glanding off swa and earthing

[panikman]

hi all I have a bit of a problem and need a bit of clarification. ive run an swa cable Under some brickwork in back garden and cliiped to wall, to a ip65 junction box using stuffing glands and internal earth as protection so 3 core swa L N E. now it has all been sleeved up correctly and a spark has checked it and condemed it for the following : it is not earthed.........
he stated that it needs to be earthed via the swa in case a spade goes through it as it provides mechanical protection.... I agree with the mech protection side which it has, as its swa but it has ELECTRICAL protection through the earthed 3rd core continous throughout to the consumer unit in the outdoor unit. please advise as i was told never to rely on swa for an earthing protection on its own.

please note using the stuffing glands provide the ip65 throughout via the ip65 jb.

Please advise.....As he said he wants to do the job properly and supply test certs.

 

[sparkydude]

Your sparks is completely correct. the armouring must be earthed at least at one end of a run as he stated , if you hit it with a spade there is no guarantee you would hit the earth core aswell as the live is there.

You need to replace the stuffing glands with appropriate CW glands which afford a degree of waterproofing and also i would recommend using Piranha earthing nuts to save having to drill the Ip rated enclosure.

Nick

 

[Risteard]

please advise as i was told never to rely on swa for an earthing protection on its own.

Why not? The armour in SWA is the cpc. In the majority of cases it is perfectly adequate.

Why do you think two-core SWA is identified for line and neutral and three-core SWA is in phase colours?

 

[dingbat]

522.8.10 "Except where installed in a conduit or duct which provides equivalent protection against mechanical damage, a cable buried in the ground shall incorporate an earthed metal armour or metal sheath or both, suitable for use as a protective conductor."

 

[panikman]

thanks for such quick replies.

so even if we have a seperate earthing conductor within the armoured cable at least one end needs to have armouring connected to earth and no stuffing glands should be used?

 

[Taylortwocities]

so even if we have a seperate earthing conductor within the armoured cable at least one end needs to have armouring connected to earth and no stuffing glands should be used?

Correct

 

[panikman]

can a jubillee clip be used where a gland cannot be used with a fly lead?

 

[Taylortwocities]

 

[sparkydude]

Nope, no way mate , it is not designed for the job and would cause stress on the cable possibly leading to a pressure fault developing. You can buy something called a constant velocity spring which you could use to obtain an earth which basically goes around the armouring and you clamp a conductor under it in contact with the armouring to obtain your earth.

Nick

 

[Spark123]

thanks for such quick replies.

so even if we have a seperate earthing conductor within the armoured cable at least one end needs to have armouring connected to earth and no stuffing glands should be used?

The supply end of the SWA should be earthed. As sparkydude said, use CW glands to terminate the cable properly at both ends.

 

[ban-all-sheds]

..now it has all been sleeved up correctly and a spark has checked it and condemed it for the following : it is not earthed.........
he stated that it needs to be earthed via the swa in case a spade goes through it as it provides mechanical protection.... As he said he wants to do the job properly and supply test certs.

Must make a note of this topic to quote next time we're trying to get across to someone the importance of having their electrician do the design work, provide the specs etc, and the dangers of presenting him with a fait accompli which he doesn't like.

can a jubillee clip be used where a gland cannot be used with a fly lead?

OOI, what have you got against proper glands?

 

[1john]

Perhaps running the cable was all that should have been done here, there is no need for the shrouding if it isn't going to be earthed, you are looking at a huge potentially leathal fault if that shrouding became live and someone cut through the insulation inadvertantly!