Online assistance for electrical trade people in New Zealand and Australia Login  |  Register  |   Forgot Password
Assistance for electrical trade people
 

 

 

 


Click here to send Ron a pdf document for publication on this Topic

Documents must be less than 200k in pdf format

Posted By Topic: tre-foiling

benben
Apr 05 2019 16:09

Hey guys, looking at tre foiling triple runs of submains.
I have found information about this but none contains info on where the neutral and earth can be located.

Is there any reg that has more info on this.
Much appreciate the help.
   

pluto
Apr 05 2019 16:22

Ask the cable maker for this information and the effect it has on the maxium cable current rating.

There is some limited info in AS/NZS 3008.1.1.
   

ppaw1965
Apr 06 2019 00:34

From memory the N&E are ignored for calculating as if phases are all run at max N is no current. If there is current in the N means less current in some phases. E is only there to carry PSCC to operate protective device. Normally no current flow.
   

Sarmajor
Apr 06 2019 00:57

Appendix D of AS/NZS3008 has limited information about this.
The notes say to position the N so as not to disturb the symmetry of the Trefoils. Best to run your N’s together on one side of the trefoil arrangements. Same for the earths.
   

OwenK
Apr 06 2019 20:05

https://www.nexans.co.nz/eservice/NewZealand-en_NZ/fileLibrary/Download_540238390/NewZealand/files/Section%20Two.pdf
About page 7, shows recommendations for phases in parallel. Ignores neutrals and earths