SWA cables - fly leading armour as cpc??

[snipersmith87]

Just after A bit of advice regarding a load of swa cables into dist board. What's people's preferred methods / good practice regarding banjos fly leads etc. Banjos inside?? If multiple cables are using armour as cpc is it considered bad practice to use 1 fly lead between the two Banjos??? Is it worth fly leading just to earth armour when not cpc or just rely on metal enclosure of db???? Got quite a few and want a tidy job

 

[Spoon]

There is nothing wrong with using the metal enclosure of the board. Also nothing wrong with using the armour as cpc, as long as it is suitable.

 

[snipersmith87]

Appreciate the reply spoon. I understand there's nothing wrong with using the armour as cpc. However when using armour as cpc is it considered good practice to fly lead. Testing purposes??? What about 2 banjos from separate cables with one fly lead???

 

[buzzlightyear]

1 fly lead between the two Banjos???

??????????????????????

 

[ipf]

Try these.......

 

[Leesparkykent]

If the armour is used as the CPC then you have no option other than to fly lead. I like the piranha nuts personally.

 

[Strima]

The fly lead must satisfy the adeabatic equation if using the armour as a CPC.

 

[Spud28]

As ipf's post much easier to use than banjos

 

[Spoon]

Appreciate the reply spoon. I understand there's nothing wrong with using the armour as cpc. However when using armour as cpc is it considered good practice to fly lead. Testing purposes??? What about 2 banjos from separate cables with one fly lead???

Something like this will be good.

 

[Pete999]

Appreciate the reply spoon. I understand there's nothing wrong with using the armour as cpc. However when using armour as cpc is it considered good practice to fly lead. Testing purposes??? What about 2 banjos from separate cables with one fly lead???

If you do that you will more than likely be cutting the csa of the cpc, two circuits sharing 1 cpc not good practice I would think, why not use PIRANHNA locknuts instead of banjos?
Piranhna Earth Nuts - Pirahna - https://www.tlc-direct.co.uk/Main_Index/Earthing_Index/Piranhna_Earth_Nuts/index.html
Much easier than flaffing about with Banjos IMHO

 

[Darkwood]

Using the enclosure alone without flyleads can be bad depending on the construct of the enclosure/board, if you are terminating to a removable gland plate of a any metal that is not a solid part of the construct then a fly lead is needed as you will be relying on the (usually) self tappers that affix the plate to the rest of the box and you cannot say for sure if these screw which are usually paint on paint contacts will carry a fault current.
(There is nothing wrong with looping fly leads as long as its CSA can serve the largest circuit.)
This is why you don't need a banjo on metal conduit through boxes because they are a complete solid mold yet most gland plates would require them to ensure good earth fault return.
I would also add that even when glanding to solid constructs then without a flylead you have to ensure good contact and not poor contact to paint, IE using robust serrated washers or removing the paint prior to termination.

 

[snipersmith87]

[QUOTE="buzzlightyear, post:
2 separate banjos sharing same nut and bolt. Drilling 1 hole.

 

[snipersmith87]

If you do that you will more than likely be cutting the csa of the cpc, two circuits sharing 1 cpc not good practice I would think, why not use PIRANA locknuts instead of banjos?
Piranhna Earth Nuts - Pirahna - https://www.tlc-direct.co.uk/Main_Index/Earthing_Index/Piranhna_Earth_Nuts/index.html

I thought it may be considered bad practice. Only thing confusing me is if we can use metal enclosure as satisfactory earth path through gland alone surely a fly lead regardless of it being 1 per 2 banjos is even better??? Another path to earth???

 

[Pete999]

I thought it may be considered bad practice. Only thing confusing me is if we can use metal enclosure as satisfactory earth path through gland alone surely a fly lead regardless of it being 1 per 2 banjos is even better??? Another path to earth???

Some of the SWA glanding jobs I have seen wont give much continuity to earth, nuts not tightened properly, enclsure not prepared correctly.

 

[snipersmith87]

See I've always seen fly leading any armoured at supply end cpc or not as best practice. However Ive came to wonder if im wasting time as I seem to be coming across more and more sparks who don't bother with it....... "It's connected to a metal board"

 

[Pete999]

See I've always seen fly leading any armoured at supply end cpc or not as best practice. However Ive came to wonder if im wasting time as I seem to be coming across more and more sparks who don't bother with it....... "It's connected to a metal board"

Yes but has the connection between the enclosure and the SWA been done correctly? they don't teach this sort of thing in the training outfits do they, make an end off job done.

 

[snipersmith87]

Using the enclosure alone without flyleads can be bad depending on the construct of the enclosure/board, if you are terminating to a removable gland plate of a any metal that is not a solid part of the construct then a fly lead is needed as you will be relying on the (usually) self tappers that affix the plate to the rest of the box and you cannot say for sure if these screw which are usually paint on paint contacts will carry a fault current.
(There is nothing wrong with looping fly leads as long as its CSA can serve the largest circuit.)
This is why you don't need a banjo on metal conduit through boxes because they are a complete solid mold yet most gland plates would require them to ensure good earth fault return.
I would also add that even when glanding to solid constructs then without a flylead you have to ensure good contact and not poor contact to paint, IE using robust serrated washers or removing the paint prior to termination.

Are you saying just loop between the banjos to earth bar darkwood??? Aslong as biggest cpc size??

 

[Darkwood]

Yes, if you think about it that is what the earth bar is itself, you're just bringing that setup forward to the glands. I do it often, it is a lot neater than having 10+ flyleads to have one and several neat loops, it also means you can double/triple etc the banjo's to one bolt hole allowing both neater appearance and more glands per given space.

 

[snipersmith87]

Yes, if you think about it that is what the earth bar is itself, you're just bringing that setup forward to the glands. I do it often, it is a lot neater than having 10+ flyleads to have one and several neat loops, it also means you can double/triple etc the banjo's to one bolt hole allowing both neater appearance and more glands per given space.

I think I'm gonna go with this idea. Be much neater. Do you only link to earth armours and then separate fly leads for each armour acting as the cpc??? This is what I was aiming for by using more than one banjo per bolt/link.

 

[Darkwood]

I think I'm gonna go with this idea. Be much neater. Do you only link to earth armours and then separate fly leads for each armour acting as the cpc??? This is what I was aiming for by using more than one banjo per bolt/link.

It makes no difference the fact is the armour requires earthing so its makes no difference if the SWA is the earth or just been earthed, the method I describe is normal practice as long as you size you cpc fly-lead correctly to the largest circuit if looping.

 

[westward10]

In the past where it was required to several cables I fitted a copper bar across the lot, down the side of the board to the earth bolt and a link to the earth bar.

 

[elsparko]

i always take 3/4 strands of steel into the cpc connection aswell, what if the gland gets loosened off and some doughnut doesnt put it back on correctly?

 

[Bobster]

i always take 3/4 strands of steel into the cpc connection aswell, what if the gland gets loosened off and some doughnut doesnt put it back on correctly?

How are you doing that and following manufacturers instructions in using the glands?

Also i'm reading that as 3 to 4 stands rather than 3 quarters. In which case, will do nothing anyway.

Aside from this, have you ever seen a properly terminated SWA gland just loosen on it's own?

If I saw this practice on one of my jobs I'm afraid I would insist on having it remade.

 

[Pete999]

i always take 3/4 strands of steel into the cpc connection aswell, what if the gland gets loosened off and some doughnut doesnt put it back on correctly?

How do you manage to do that elsparko? just curious

 

[elsparko]

easy, just dont cut through 3/4 of the strands of steel, bring them in through the gland, rest glanded as normal, i was taught to do this by a guy who done mainly industrial, i said if someone loosened it off and removed it , then reglanded it without the steel strands it would at least still have some connection to earth.

 

[elsparko]

and yes i mean 3 or 4 not 3 quarters! lol

 

[elsparko]

i should add that it still has a frying pan and flying lead, aswell as the 3 or 4 strands, and a dedicated cpc.

worst case scenario i still want there to be some earthing to the steel wire

 

[Pete999]

How are you doing that and following manufacturers instructions in using the glands?

Also i'm reading that as 3 to 4 stands rather than 3 quarters. In which case, will do nothing anyway.

Aside from this, have you ever seen a properly terminated SWA gland just loosen on it's own?

If I saw this practice on one of my jobs I'm afraid I would insist on having it remade.

Yes agree Bob, with respect "elsparko" not really something I would ever do. Don't think that would comply with the Regulations. On a par with snipping a few strands from a conductor to get in into the terminal. IMO.

 

[Bobster]

It's a poor way of doing it an unfortunately as you've now no longer got evenly applied pressure all the way round the gland seat, it's actually more likely to come loose with vibration.

It would compromise the IP rating of certain glands also.

 

[elsparko]

Yes agree Bob, with respect "elsparko" not really something I would ever do. Don't think that would comply with the Regulations.

just what i was taught to do, if its not right id rather be corrected than carry on doing it wrong, which regulation out of interest?, do you guys just gland the steel, frying pan either side of fitting, then drill through, bolt the 2 frying pans together, then flying lead from inner frying pan?

i do all the above, just taking in a few strands also, my first boss was insisted on these strands being taken into the cpc, incase someone removed the entire gland then put it back in just hanging there, there would still at least be some protection on the steel wire

we worked mainly on farms, so maybe industrial was the wrong word to use, but same kit, seen plenty of farmers have a go at reglanding and it just sits there hanging by the connections, gland about 3 inches from unit

but as i said if taking these 3 or 4 strands is wrong id rather not be wasting my time with it either lol

 

[elsparko]

It's a poor way of doing it an unfortunately as you've now no longer got evenly applied pressure all the way round the gland seat, it's actually more likely to come loose with vibration.

It would compromise the IP rating of certain glands also.

i dont do this on outside glands for this very reason, but standard glands its always been a force of habit, monkey see monkey do

 

[Bobster]

Sounds about right for a farm.

No you shouldn't be doing it, the glands aren't designed that way. As for a reg, I can't remember the number but it's something along the line of "suitable electrical and mechanical termination"

 

[Pete999]

Sounds about right for a farm.

No you shouldn't be doing it, the glands aren't designed that way. As for a reg, I can't remember the number but it's something along the line of "suitable electrical and mechanical termination"

Agree with Bob again, you have been taught the cowboy way I'm afraid, I would use PIRANHA locknuts as the locking ring for the gland an take a cpc from the connection on that locknut, beats having banjos or frying pans as you refer to them littering up the enclosure a far better and neater way of doing the job IMO.

 

[Darkwood]

@elsparko

I would stop this practice asap, regardless of who taught you this or what field of electrics they worked in, this is poor to bad practice, I would also question the quality of their working practices given they felt this was an acceptable method.
The glands are manufactured to certain tolerances and the SWA has to also be to similar tolerances so that the glands are more or less universal to the given size on their packets thus will fit what it says.

The glands rely on a full use of the strands to maintain an even grip all round, taking a number of strands away and routing them direct to the earth will give a poorer glanding termination and the remaining steel strands you have secured will not satisfy the reg's, under fault conditions the gland or strands brought through could fail and/or see damage done to the cable.

Your R1 + R2 tests and ELI do not show all issues and when 1000+ amps flow under fault conditions your gland needs to be good and solid thus should be fitted as per manufacturers instruction as the regs require you do.

If you secure and tighten your gland correctly it should not come loose, if due to environmental conditions you suspect the glands could loosen then serrated washes should be fitted, there is also the case that the installation requires regular inspection and this should pull up on any glanding issues.

In my experience of 30+ years I have never seen a gland come loose that was fitted correctly and suitably done to account for environmental conditions so I do not see this practice serves any purpose, the only glands I find loose etc are down to poor termination practices of which I would put your method as one.

 

[elsparko]

well i stand to be corrected and glad to have it pointed out, at the macallans site we used a really thick brass locknut that had screws on the side for terminating crimps to, nobody was bothered about me taking a few strands into the earth terminal aswell though

my first boss we only used what came in the gland pack

 

[elsparko]

i was

@elsparko

I would stop this practice asap, regardless of who taught you this or what field of electrics they worked in, this is poor to bad practice, I would also question the quality of their working practices given they felt this was an acceptable method.
The glands are manufactured to certain tolerances and the SWA has to also be to similar tolerances so that the glands are more or less universal to the given size on their packets thus will fit what it says.

The glands rely on a full use of the strands to maintain an even grip all round, taking a number of strands away and routing them direct to the earth will give a poorer glanding termination and the remaining steel strands you have secured will not satisfy the reg's, under fault conditions the gland or strands brought through could fail and/or see damage done to the cable.

Your R1 + R2 tests and ELI do not show all issues and when 1000+ amps flow under fault conditions your gland should be fitted as per manufacturers instruction as the regs require you do.

If you secure and tighten your gland correctly it should not come loose, if due to environmental conditions you suspect the glands could loosen then serrated washes should be fitted, there is also the case that the installation requires regular inspection and this should pull up on any glanding issues.

In my experience of 30+ years I have never seen a gland come loose that was fitted correctly and suitably done to account for environmental conditions so I do not see this practice serves any purpose, the only glands I find loose etc are down to poor termination practices of which I would put your method as one.

i wont be continuing doing it if its incorrect lol, and i never meant that the gland would just come loose, i mean that if some farmer did take it off and couldnt get it back on

i always checked my glands after fitting and none were ever loose, i feel like ive just been making any glanding ive done a harder job than it needs to be though

i dont do much industrial so thankfully not much will be affected, not sure about my old boss though! lol

 

[Pete999]

well i stand to be corrected and glad to have it pointed out, at the macallans site we used a really thick brass locknut that had screws on the side for terminating crimps to, nobody was bothered about me taking a few strands into the earth terminal aswell though

my first boss we only used what came in the gland pack

https://www.google.co.uk/search?q=p...x-b&gfe_rd=cr&dcr=0&ei=WNl5WrSMNamn8weSkoGIAQ
Here you go PIRANHNA nuts just the ticket for SWA why the gland makers don't utilise them in their gland packs I don't know

 

[elsparko]

ye

https://www.google.co.uk/search?q=p...x-b&gfe_rd=cr&dcr=0&ei=WNl5WrSMNamn8weSkoGIAQ
Here you go PIRANHNA nuts just the ticket for SWA why the gland makers don't utilise them in their gland packs I don't know

yeah thats the ones we used at macallans

 

[davesparks]

If the armour is used as the CPC then you have no option other than to fly lead. I like the piranha nuts personally.

If the gland is fitted to good clean metal or into a threaded hole such as a besa box then there’s no need to fit a banjo and flying lead.

 

[davesparks]

i should add that it still has a frying pan and flying lead, aswell as the 3 or 4 strands, and a dedicated cpc.

worst case scenario i still want there to be some earthing to the steel wire

You’re giving yourself a false sense of security there, the 3/4 strands will not add up to a suitable CSA to handle the fault current of the circuit. So if your scenario of a loose gland occurs then those few strands will show a suitable continuity reading on testing and go undetected, but under fault conditions will overheat and likely fail before the mcb/fuse operates.
This obviously leaves the armour and whatever else is connected to it live and very dangerous.