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Topic Title: 13amp fused RCD
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Created On: 10 April 2017 03:48 PM
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 19 April 2017 09:09 PM
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spinlondon

Posts: 5484
Joined: 10 December 2004

Andy, as far as I am aware, you have not asked any question for me to avoid.
Sorry Andy it can you quote the reference in Regulation 110.2 which mentions TVs?
No I would not be happy, but yes a one way DB positioned just outside the location would comply.
My reading of BS7671's definition of a circuit is: that a number of things which are not circuits satisfy the definition.
This list is not exhaustive: TV, fridge, computer, vacuum cleaner, kettle, printer, bedside light, washing machine, microwave, sky satalite box, lathe, welder, battery charger, toaster coffee maker, portable radio cassette player, grinder, drill, router, belt sander, inspection lamp, compressor, bench grinder, etc.
Use of an FCU may well satisfy the BS7671 definition of a circuit, however we are required to connect each final circuit to a separate way in a DB.
 19 April 2017 10:23 PM
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AJJewsbury

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Sorry Andy it can you quote the reference in Regulation 110.2 which mentions TVs?

Try 110.1.2 (iii)

Use of an FCU may well satisfy the BS7671 definition of a circuit, however we are required to connect each final circuit to a separate way in a DB.

Which leaves (I think) three options - either use of a FCU is contrary to BS 7671, BS 7671's definition of a circuit is wrong, or BS 7671 regards a FCU to be a DB.

- Andy.
 20 April 2017 10:43 AM
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spinlondon

Posts: 5484
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Of course my TV is a motor vehicle, of course it's outside the scope of BS7671.
Not sure if you just haven't read thr Regs or if you are just being a troll?
Either way, can't be bothered any more.
 20 April 2017 05:35 PM
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weirdbeard

Posts: 3078
Joined: 26 September 2011

Originally posted by: spinlondon

My point being, can anyone confirm that the device is suitable for protecting fixed wiring?


You must have missed this earlier post:


Originally posted by: weirdbeard

Originally posted by: spinlondon

Yes, this information can be found in the Beama RCD handbook, table 2.

http://www.beama.org.uk/asset/...4870-A9ACFBC5C58A94A2/



Beama member BG don't agree, see the note at the bottom of page 2 of the link:

"This product can also be used in "hard" wire installation. The blanking plug must be left in place, and the cable clamp is not used when there is no external flexible cable"

http://www.bgelectrical.uk/pub...ed_Connection_Unit.pdf



The information in the BEAMA handbook may be incorrect


Agreed.

-------------------------
:beer)
 20 April 2017 06:16 PM
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AJJewsbury

Posts: 15632
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Of course my TV is a motor vehicle, of course it's outside the scope of BS7671.
Not sure if you just haven't read thr Regs or if you are just being a troll?

Eh? Or perhaps an error on your part? mis-reading 110.2 for 110.1.2?
- Andy.
 20 April 2017 06:17 PM
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weirdbeard

Posts: 3078
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Originally posted by: spinlondon

In horticultural/agricultural installations, the requirement is to provide socket circuits with RCD protection.

If we were to extend an existing socket circuit which didn't have RCD protection, we would have to provide RCD protection for all of the circuit existing and new.

Providing protection for just the extension would not comply.



There is no mention of where in the final circuit the RCD should be located, fitting an RCD socket for your extra socket should be ok in most cases, unless you intend to get involved with rewriting the customers existing health and saftey policy!

-------------------------
:beer)
 20 April 2017 07:02 PM
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AJJewsbury

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701.411.3.3 also requires RCDs on circuits passing through zones 1 and/or 2 "not serving" the location.
Is this really necessary? Does it assume one may be drilling while taking a bath?

I suspect it's related to allowance of of class 1 wiring systems (e.g. steel conduit) in bathrooms (they were previously prohibited - e.g. 601-07-01 in early editions of the 16th) and optionality of supplementary bonding - so faults on those circuits even if only passing through the bathroom, would be touchable without the mitigation of any supplementary protection.

One arguement is that a sub board would offer the same problem, however a sub board hopefully has more robust earthing.

If a local CU had more robust earthing, it would probably have much more robust line conductors too - (e.g. 6mm2 with 2.5mm2 c.p.c or 25mm2 with a 16mm2 c.p.c.) so would actually have a higher touch voltage than say a 1.0mm2 lighting circuit with a 1.0mm2 c.p.c. - and as a 'proper' submain most likely a much longer disconnection time too. So in some respects the RCD FCU on the lighting circuit might be preferable.

- Andy.
 20 April 2017 09:00 PM
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spinlondon

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Andy for the last time.
Can you quote anything anywhere in BS7671 which states as you have stated, that TVs are outside of the scope of BS7671?
Please don't quote 110.1.2(iii) which is part of a list of items within the scope, or 110.2(iii) equipment of motor vehicles.
 20 April 2017 10:43 PM
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AJJewsbury

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Please don't quote 110.1.2(iii) which is part of a list of items within the scope,

Why on earth not? Doesn't an exception to what's in scope hint just a little bit that it's out of scope?
- Andy.
 20 April 2017 11:45 PM
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spinlondon

Posts: 5484
Joined: 10 December 2004

Yeah whatever Andy, my TV is a motor vehicle so it's excluded.
Maybe your FCU is really an aeroplane?
IET » Wiring and the regulations » 13amp fused RCD

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