Discuss sub main started. in the UK Electrical Forum area at ElectriciansForums.net
SWA has a 3rd core for cpc as well as the gland earthing to the steel cab. why a banjo in a steel enclosure?
Because the steel you have drilled should not be relied on for an earthing solution(note in your set-up its a gland plate thus relies on self tappers as a fault path) the regs state a separate tail to be used, this is regardless of having a separate earth you still have to have an effective earthing of the SWA even if you have an additional core.
i see what you mean. i usually fit banjos and a tais as standard, just thought this job would not require, as armour is not used as cpc. paint has been removed,no need for rust prevention as it's in a dry environment. but will just bung in banjos and tails when back there wednesday. thanks for the heads up. been doing too much domestic lately.
OK ...i`m just going to come in at this point Dark..Because the steel you have drilled should not be relied on for an earthing solution(note in your set-up its a gland plate thus relies on self tappers as a fault path) the regs state a separate tail to be used, this is regardless of having a separate earth you still have to have an effective earthing of the SWA even if you have an additional core.
Consider yourself Dismissedi see what you mean. i usually fit banjos and a tais as standard, just thought this job would not require, as armour is not used as cpc. paint has been removed,no need for rust prevention as it's in a dry environment. but will just bung in banjos and tails when back there wednesday. thanks for the heads up. been doing too much domestic lately.
i see what you mean. i usually fit banjos and a tais as standard, just thought this job would not require, as armour is not used as cpc. paint has been removed,no need for rust prevention as it's in a dry environment. but will just bung in banjos and tails when back there wednesday. thanks for the heads up. been doing too much domestic lately.
This is why for the extra cost on these kind of installs, I bung in a length of 4" trunking, 2" bushed and earthed. Then I gland all my SWA's in, bolt through the banjo but no tail required.
R2 on each would confirm any chances of differing potentials appearing...Do you earth the armouring at both ends? I was told that you should because if you didnt and the unearthed end was terminated into an enclosure with other earths there could be a risk that they could be at a different potential.
OK ...i`m just going to come in at this point Dark..
Tel did mention about sticking a fly lead on them armoureds i glanded off into that panel....i said no...on the basis that its a steel enclosure....
so if theres any contravention here then i will stand and take fire for it....
no i know that.It was only brought up because its a gland plate Glen and not the main solid steel enclosure so would require a tail earth regardless of the separate core, don't get me wrong there was no intent to sound like I was taking a pot shot at his work but that aside I admire your honesty
not always needed, I could show you pictures of a place that has that much steel bonded to the MET its a waste of copper to put on fly leads to MB.Why fit a banjo when glanding onto galvanised trunking?
Personally I use earth nuts these days as they make good reliable contact whether it's bare metal or painted. I only connect a flylead with insulated enclosures or if I have any reason to doubt the earthing of the metal I'm glanding in to.
Gland plates I will run a flylead to the gland plate and sometimes replace it with a brass plate if I have a lot to make off to it.
not always needed, I could show you pictures of a place that has that much steel bonded to the MET its a waste of copper to put on fly leads to MB.
we are talking about unistrut from window brackets on steel girders bolted to floor.
we get through a fair bit of unistrut. at least 50 x 3m lengths in this one room
not always needed, I could show you pictures of a place that has that much steel bonded to the MET its a waste of copper to put on fly leads to MB.
we are talking about unistrut from window brackets on steel girders bolted to floor.
we get through a fair bit of unistrut. at least 50 x 3m lengths in this one room
just because its a waste doesn't mean I dont have to do it.You're talking to someone who would be more than happy to carry on the old method of building a steel frame from steel angle welded together to carry the switchgear and busbar etc then bolting the incoming earth to the steel frame and everything else earths through the steelwork/trunking etc.
I've just started subbing for a company who had me installing 19core SWA to carry 6 circuits, I'll be having words about that waste of copper soon enough, 12core would have been fine!
I've seen the materials list for the next job too, 700mts of G/Y to pull in to steel trunking/conduit! I'll be buggered if im wasting my time doing that!
new sub as existing 3phase board is full. this is the job that glenn's with me on. just got the first 3 single phase circuits in. waiting for location of 3 phase supply before getting cable in.
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Reply to sub main started. in the UK Electrical Forum area at ElectriciansForums.net
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