fan in bathroom

[dayrider3883]

I have installed a fan from the lighting switch to bathroom do i need to use a spur for the fan or can i go direct

 

[JUD]

We do not need to disregard Regulation 314.4 as the lighting final circuit itself complies with it as it's origin is the distribution board.

The FCU is supplied by the final circuit and itself supplies a circuit for the light and fan in the bathroom.

The reg you're referring to regarding RCD protection says that "Additional protection shall be provided for all circuits of the loacation...."

If what you're suggesting was true then surely it would say "Additional protection shall be provided for all final circuits supplying equipment in a location containing a bath or shower...." or something along those lines.

At the end of the day it's down to how each individual interprets the regulations.

 

[Deleted member 26818]

We do not need to disregard Regulation 314.4 as the lighting final circuit itself complies with it as it's origin is the distribution board.

The FCU is supplied by the final circuit and itself supplies a circuit for the light and fan in the bathroom.

The reg you're referring to regarding RCD protection says that "Additional protection shall be provided for all circuits of the loacation...."

If what you're suggesting was true then surely it would say "Additional protection shall be provided for all final circuits supplying equipment in a location containing a bath or shower...." or something along those lines.

At the end of the day it's down to how each individual interprets the regulations.

So what exactly is the circuit the FCU supplies, is it not a final circuit?
Why would the wording be all final circuits? That would then allow distribution circuits to be unprotected.
In fact, it could be that the Regulation is not just for circuits that supply equipment in such locations, but also for circuits that pass through to supply equipment in other locations.
It used to be in the 16th edition, as you probably know, that in zones 0, 1 and 2, cables either surface mounted, or concealled in walls at a depth less than 50mm, had to have additional protection, if they did not supply equipment in their respective zones.
It may well be down to how an individual interprets the Regulations, although how you can interpret 314.4, and the very clear information provided in Appendix 15, in any other way than as it is written, is a mystery to me.
Of course, it may just be the case that you do not want to comply with 701.411.3.3 for whatever reason and are trying to make excuses?

 

[JUD]

So what exactly is the circuit the FCU supplies, is it not a final circuit?

It's a circuit as defined in Part 2 the regulations. The final circuit already exists and complies with Regulation 314.4 as I said in my previous post.

Why would the wording be all final circuits? That would then allow distribution circuits to be unprotected.

The reg is for all circuits of the location, not all circuits supplying the location.

In fact, it could be that the Regulation is not just for circuits that supply equipment in such locations, but also for circuits that pass through to supply equipment in other locations.

If other circuits were passing through the location they would probably be concealed in walls or above ceilings so they would not strictly be in the location. If these circuits were installed before the requirement for RCDs then you have no obligation to bring them upto current standards as you haven't worked on these circuits.

It may well be down to how an individual interprets the Regulations, although how you can interpret 314.4, and the very clear information provided in Appendix 15, in any other way than as it is written, is a mystery to me.
Of course, it may just be the case that you do not want to comply with 701.411.3.3 for whatever reason and are trying to make excuses?

Appendix 15 is not a regulation. I'm not making excuses, an RCD FCU would comply with 701.411.3.3 as the lighting circuit would be RCD protected.

 

[Deleted member 26818]

JUD, this is becoming very tedious.
I suggest that if you can't put up then shut up.
I've answered your pointless question about Zs valus for BS1362 fuses, why won't you answer my question about what type of circuit is being supplied by the FCU?
Is it just because you know that the circuit must be a final circuit and as such is not accepted by BS7671 to be supplied from anything other than a distribution board?
A kettle meets the requirements of the definition of a circuit in Part 2, but I wouldn't call it a circuit.
I have no idea why you have stated:

The reg is for all circuits of the location, not all circuits supplying the location.

Or:

If other circuits were passing through the location they would probably be concealed in walls or above ceilings so they would not strictly be in the location. If these circuits were installed before the requirement for RCDs then you have no obligation to bring them upto current standards as you haven't worked on these circuits.

I know Appendix 15 is not a Regulation, it is there to provide information in relation to the Regulations.
Should we then ignore the Tables for time/current characteristics of overcurrent protective devices in Appendix 3, the Tables for current carrying-capacities of cables in Appendix 4, the figures for voltage drop in Appendix 12, etc. as they also are not Regulations?
Or is it we just ignore the information that doesn't tally with your point of view?

 

[Octopus]

JUD, this is becoming very tedious.
I suggest that if you can't put up then shut up.
I've answered your pointless question about Zs valus for BS1362 fuses, why won't you answer my question about what type of circuit is being supplied by the FCU?
Is it just because you know that the circuit must be a final circuit and as such is not accepted by BS7671 to be supplied from anything other than a distribution board?
A kettle meets the requirements of the definition of a circuit in Part 2, but I wouldn't call it a circuit.
I have no idea why you have stated:

Or:

I know Appendix 15 is not a Regulation, it is there to provide information in relation to the Regulations.
Should we then ignore the Tables for time/current characteristics of overcurrent protective devices in Appendix 3, the Tables for current carrying-capacities of cables in Appendix 4, the figures for voltage drop in Appendix 12, etc. as they also are not Regulations?
Or is it we just ignore the information that doesn't tally with your point of view?

Gentlemen, may I suggest that we agree that you have different interpretations of BS7671 and leave it at that!

:6:

 

[JUD]

JUD, this is becoming very tedious.

I agree and this will be my last post.

I suggest that if you can't put up then shut up.

There's no need to get offensive just because somebody doesn't agree with your point of view. Looking back through all the posts, I see that there's only you who thinks that the whole circuit needs RCD protection.

Everybody else who's commented thinks the same as I do i.e. RCD protection only necessary for the circuit in the location.

I've answered your pointless question about Zs valus for BS1362 fuses, why won't you answer my question about what type of circuit is being supplied by the FCU?


Is it just because you know that the circuit must be a final circuit and as such is not accepted by BS7671 to be supplied from anything other than a distribution board?
A kettle meets the requirements of the definition of a circuit in Part 2, but I wouldn't call it a circuit.

I've answered your question twice. Where does it say that a circuit must be labelled as a final circuit? As I've said, the lighting circuit as a whole is a final circuit and complies with Regulation 314.4.

I suppose the best way I could describe it would be a sub-circuit. I know it's not in the definitions, however the definitions in Part 2 are for the purposes of the regulations only as it says at the top of the page.

I know Appendix 15 is not a Regulation, it is there to provide information in relation to the Regulations.

You use Appendix 15 as an argument that all circuits must start at a distribution board. It refers to Regulation 433.1. Nowhere in 433.1 does it say a circuit must start at a distribution board. If we're to take Appendix 15 as literally as you do then that means that all radial final circuits should be connected to 30A or 32A overcurrent devices because Appendix 15 says they are.

Should we then ignore the Tables for time/current characteristics of overcurrent protective devices in Appendix 3, the Tables for current carrying-capacities of cables in Appendix 4, the figures for voltage drop in Appendix 12, etc. as they also are not Regulations?

Not sure why you've brought any of that up.

Or is it we just ignore the information that doesn't tally with your point of view?

Again, I'm not alone in my point of view.


Have a read of Q2 in the link:

http://www.esc.org.uk/industry/industry-guidance/industry-guidance-on-the-wiring-regulations/alterations-and-additions-in-domestic-and-similar-premises/.

That should clear things up for you.

 

[kung]

I agree with frank sinatra ! I did it my wayyyyyyyyyyyyyy !

 

[kung]

Im expecting someone to say yer an you can shut up as well !

 

[Deleted member 26818]

Sorry, I wasn't intending to be offensive, just trying to get you to answer my question, which you now have.
I'll try and put my case as consisely as possible:
We all know that locations containing baths and showers are areas where the risk of electricution are increased.
I won't bore you with explanations as I know you are well aware of the risks.
By placing an RCD anywhere other than at the origin of a circuit, an earth fault occurring upstream from the RCD will bypass the RCD and enter the location.
As such, the RCD is only providing protection against an earth fault occuring on the part of the circuit downstream from the RCD.
If for instance a supply was taken from a RFC then any earth fault current caused by a fault in the wiring of the RFC or by any appliance plugged into the RFC, that current would bypass the RCD and enter the location.
I ask you what would be safer, installing the RCD at the DB, or somewhere along the circuit?

BS7671 defines two sorts of circuits, Distribution and Final. It does not have a definition for a sub circuit.
A fused spur meets the definition of a circuit, and also that of a final circuit, but not that of a distribution circuit.
As such if we accept that it is a circuit then we must also accept that it is a final circuit.
Regulation 314.4 as I have already pointed out, requires all final circuits to be connected to separate ways at a DB.
As such if we accept a fused spur as being a circuit, then it will not comply with BS7671.
With regard to the typographical errors in Appendix 15.
These errors were addressed in a corrigendum, and the corrigendum is available for download from the IET website here:http://electrical.------.org/wiring-regulations/updates/bs7671-2008-corrigendum-jul08.cfm?type=pdf
As can be seen, the reference to '30A or 32A' overcurrent protective device has been struck through.

 

[JUD]

I understand the point you're trying to make.

Putting aside definitions of circuits and regs about separation of circuits you have to remember the reason for the RCD in the first place, that reason being Additional protection.

The RCD is there to limit the touch voltage between exposed and extraneous-conductive-parts of the location to ≤ 50V should an exposed-conductive-part become live while a person is touching it and another exposed or extraneous-conductive-part simultaneously.

This is achieved weather the RCD is at the origin of the circuit or not.

Good point about the corrigendum by the way. I've actually already got it on the computer but forgot all about it.

No hard feelings I hope.

I'm sure Luke Skywaler will be here soon to correct us both....:hurray:

 

[kung]

Yer and it will prob take luke skywalker with the force with him to understand fully the regs 100%

 

[Deleted member 26818]

JUD how will an RCD limit touch voltages if the fault is on a part of the circuit before the RCD?
The RCD will not detect the fault, and so will not operate.

 

[Octopus]

I'm very bored with this now. Where's a certain contraversal poster when you need him/her?

 

[telectrix]

if you mean like sky******, he's banned.

 

[JUD]

JUD how will an RCD limit touch voltages if the fault is on a part of the circuit before the RCD?
The RCD will not detect the fault, and so will not operate.

A fault current on a part of the circuit before the RCD will take the path of least resistance i.e back to earth through the cpc and along the normal earth fault loop path and, if Zs for the circuit is within limits which it should be, take out the main breaker/fuse.