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 3 replies
  • Subscribers 32 subscribers
  • Views 535 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

Swa cpc to motor

MrJack96
I’ve recently seen a motor wired directly from the local isolator to the motor terminal box in 3 core 1.5mm cable. The gland has been made off into a threaded hole in the motor terminal box and at the isolator end directly connected to the incoming swa from the MCC by means using a flylead. My question is is this a sufficient for earthing the motor. My understanding is you can use the armour as a cpc but wasn’t sure if any additional “fly leads” should be fitted at the motor end?  


thank you guys!
  • 0
    Threaded holes are usually perfectly good for earth continuity - that's how metal conduit is joined after all. Plain holes in thin walled steel enclosures can be tricker - it can be made to work but needs to be done carefully - e.g. making sure all paint etc is thoroughly removed and is properly tightened etc. so is seen as a bit riskier and so many prefer a banjo, ring crimp (or a proprietary earthing nut) and flylead to make sure in that situation. Doubly so where the cable is glanded onto a removable gland plate where you'd have a second (usually) painted junction (between plate and rest of the enclosure) to contend with too.

       - Andy.
  • 0
    Do not ignore any potential motor vibration or physical cable impact that may loosen the mechanical connections of the s.w.a. over a period of time. A loose c.p.c. connection is not good.


    Z.
  • 0
    Best to drill and tap a M5 or M6 hole and fit a brass nut/bolt arrangement to ensure good contact if one is not already provided, so long as IP integrity is not compromised by doing so.

Community Rules & Guidelines