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Topic Title: EICR Codes
Topic Summary: Advice ,
Created On: 03 April 2013 05:23 PM
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 03 April 2013 05:23 PM
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Ampman

Posts: 1021
Joined: 06 February 2006

Evening ,

Few codes i need advice on , Testing a shop ,

Found sy cables ( Braiding ) Not earthed code ?

Twin and earth cables on metal tray work ( Tray not Earthed ) ?

Thanks

Above installation done in 2004
 03 April 2013 05:34 PM
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Parsley

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Is the tray an exposed conductive part?

Is the braiding of the sy a CPC?

No codes in my opinion but i'm sure others may disagree.

Regards
 03 April 2013 05:49 PM
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Ampman

Posts: 1021
Joined: 06 February 2006

Sy outer braiding not used as cpc , just good practice to bond it down i do

Tray work i measured it back to MET >23k , But lots of sharp edges etc...

Where twin could quite easily be snagged , again my opinion but i would of bonded it if it was my install .

cheers
 03 April 2013 07:35 PM
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dickllewellyn

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Joined: 19 March 2010

If you had twin and earth cables in a metal stud wall, would you bond all the studs? Or metal ceiling joists?

I would probably be inclined to bond the braid of the Sy if I were installing, otherwise just use YY if the braid is not being utilised anyway. On an inspection though, what problem is it causing? What regulation is it breaking?

-------------------------
Regards
Richard (Dick)

"Insert words of wisdom and/or witty pun here"
 03 April 2013 07:40 PM
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Ampman

Posts: 1021
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No problem at this time ,

Just get paranoid if i dont report it and something happens ,

ie , A cable gets pierced & makes something live ,

Different opinions i suppose ,
 03 April 2013 08:56 PM
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Parsley

Posts: 1034
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If it really is an extraneous conductive part then it will need bonding not earthing. The problem is the poor quality of tray work.

Regards
 04 April 2013 08:22 AM
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leckie

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Regarding sy cable, I was told during an assessment by niceic many years ago that the braid requires bonding because if the cable is hit, the braid could become live and exposed. You can use a proper gland or piggy tail the braid. The niceic used to go on about if one event could cause danger then the installation was non compliant, but not two events. Not heard that mentioned for a long time so I don't know if that is still there take on it.

Is the braid an exposed conductive part? If you used pvc stuffing glands and the braid has the pvc cover over it, is it an exposed conductive part? is the braid a screen or mechanical protection? If there is no requirement to bond an sy braid then is there would no requirement to bond the armour of an swa cable armour when using a core as the cpc? Could we could terminate swa's with stuffing glands at both ends. Now who thinks that is correct practice, not many i suspect. What code would that be for an swa glanced like that?

Well I'll answer my own questions; the armour of an swa is mechanical protection and even if not used as the cpc requires bonding; the braid on a SY cable is a screen but I personally would bond it at one end and cover the other end with heat shrink and connect via a stuffing gland. What code for braid not bonded? I'm not sure, but certainly a C3 minimum for me but I would be wary of describing it as an exposed conductive part.
 04 April 2013 09:51 AM
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AJJewsbury

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If it really is an extraneous conductive part then it will need bonding not earthing. The problem is the poor quality of tray work.

I agree.

If a SWA is buried direct, 522.8.10 requires the SWA to be earthed to provide shock protection from mechanical damage. Likewise if you've opted to use SWA or other metal covered cables concealed in a walls or under floors, then 522.6.100 etc require it to be earthed. If you as the designer choose to use a class 1 wiring system as the conditions are such that class 2 systems (e.g. insulated & sheathed) wouldn't provide adequate protection in the circumstances (e.g. due to the likelihood of impact etc), the clearly the surrounding metal needs earthing to allow ADS to operate. But, if you're in a situation where say T&E would be acceptable and SWA/SY/CY was used for reasons other the protection from electric shock (perhaps there was some spare in the van), then I think it's going to be difficult to show that SWA cable with an unearthed armour is any more hazardous than T&E would have been.

I think there's a bit in GN 8 discussing plastic insulated+sheathed and metal sheathed cables on tray etc and concludes that in both cases the tray doesn't normally require earthing (although might require bonding if it is of itself an extraneous-conductive-part - e.g. passes through into another building).

- Andy.
 04 April 2013 08:47 PM
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leckie

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Well I think an armoured cable with the armour not bonded is a higher risk than a twin and earth cable due to the reason that the armour can become live with a penetration. And if you want to use armoured up because its in our van perhaps you should install it properly. Imagine you fitted a swa cable between two insulated enclosures and used brass glands with no tail from the banjo to an earth terminal. Cable gets penetrated and the armour is live. I wouldn't want to put my hand in one of the enclosures to carry out any work. Life would be much easier if we could gland swa cable with stuffing glands throughout but it would be a rubbish job. In my humble opinion.
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