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Topic Title: En-Suite .
Topic Summary: Care Home .
Created On: 14 May 2013 07:28 PM
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 14 May 2013 07:28 PM
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Ampman

Posts: 1009
Joined: 06 February 2006

Got to install a light in a en-suite that will have a fixed shower installed .

Light will be out of zones ,

Do i still need an rcd ?

thinking yes , but the care home has about 40 other en suite rooms without rcd protection .

So i thinking i will rcd mine & advise on the others .
 14 May 2013 07:42 PM
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sparkiemike

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Are you just replacing a fitting, or is there new cabling for a new light?

If it is the latter then no need to RCD, otherwise I would say you need RCD protection as well
 14 May 2013 07:54 PM
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OMS

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Or you could take the approach of "all circuits of the location" it's nothing to do with zones - do yours and then they know whats required for the other 40 en suites as well

Are you just replacing a fitting, or is there new cabling for a new light?
If it is the latter then no need to RCD, otherwise I would say you need RCD protection as well


Other way round ?

Regards

OMS

-------------------------
Failure is always an option
 14 May 2013 08:46 PM
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Ampman

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yes new cable required ,

nightmare to rcd if im honest .
 14 May 2013 08:56 PM
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dg66

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Fit a class 2 fitting and note a deviation from the regs and note that a class 2 fitting provides better protection than an RCD.

-------------------------
Regards

Dave(not Cockburn)
 14 May 2013 09:14 PM
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Ampman

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very good idea ,

can i really get away with that ?
 14 May 2013 09:34 PM
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slittle

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Originally posted by: Ampman

yes new cable required ,



nightmare to rcd if im honest .


RCD FCU above en-suite door ???

Stu
 14 May 2013 09:46 PM
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dg66

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Originally posted by: Ampman

very good idea ,



can i really get away with that ?


As the designer you can do what you like as long as you can show that your deviation provides equal or better measures of safety as would be afforded by strict compliance, i would 'nt bother with an RCD for SELV light fittings either as they also provide better protection than an RCD.
Its your call as you are signing the paperwork.

-------------------------
Regards

Dave(not Cockburn)
 14 May 2013 10:07 PM
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leckie

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Double insulated, selv, good ideas.

Reminds me of recent posts regarding what boxes to tick!
 15 May 2013 09:27 AM
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OMS

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Originally posted by: dg66

Fit a class 2 fitting and note a deviation from the regs and note that a class 2 fitting provides better protection than an RCD.


Does it really - the fitting may be safe, instrinsically, but there is a reason why BS 7671 discusses all circuits of the location - note the distinction between all circuits and the concept of the appliance, accessory, luminaire or outlet.

Regards

OMS

-------------------------
Failure is always an option
 15 May 2013 10:20 AM
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AJJewsbury

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Ooh, I think I can play Devil's Advocate here

The requirement for 30mA RCDs is in reg 701.411.3.3 - i.e. it's a modification to section 411 of the main regs. Section 411 is about ADS only. If it was elected to design using section 412 entirely instead (double or reinforced insulation), then the requirement for 30mA RCDs wouldn't apply. As it's a care home it might be under effective supervision and so 412.1.3 could be satisfied (provided no-one wanted to use LSCs etc), allowing double insulation to be used as the sole protective measure (for that circuit at least).

- Andy.
 15 May 2013 11:17 AM
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OMS

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Of course Andy, why am I not suprised - but that assumes that the original designer was adopting double insulation as a sole means of protection. To retrofit a DI solution would need knowledge of the wiring systems employed - class 2 luminaire on a metal conduit enclosed circuit with a CPC present (but not terminated at the luminaire) wouldn't and couldn't be DI so the RCD would be required.

Then we look at supplementary bonding being present.

In very specific circumstances DI would make the installation of RCD's nugatory - I designed such a system for chemical washdown showers for emergency use (as they don't fall under Section 701) - I strongly recommend we don't suggest to anyone that DI systems in a care home should even enter into the design thinking, in practice though - I can't ever see there would be that degree of supervision.

Regards

OMS

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Failure is always an option
 15 May 2013 03:43 PM
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dg66

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Originally posted by: OMS

Originally posted by: dg66



Fit a class 2 fitting and note a deviation from the regs and note that a class 2 fitting provides better protection than an RCD.




Does it really - the fitting may be safe, instrinsically, but there is a reason why BS 7671 discusses all circuits of the location - note the distinction between all circuits and the concept of the appliance, accessory, luminaire or outlet.



Regards



OMS


IMO it does, an RCD wont stop a possible L-E contact, a class 2 fitting will

-------------------------
Regards

Dave(not Cockburn)
 15 May 2013 05:55 PM
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OMS

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At the luminaire, yes - from a circuit fault, no - IMO thats why BS 771 looks at the circuit of the location - not the luminaire, accessory, appliance etc.

A DI luminare doesn't create a DI system

Regards

OMS

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Failure is always an option
 15 May 2013 07:14 PM
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dg66

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So if we get a fault on the circuit, what dangers will occur that wouldnt if any other non RCD circuit in the installation had a fault?

-------------------------
Regards

Dave(not Cockburn)
 15 May 2013 07:49 PM
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OMS

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Well any direct or indirect contact resulting from the failure of basic protection or fault protection or occuring from the carelesness of users.

So we may apply any of the measures in sections 411 to 414, but the RCD is still required as a backstop - ie it's for Additional Protection

Regards

OMS

-------------------------
Failure is always an option
 15 May 2013 09:44 PM
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leckie

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That, Mr OMS, is a fantastic summary of the requirements.
 15 May 2013 10:41 PM
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John Peckham

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I would agree with OMS in that it is Additional Protection and as it says on the tin it is Additional to other measureless of protection. Generally I would suggest it is easier to comply with the regulations than not to, Rectum Protectum. Just put an RCD fused connection unit over the entrance door and supply the lighting from that, as suggested by Stu above.

-------------------------
John Peckham

http://www.astutetechnicalservices.co.uk/
 15 May 2013 10:59 PM
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dg66

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Originally posted by: OMS

Well any direct or indirect contact resulting from the failure of basic protection or fault protection or occuring from the carelesness of users.



So we may apply any of the measures in sections 411 to 414, but the RCD is still required as a backstop - ie it's for Additional Protection



Regards



OMS


whilst i agree an RCD will protect against the scenarios you mention, IMO additional protection is not required for these reasons, if that were the case every circuit regardless of location would require RCD protection for the scenarios you mention, i dont believe the regs cover carelessness by users, i've never seen this mentioned in the regs and as for direct contact ,i cant see this occuring in the location unless someone takes the fitting to bits and pokes their fingers where they dont belong, and indirect contact, well as its class 2 i dont see that as a problem (contact with a part thats become live due to a fault)

-------------------------
Regards

Dave(not Cockburn)
 16 May 2013 09:44 AM
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AJJewsbury

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So we may apply any of the measures in sections 411 to 414, but the RCD is still required as a backstop - ie it's for Additional Protection

Odd that 701.411.3.3 isn't numbered 701.415.1.something then?
- Andy.
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