Feeder pillar query

[mrloy99]

you should never rely on using the armoured wiring has a CPC.
specially 3 phase .

Hmmm

 

[mrloy99]

The Feeder Pillars I have worked on, relied on the sheath, be it SWA or some other armouring (not sure it was a long time ago) as the main earth conductor, you would need to look at SWA data to find out the CSA of the armour and then decide, if it's large enough in CSA to act as a Main Earth and a Bonding conductor, Atatched table is all the info I have, may help.

Thanks

 

[westward10]

Is the water pipe metal or plastic.

 

[mrloy99]

Is the water pipe metal or plastic.

Hi.The water pipe comes out of the ground in plasic then changes to copper after the stopcock then about 2 foot later terminates in a garden type tap...all inside the enclosure.
I suppose what I'm trying to figure out is if it is an extraneous conductive part..(dont think so.)is it exposed conductive part (doubt it)so then it doesnt require equipotential bonding..If it was copper coming out of the ground it would be different.(I don't know now if it even needs the 6mm)
The other item is the cabinet itself I suppose it could become live under fault conditions but should it need an additional bond in addition to the CPC?? I cant think why it would.
Thanks for your thoughts

 

[buzzlightyear]

Hi.The water pipe comes out of the ground in plasic then changes to copper after the stopcock then about 2 foot later terminates in a garden type tap...all inside the enclosure.
I suppose what I'm trying to figure out is if it is an extraneous conductive part..(dont think so.)is it exposed conductive part (doubt it)so then it doesnt require equipotential bonding..If it was copper coming out of the ground it would be different.(I don't know now if it even needs the 6mm)
The other item is the cabinet itself I suppose it could become live under fault conditions but should it need an additional bond in addition to the CPC?? I cant think why it would.
Thanks for your thoughts

you should never rely on using the armoured wiring has a CPC.
specially 3 phase .

 

[TJ Anderson]

you should never rely on using the armoured wiring has a CPC.
specially 3 phase .

More often than not CPC is the SWA sheath, particularly on TPN circuit. As long as the sheath CSA is considered and banjo'd with a fly lead to earth terminals in DB's and accessories then it is very acceptable.

 

[westward10]

Very much doubt it requires a main protective bond.

 

[Simonslimline]

you should never rely on using the armoured wiring has a CPC.
specially 3 phase .

Why not?

 

[buzzlightyear]

Why not?

if fault current that accrues on a system, if SWA is damaged at some point then it is dangerous then you are relying on the SWA to clear that fault .

 

[Simonslimline]

in any fault current that accrues on that system and if SWA is damaged at some point then it is dangerous then you are relying on the SWA to clear that fault .

If the cable is damaged then it is not fit for purpose anyway!

Using the SWA as the CPC is perfectly acceptable.

 

[buzzlightyear]

If the cable is damaged then it is not fit for purpose anyway

how would you know !

 

[Simonslimline]

how would you know !

So your reason for never using the armour as a CPC "especially if it is three phase!?" is, how would you know it is not damaged!

Suit yourself.

 

[cliffed]

This Q&A comes up all the time,regarding Swa as a cpc/main earth bond conductor.
The obvious answer Swa maybe ok for a cpc,but not for Mebc.
This situation is happening all over the place,installing Swa’s without regard for main Earthing/Mebc.
It’s how we get over it is the hardest part,especially if the installation is in service for years,without anyone reporting,it does not comply.
Who is actually gonna install another Mebc to the supply,how,who pays etc..can be a nightmare.

 

[buzzlightyear]

Q & A of the Day – Can the SWA of a cable be used as a CPC? - https://www.voltimum.co.uk/articles/q-day-can-swa-cable-be-used-cpc

 

[Simonslimline]

@Richard Burns, what did you dislike about post #23 out of interest?