SWA glanded in a plastic stuffing gland

Hi all, 

I’ve been trying to settle a difference of opinion and looking for advice. 
we have several supplies fed in SWA, they have all been glanded off with a CW gland into the DB. At the load end, the armouring has been taped up and a plastic stuffing gland has been used where it enters  metal EV Chargers, its been done deliberately to isolate the earth to the chargers. 
My colleague and I think this is poor practice and think an isolating gland should have been fitted or the armoured terminated into a plastic enclosure prior to entering the charger. the below regulations are what we believe are contravened. 

Regulation 134.1.1Good workmanship by competent persons or persons under their supervision and proper materials shall be used in the erection of the electrical installation.

regulation 526.8 Cores of sheathed cables from which the sheath has been removed and non-sheathed cables at the
termination of conduit, ducting or trunking shall be enclosed as required by Regulation 526.5.

Our colleagues think we are incorrect, yet have conceded that the use of a stuffing gland isn’t to manufacturers instructions and agree that the stuffing gland isn’t supporting the cable like a SWA glad would by clamping the armour.

what is everyone’s view on here? 

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  • I don't quite follow the 526.8 argument - aren't all the cores enclosed by the EV charger enclosure? 134.1.1 is, as ever, debatable and probably needs a reference to some recognised guidance to make it stick.

    I think the stuffing gland approach was suggested by some official guidance some time back for isolating TN c.p.c.s. Personally I don't particularly like the approach as it doesn't make it simple to test the continuity/Zs at the load end of the armour - which you really should do if the armour is being relied upon for ADS for the cable itself (e.g. if the cable is buried or run through an environment where damage is a risk - and if it's not why bother with SWA?). The cable itself should be supported conventionally (e.g. by cleats/P-clips) as required and not rely on the termination of the armour for support. The stuffing gland approach does have the advantage of enuring there are no exposed-conductive-parts of the supply TN system (e.g. the brass gland) within reach of the EV's earthing system.

    My preference would be for a brass gland into a plastic enclosure (perhaps the charge point itself, if the enclosure is insulating), covered with a PVC boot to prevent the gland being touched, with the secured in some way if needs be to make sure it can't slip or be accidentally moved to expose the gland. I wouldn't say that was the only option though.

    Some might suggest that the boot doesn't have any guaranteed insulting qualities and so if a brass gland is used it should itself be enclosed inside an insulating enclosure to make sure it's not exposed within reach of the EV's earthing system.

    Some propitiatory SWA glands have and insulting outer shell, which might be worth consideration for such cases. I have also seen pictures of metal SWA (ZEN?) glands with in-built isolation between armour and enclosure (but I can't say I've ever seen them offered for sale in wholesalers...). and the issue of metal parts of the two systems remaining within reach of each other might still persist even then.

       - Andy.

  • Hi AJ, 

    I’d be interested to see the official guidance that you mentioned.  
    my argument is similar to what you’ve posted, I think making it off into a insulated box would have been the best course of action, however I think in this case they didn’t like the aesthetic  of a box under the charger. 
    thr cables are run in ducting then onto tray, so are fixed to the tray. It most probably will never be an issue, but pulling a cable out of a stuffing gland is much easier than a made off SWA. 
    you can get these glands, problem is the price tag and availability.

  • I’d be interested to see the official guidance that you mentioned.

    My memory isn't what it used to be, but I'll try to dig it out...

    I think in this case they didn’t like the aesthetic  of a box under the charger. 

    Does the charger have a metallic enclosure then? The might suggest another problem ... how are they ensuring the double/reinforced insulation of the live conductors up to the RCD (or equivalent)?

       - Andy.

Reply
  • I’d be interested to see the official guidance that you mentioned.

    My memory isn't what it used to be, but I'll try to dig it out...

    I think in this case they didn’t like the aesthetic  of a box under the charger. 

    Does the charger have a metallic enclosure then? The might suggest another problem ... how are they ensuring the double/reinforced insulation of the live conductors up to the RCD (or equivalent)?

       - Andy.

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