Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 7 replies
  • Subscribers 32 subscribers
  • Views 5772 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Cable in Buried Conduit

Nick Smith
Hi folks

I'm having a bit of a discussion about what type of cable is suitable to be buried in ducts. My reading of the BS7671 is that only multicore armoured cable should be direct buried or buried in ducts based on Table 4A2 (p390) and the fact that there are no current ratings for installation method D for anything except multicore armoured.


But Table C1 of the on site guide states that twin and earth is "For use underground in conduits or pipes".


My actual problem is being asked to comment on a design where 1c XLPE/AWA cables have been direct buried and also H1Z2Z2 singles have been installed in underground ducts. The H1Z2Z2 data sheet states that it can be installed in ducts, but I am taking that to mean ducts that are not buried, so I am almost sure that this is not acceptable.


Any comments appreciated.


Thanks

Nick
Parents
  • 0
    OK, well look and see what is buried elsewhere. HV underground 1 core cable (modern red XLPE/AWA) is direct buried all over the place and works fine at 11kV AC.  Why the question about the Solar cable, I presume that a ground-mounted solar array might be this, but as these are usually large, the red HV cable would be more suited to the high current and voltage expected? The thin stuff used for domestics will not be rated at more than a few Amps, and I don't have the specification for the insulation type although it is probably polythene itself or cross-linked polythene (XLPE) which is an excellent insulator. I am sure it would survive in a flooded duct, whether ideal is a different question.
Reply
  • 0
    OK, well look and see what is buried elsewhere. HV underground 1 core cable (modern red XLPE/AWA) is direct buried all over the place and works fine at 11kV AC.  Why the question about the Solar cable, I presume that a ground-mounted solar array might be this, but as these are usually large, the red HV cable would be more suited to the high current and voltage expected? The thin stuff used for domestics will not be rated at more than a few Amps, and I don't have the specification for the insulation type although it is probably polythene itself or cross-linked polythene (XLPE) which is an excellent insulator. I am sure it would survive in a flooded duct, whether ideal is a different question.
Children
No Data

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines