does doorbell wired as appliance need certification?

[fishkeeper]

If a wired doorbell is connected as per manufacturers instructions and is powered by a 3A fused plug as an appliance, does it need inspection or certification?

i.e. what if the mains 2 wire power lead for the transformer (which steps down power to the bell wire circut) goes to a household 3 prong plug (no bell unit earth wire so earth not connected) which has a 3A fuse and is plugged into a wall socket and can optionally be removed from the socket or switched off just like a vacuum cleaner or a TV or something. The point being if the bell unit is not directly wired into the house circuit am I right in thinking that would count legally as an appliance and not need certification?

 

[bernardgreen]

If wired to a 13 amp plug ( fitted with 1 or 3 amp fuse ) then no certification is required.

Ensure all terminals of the transformer are covered so there are no exposed live metal screw heads.

Also avoid low cost transformers bought on line from some dubious overseas supplier. In some of the these items the insulation between LV (230 volt mains) and ELV ( 12 volt ) windings is not to the required minimum standard and thus the door bell could become Live and be a potentially fatal hazard to visitors.

 

[Taylortwocities]

I must invite my mother-in-law round to test my "new" doorbell installation

 

[fishkeeper]

Thanks for answering Bernard that is good news, I am putting my trust in this item from DoorchimesUK.co.uk. I will certainly be careful of any signs of electrical shorting though now you mention it. Something of that ilk seems to have happened to my Toshiba CRT TV.


Dont want to electrocute my delivery persons ... Taylor *wags finger* ;o)

 

[ericmark]

Your question I would assume ask what is a circuit as far as Part P is concerned. It would seem this is different to a circuit BS7671 wise. So replacing a socket with a FCU and then running cables to 4 sockets as far as BS7671 goes is a new circuit but as far as Part P goes is not.

So Part P wise if there is already a transformer and you run SELV cables to sockets clearly not the same type as used for LV so a bell can be plugged in when required the that is not a new circuit.

The same applies to BS7671 as there is no over load device installed it's not a new circuit.

The question has been raised many times if a FCU is wired but nothing comes off that FCU when latter something is added does that form a new circuit? Most with a FCU would say no but many with a un-used MCB in a consumer unit would say yes which is really the same thing.

So personally as far as Part P goes I would consider it does not need any completion or compliance certificate.

As to BS7671 I would personally say any work on the low voltage should have a minor works certificate but for the separated extra low voltage most the boxes for a Minor works certificate would be rather pointless and although in theroy one should be made in practice I would not bother.

I suppose in theroy we should get a minor works certificate when a telephone point is installed but to be frank I think it would be rather pointless.

 

[ban-all-sheds]

Your question I would assume ask what is a circuit as far as Part P is concerned.

That would be a meaningless question.

It would seem this is different to a circuit BS7671 wise. So replacing a socket with a FCU and then running cables to 4 sockets as far as BS7671 goes is a new circuit but as far as Part P goes is not.

That doesn't make sense - Part P does not concern itself with what is or is not a new circuit.

This is Part P:

 

[ban-all-sheds]

i.e. what if the mains 2 wire power lead for the transformer (which steps down power to the bell wire circut) goes to a household 3 prong plug (no bell unit earth wire so earth not connected) which has a 3A fuse and is plugged into a wall socket and can optionally be removed from the socket or switched off just like a vacuum cleaner or a TV or something.

Is that how you actually want to install your doorbell?

 

[fishkeeper]

It'll do for now all-sheds. Part P certification is a lot of work and expense for a little job like this, not many electricians would bother. One local sparks told me he would not even take a job for less than £150.

In due course if I have other work done which needs certification then I may get someone to install the doorbell unit mains lead to a new FCU if I can get that added to the existing wall socket and then they can certify that as part of the bigger job.

I believe its a safe way to set up a doorbell, I just want to be sure its also legal and I wont get a ticking off from any electricians who see it, not to mention nicked, which would be embarassing.

 

[ban-all-sheds]

It'll do for now all-sheds.

That's not really an answer to the question I asked.

Part P certification is a lot of work and expense for a little job like this

Part P does not call for any certification.

In due course if I have other work done which needs certification then I may get someone to install the doorbell unit mains lead to a new FCU if I can get that added to the existing wall socket and then they can certify that as part of the bigger job.

So that seems to be saying that you don't want to install it as you're proposing, you want it on an FCU.

So why not do it that way from the start?

 

[JohnW2]

At least in terms of the OP, is not this discussion making a mountain out of a molehill?

To the best of my knowledge, there are NO circumstances in which plugging something (anything) into an existing 13A socket is notifiable.

Approved Document P points out that 'fixed wiring' (which I presume would include wiring to a door bell) comes within the scope of Part P even if it is connected to the supply by a 13A plug/socket - but all that means is that, if (as usual) compliance with Part P is to be demonstrated by complying with BS7671, a Minor Works Certificate should theoretically be completed (although, as has been suggested, I somewhat doubt that many people would bother). It certainly doesn't mean that the work is notifiable.

Kind Regards, John

 

[fishkeeper]

OK so its not notifiable, thanks John.

sheds, ideally an FCU but on the other hand a plug is much simpler as a DIY job as well. I was under the impression that adding an FCU or changing a socket for a socket plus FCU would constitute a change to wiring and therefore be notifiable and require certification, is that not the case? It is in a hallway leading to a front door, away from any special areas.

 

[JohnW2]

I was under the impression that adding an FCU or changing a socket for a socket plus FCU would constitute a change to wiring and therefore be notifiable and require certification

No. In fact, since April 2013 (in England. not Wales) very little electrical work remains notifiable - essentially just replacement of CUs, installation of 'new circuits' (the definition of which is subject to some debate) and certain works in 'special locations', such as certain zones of bathrooms.

All electrical work has to be undertaken in accordance with Part P of the Building Regs (which essentially just says that it must be done safely) and, strictly speaking, any electrical work undertaken in compliance with the Wiring Regulations (aka BS7671) should result in a 'certificate' from the person who undertook the work, but that's nothing to do with the requirement for notification.

Kind Regards, John

 

[winston1]

Also avoid low cost transformers bought on line from some dubious overseas supplier. In some of the these items the insulation between LV (230 volt mains) and ELV ( 12 volt ) windings is not to the required minimum standard and thus the door bell could become Live and be a potentially fatal hazard to visitors.

Why not earth bond one side of the secondary winding if worried?