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29-03-2020, 23:29   #16
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I have never had a situation where it was impractical to earth both ends.
Suppose you had an SWA glanding into something plastic ? Yes you could put an SWA gland on it but if you tighten is as much as you should for a proper earth connection with the armor. The risk is you may strip the plastic threads or damage the plastic enclosure. So it defeats the purpose of the gland. Also in many cases the earth tag / banjo will not fit inside the enclosure (such as a commando socket) so it must be external which frequently won’t work.
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30-03-2020, 00:12   #17
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I agree, You will find alot of stuff in industrial and commercial work is made out of platic or fibreglass. One end of the S.W.A earthed is pretty common and acceptable.

In some case's you will see an external bango with a fly lead connected to a conduit or exposed conductive part.

Last edited by Tuco88; 30-03-2020 at 09:33.
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30-03-2020, 01:24   #18
 
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Prob doesn't matter here but afaik good practice is to gland at the supply side

I think I'm right in saying you could have problems with disconnection times on final circuits if the swa was glanded only at the far end

If the swa was then cut accidentally near the supply end
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30-03-2020, 09:13   #19
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Thanks all for quick responses. Would ESB have any issue with metal box inside the meter box considering the meter box has to be made of a non conductive material?
You won’t have room , esb meter ,esb isolater , tails protection and now your steel box 4x4 or 4x6
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30-03-2020, 09:17   #20
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Prob doesn't matter here but afaik good practice is to gland at the supply side

I think I'm right in saying you could have problems with disconnection times on final circuits if the swa was glanded only at the far end

If the swa was then cut accidentally near the supply end
If you only earth the swa at the meter side , don’t forget to run a cpc to earth the amour at the meter box
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30-03-2020, 09:27   #21
 
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If you only earth the swa at the meter side , don’t forget to run a cpc to earth the amour at the meter box
What other way is there of doing it, obviously you have to connect the swa at one end
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30-03-2020, 09:57   #22
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What other way is there of doing it, obviously you have to connect the swa at one end
I’ve seen some earthed from the neutralising link , that was my point , has to be from DB
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30-03-2020, 10:03   #23
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I think I'm right in saying you could have problems with disconnection times on final circuits if the swa was glanded only at the far end
As always the disconnection time will be a function of:
1) The earth fault loop impedance.
2) The rating and characteristics of the protective device.

When a disconnection time is calculated for a circuit within a steel conduit the CPC within the conduit used, not the conduit itself.
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30-03-2020, 11:19   #24
 
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I’ve seen some earthed from the neutralising link , that was my point , has to be from DB
Don't agree with that

If you have a metallic enclosure at the supply side you would need to earth the swa and enclosure from the supply side imo
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30-03-2020, 11:41   #25
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Don't agree with that

If you have a metallic enclosure at the supply side you would need to earth the swa and enclosure from the supply side imo
I’m not saying I’m right or you , this is what safe electric told me ,
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30-03-2020, 12:34   #26
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I’m not saying I’m right or you , this is what safe electric told me ,
They are not infallible. There should only be 1 neutralising conductor, and the swa should not be part of it imo. Anything earthed should be connected to the DB MET.
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30-03-2020, 13:08   #27
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If you only earth the swa at the meter side , don’t forget to run a cpc to earth the amour at the meter box
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Originally Posted by Jayzee. View Post
What other way is there of doing it, obviously you have to connect the swa at one end
Well if earthing at one end, running a long earth wire from the DB to the meter end would seem less intuitive than simply earthing the end at the DB.
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30-03-2020, 17:27   #28
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You won’t have room , esb meter ,esb isolater , tails protection and now your steel box 4x4 or 4x6

Agree the meter box is already fairly conjested.
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30-03-2020, 20:04   #29
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Well if earthing at one end, running a long earth wire from the DB to the meter end would seem less intuitive than simply earthing the end at the DB.
Agree would be somewhat impracticle to run an additional earth cable in parallel with the SWA from the meterbox back to the DB MET. I am leaning towards the suggestion of heat shrinking the armour in the meterbox (no metal box due to space restrictions) and just earthing at the DB end. Maybe it could be argued with Safe Electric that it is not reasonably possible to gland both ends. Extract from the Safe Electric December 2018 newsletter below.

Adequate electrical conductance shall be provided between metal sheaths or armouring of cables and the earthing terminals of equipment. This requires proper design. A proprietary gland is usually required. Please gland both ends of SWA cables (where possible).
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30-03-2020, 20:22   #30
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Maybe it could be argued with Safe Electric that it is not reasonably possible to gland both ends.
A better argument with Safe Electric is that you are in compliance with the rules. They can not force you to do anything that is not in the rules.

Quote:
Adequate electrical conductance shall be provided between metal sheaths or armouring of cables and the earthing terminals of equipment. This requires proper design. A proprietary gland is usually required. Please gland both ends of SWA cables (where possible).
......and glanding at the DB end with an SWA gland and earthing the armour there does exactly this.
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