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Topic Title: 701.411.3.3
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Created On: 27 April 2014 10:34 AM
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 27 April 2014 10:34 AM
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alanblaby

Posts: 375
Joined: 09 March 2012

Ensuite with a shower, having a new saniflow toilet fitted.
Supply is via a FCU outside the room,the present supply is not RCD protected. The Saniflow is double insulated, with no earth cable in the supplied flex cable.
The saniflow and cable are completely boxed in, and not accessible without taking apart the panelling.They are also well outside of the Zones.
Piping is all plastic.

Is there a need to supply via a RCD fused spur, to comply with the above Reg.?
It would appear to be it does need to be RCD protected, even though outside the zones, and with no electrical parts accessible.
My thinking is that there is such a very low risk of any shocks from the equipment, that RCD protection could be omitted, but for the £15 cost of a RCD spur, I'm not too worried about supplying one.

Any thoughts?
Ta
Alan.
 27 April 2014 05:45 PM
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davebarman

Posts: 285
Joined: 27 February 2006

Done and Dusted then.

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Never knock on Death's door. Ring the doorbell and run like hell, he hates that!
 27 April 2014 05:49 PM
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daveparry1

Posts: 6227
Joined: 04 July 2007

Hardly any need but I would probably fit an rcd fcu. (don't tell Spin though!) lol
 27 April 2014 08:51 PM
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aligarjon

Posts: 2849
Joined: 09 September 2005

My take would be if its inside boxing it isn't in the room.
manufacturers instructions ?

Gary

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Specialised Subject. The Bleedin Obvious. John Cleese
 30 April 2014 01:05 AM
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mapj1

Posts: 2859
Joined: 22 July 2004

just because the cable has no earth core doesn't mean a live to terra firma / live to person shock current could not arise. For example, if the unit blocked and flooded the motor internally and leaked a continuous thread of water with some impurities in onto a floor trodden by bare feet.
I do agree its unlikely but perhaps not as unlikely as you may think when compared to being dismantled with the power on - well not in my house any way.
I'd be inclined to fit RCD.
Mike

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regards Mike
 30 April 2014 09:41 AM
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OMS

Posts: 19693
Joined: 23 March 2004

Start with the concept of "wet and naked"

Then review the Emma Shaw case

Then recognise the fault scenario Mapj1 highlighs above.

Then consider "all circuits of the location"

Regards

OMS

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Failure is always an option
 01 May 2014 08:34 AM
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lyledunn

Posts: 624
Joined: 13 August 2003

You do not need to fit a RCD to comply with the stated regulation. But then on RCDs the electrical contracting industry is ahead of BS7671 in that we have considered the merits of RCDs and have decided to fit them even in situations where the regulations do not require them. A good thing too!

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Regards,

Lyle Dunn
 01 May 2014 09:49 AM
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OMS

Posts: 19693
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Isn't the operative word in Reg 701.321.1 "may" - as in " .......and fixed partitions may be taken into account........" - when undertaking the assessment of general characteristics and classification of the external influences.

BS 7671, quite correctly, allows the "designer" to make the assessment and come up with a compliant solution.

So, I would say you may need an RCD to comply with the requirements of BS 7671 in the above scenario - it depends on how you define the boundary of the "location".

The extreme example I use is the provision of a shower in a B&Q shed - it might be 20m in each direction to the bounding enclosure of the location, you could have sockets up to 3000mm from the tub and lighting circa 6m above the tub - what extent of RCD provision would BS 7671 require ?

Regards

OMS

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Failure is always an option
 01 May 2014 10:33 PM
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antric2

Posts: 1061
Joined: 20 October 2006

The RCD will be benificial in protecting the cable that most probably is being run under the onsuite and popping up from the floorboard in the boxed area to supply the saniflo.also, the saniflo cable will need to be jointed so I presume a wiska box will be used which could have the million to one chance of getting wet if it flooded
Eitherway an RCD fused spur would be a good idea from a safe and good workmanship point of view.
Regards
Antric
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