Metal Conduit (8-10inch) between PVC strip lights...... Another Bonding Question

[old_sparky_RE]

I have a building with row after row of light fittings where the containment between in 8-10 inches long metal conduit (20mm).
This metal conduit is between and incontact with the plastic body of the light fitting and protects the single core cables.

I have said the conduit does not require to be bonded.
Half the people who have become involved with this side with me half against.

I have proved the conduit is not connected or incontact to earth with an insulation test (result above 500meg) and so I say it does not require bonding.

Where is it in black and white where it says it does require it? Or better still where it doesn't need it !

With thanks

 

[malcolmsanford]

What cables are running inside this conduit

 

[Deleted member 9648]

It's not an extraneous conductive part therefore it does not require bonding.
It is an exposed conductive part and therefore it requires earthing....411.3.1.1
See definitions of the above in part 2 of 7671.

 

[malcolmsanford]

That is why I asked what cable is in it WP, if as likely it is singles then it will be an exposed conductive part and therefore need earthing

 

[Deleted member 9648]

Says single core in the OP Malc....:shades_smile:.....

 

[malcolmsanford]

I need to get to spec savers lol ...............:glasses2:

 

[tigerpaul]

As part of the wiring system it does require bonding.

 

[malcolmsanford]

It will need earthing Paul I agree, as I would consider it an exposed conductive part. I personally don't think it would be classed as an extraneous one and so not bonded

 

[tigerpaul]

Use SWA banjos to bond the conduits. Better still, convince the customer to have PVC conduits..

 

[Pockets]

Snag 24 of snags and solutions 4th edition says where unsheathed cables the conduit needs to be effctively earthed. However if sheathed cables are used it may not be necessary to earth the conduit.

 

[Engineer54]

As others have stated these short conduit lengths don't need bonding, they need ''earthing!! I take it that these short conduit lengths, (and they do seem very short) are individual conduits connecting the plastic light fittings via couplings and male bushes, and it seems you have scores of them...lol!! Well, it will at least keep you busy either fitting earthing nuts or banjo arrangements and linking them all out with a CPC!! ...lol!!!

Who was the idiot that purchased Plastic body lighting fittings with a metal conduit containment system in place.

 

[Guest55]

personally i think swopping out such short legnths of conduit with plastic will be quicker and neater than faffing about with banjos and wire links.

 

[Engineer54]

personally i think swopping out such short legnths of conduit with plastic will be quicker and neater than faffing about with banjos and wire links.

Half a dozen of one and 6 of the other, i reckon!! lol!!

 

[old_sparky_RE]

Apologies for not posting earlier but some reason thesite keeps throwing me out !!!!
Help for Heroes is now 20pound better off.
Best to be sure than to blindly plough on being wrong!! And I was wrong.

Who decided plastic and metal…. no idea! Properly down towhat was left in the bin after another job/jobs. CE fitting with UL metal pipebetween them.

UL fitting (inch) forced in to CE kit, 120v 60hz socketsrunning 230v 50hz, 120v breakers on 230v. Single phase UL boards 120v on 400v.It’s a never ending job but the pay is good.

 

[Engineer54]

Ahhh, your in Afghanistan then ...lol!!

I was on a project once, trying to utilise Yank conduit into UK back boxes it doesn't work does it!! lol!! , The Yank conduit soon got thrown out and metric bought in!!!

I take it, ...it is the crappy light gauge conduit that's been used, the one where connections between couplings and end fittings are by means of set screw, similar to our old slip 1/2'' conduit. Well if your now going to earth all these short bits of pipe, at least the Yanks have earthing nuts to fit those end fittings...lol!!!

 

[old_sparky_RE]

Split wedges I think they're called ! Undo the locking nut and slide this spade behind the locking nut and tighten, carry onseveral 100 times !!!!!!!

The conduit made from reclaimed Indian take awaycontainers, be nice if we could go 100% CE (UK) but the people who buy the kit get a percentage on every $ they save.

CE is more expensive and ALL the company's try to 'buy USA first' as they get money back from the Government and it shows they are true patriots and so they will get the next billon $ contract!!

 

[old_sparky_RE]

Again why am I only allowed to post in the morning I try answering all through the day and the web page just kicks me out???

 

[jeremy]

As a fix for this situation would it be possible to "sheath" the singles with some split 16mm plastic flexible conduit, negating the need to dismantle any of the installation apart from removing the covers and load trays of 1/2 the fittings?

 

[PRR]

> ...protects the...cables. ...the conduit is not connected or incontact to earth with an insulation test (result above 500meg) and so I say it does not require bonding.

The conduit is for protection? Try it. Smash it with a filing cabinet or over-enthusiastic ladder. Now Meg it. If you bash it hard enough, the wire insulation is smooshed, and now live wires touch the conduit.

If conduit is PVC, no shock will result.

If conduit is metal, the exposed metal is now a shock hazard. And very unexpected for the next guy who leans an aluminum ladder up there and steps-off from damp concrete floor.

If conduit is metal AND appropriately bonded back to the designated Earth and service common, the first bash will cause a short which will blow a fuse, making the wires dead/safe and forcing cautious investigation.

In general "ALL" touchable metal around the place "should" bond to electric common.

Even metal siding: there was a case of a nail through aluminum siding into a live wire. Nobody noticed until a painter was zapped off his ladder (actually the owners noticed a tingle but did nothing). If the siding had been bonded, that nail would have darkened some circuit and forced investigation. (If the coincidence were not noted this could be a very tedious job.) I admit I never see a bond on siding. Or metal roofing unless good lightning protection has been done.

That's general principles of decent wiring.

I'm not not an expert in fine points of the rules. Wirepuller posted chapter&verse "exposed conductive part ....411.3.1.1". It's exposed, it conducts, your first thought should be "bond it!"

Local custom and interpretation will vary. If it is a HIGH ceiling and very unlikely to get bashed hard enough to damage insulation through conduit, maybe bonding can be omitted. If the internal cable is rated rugged to withstand great abuse (what Malcolm asked and Pockets Snag-ed), perhaps bonding can be omitted. There's a new residential garage on my street 3 meters high inside, and I know our local inspector will not climb that high to check.

And if you are in Afghanistan then the occupants may face dangers worse than some live pipe on a ceiling. Of course we hope and pray that the odd blown fuse is the worst that ever happens in future.

> "sheath" the singles with some split 16mm plastic flexible conduit

I would say: if the conduit "can" be bashed hard enough to smoosh the cable insulation, the flex-tube does not add enough extra protection to count for much. Obviously a local inspector might deem it good enough in a marginal case.