.27 says they will not fill in the certificate which seems a contradiction to what it says as to responsibility for site safety.
It only seems a contradiction if you don't understand any of the following
  • that Part P is part of the Building Regulations, not the Wiring Regulations
  • that EICs & MWCs are not Building Regulations completion certificates
  • that there is no legal requirement to comply with the Wiring Regulations
  • that you don't have to comply with the Wiring Regulations in order to comply with the Building Regulations.
1.27 says that they won't issue an EIC. And they won't - they've not been paid to - they've been paid to check compliance with the Building Regulations and to issue a Building Regulations completion certificate.
 
Everyone - thanks for your help.

My next steps:

1) Triple pole isolation switch.

2) Contact council and find out exactly what kind of certificate they require.
 

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