swa and seperate cpc problem

[warren brown]

Is it a requirement of 17th edition to run a seperate
Cpc with a 4core 3phase supply ? ?

 

[pepparz]

all 4 cores up to 95mm² are fine to use armourings as cpc.

 

[pepparz]

you could of course use;table D10a in Guidance note 1: selection and erection BS7671:2008
to confirm this.

 

[Engineer54]

all 4 cores up to 95mm² are fine to use armourings as cpc.

So long as you're not using the wire armouring for bonding purposes as well as the circuits CPC, where it may not be of sufficient CSA (copper equivalent) to comply.....

 

[pepparz]

Hi engine 54, can u offer some evidence to support this?

 

[MDJ]

Is it a requirement of 17th edition to run a seperate
Cpc with a 4core 3phase supply ? ?

No .

 

[ChrisElectrical88]

Hi engine 54, can u offer some evidence to support this?

I would just take his word for it ;-)

 

[pepparz]

not doubting him id just like to read up on it.its a question i asked a couple of month ago on here.

 

[pepparz]

as far as i can see the CSA of SWA armourings upto 95mm² is larger than the associated line conductor so how can it not be suitable?

 

[MDJ]

as far as i can see the CSA of SWA armourings upto 95mm² is larger than the associated line conductor so how can it not be suitable?

have a read of 543, plenty of useful info in that area of the BGB

 

[Sintra]

I would just take his word for it ;-)

Or read GN8

 

[Sintra]

as far as i can see the CSA of SWA armourings upto 95mm² is larger than the associated line conductor so how can it not be suitable?

Might be a larger csa but you need to find out the Cu equivalent.

 

[old_sparky_RE]

Pep your right if you use 90 degree at 70 degree current carrying capacity levels!
90D at 70D is good up to240mm
90D at 90D fails at 16mm, 95mm and all above 150mm including 150mm.

THE ABOVE IS 4CORE - Table D10a and b refer of GN1 (Appendix B of GN 8 for more)

 

[pepparz]

sorry ive worded it wrong, should say-the csa of swa armourings upto 95mm² is larger than needed for the associated line conductor.ie > or equal to half size, and this includes copper. dont have the time to look through book at the mo so was looking to see if any one knows off hand.

 

[pepparz]

Pep your right if you use 90 degree at 70 degree current carrying capacity levels!
90D at 70D is good up to240mm
90D at 90D fails at 16mm, 95mm and all above 150mm including 150mm.

THE ABOVE IS 4CORE - Table D10a and b refer of GN1 (Appendix B of GN 8 for more)

why cant they put it in one book,i dont have gn8!