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 6 replies
  • Subscribers 33 subscribers
  • Views 1517 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Power cable for motors

Derek Eccles

I understand pump motors tend to be wired in delta fashion, not needing a neutral connection. I have seen cases where a 4 core SWA cable has been used to power the motor, the fourth core being used as the earth connection. Is it possible to get 4 core SWA cable with brown, black and grey colours for the phases and green/yellow for the earth or is it common practise to use the blue core as the earth ?

Parents
  • 0

    Whilst use of the armour as the CPC is allowed, it is in my view poor practice in the case of a stand alone motor*. I would prefer that one core of the supply cable be used in addition. In the absence of 3 phase and earth cable, I consider that marking the blue conductor in green/yellow is preferable to sole reliance on the armour.

    On many large contracts, the consulting engineer or architect will specify a copper earth conductor and prohibit sole reliance on armour.

    For a motor that is one of many mounted on steel work, or connected to metal pipes, I would be more tolerant of earthing via the armouring, since in practice there will be a reasonable fortuitous via the steel work or pipes. 

Reply
  • 0

    Whilst use of the armour as the CPC is allowed, it is in my view poor practice in the case of a stand alone motor*. I would prefer that one core of the supply cable be used in addition. In the absence of 3 phase and earth cable, I consider that marking the blue conductor in green/yellow is preferable to sole reliance on the armour.

    On many large contracts, the consulting engineer or architect will specify a copper earth conductor and prohibit sole reliance on armour.

    For a motor that is one of many mounted on steel work, or connected to metal pipes, I would be more tolerant of earthing via the armouring, since in practice there will be a reasonable fortuitous via the steel work or pipes. 

Children
No Data

Community Rules & Guidelines