The IET is carrying out some important updates between 17-30 April and all of our websites will be view only. For more information, read this Announcement

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 31 subscribers
  • Views 7399 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

RCD & cable mechanical protection

Apostolos
Good morning everyone.

I have couple of questions for the more experienced.

1) In order to get away from an RCD (assuming that the circuit does not feed a socket...) you need mechanical protection for cables chased in the wall at less than 50mm.

Does this mechanical protection need to be earthed as well if we assume that the cables will be protected by galvanized steel conduit???

Or just the steel conduit is enough?

2) I know that a SWA cable is considered mechanical protected by the SWA. Does the SWA need to be earthed? What if I use an external CPC and do not connect the SWA to earth. I guess this is the same question as question number #1...

3) I have a cable from PRYSMIAN called AFUMEX LSX BS8436 and in the description it states:

    "Independently assessed by ERA for nail penetration tests (1.5mm2 to 2.5mm2)"

     Does this make this cable mechanically protected like a SWA cable? Do I understand it correctly?

.....

Thanks for your time guys

Kind Regards

Apostolos
Parents
  • 0
    Armour, as in the sort of stuff which covers military hardware as opposed to the strands of SWA, which could easily be penetrated by any sharp pointy object, may not be tough enough to resist a nail gun, but let's consider the risk. Any contact between a nail and it's gun on the one hand, and a live conductor on the other is almost instantaneous. The nail is then usually buried beneath the surface, so casual contact is limited. In any event the damage has been done - it has not been prevented!


    I would like to think that a nail gun would be used by a tradesman who has some idea as to what lies beneath the surface. Now think of an old fashioned nail and hammer wielded by an ordinary person who has never given a moment's thought as to how the wires get to sockets. There is a very real risk of holding the nail whilst it makes contact with the live conductor. So simple mechanical protection may not only prevent a householder from getting a shock, it may also prevent significant damage to the building. I would not discount it in the domestic environment.

Reply
  • 0
    Armour, as in the sort of stuff which covers military hardware as opposed to the strands of SWA, which could easily be penetrated by any sharp pointy object, may not be tough enough to resist a nail gun, but let's consider the risk. Any contact between a nail and it's gun on the one hand, and a live conductor on the other is almost instantaneous. The nail is then usually buried beneath the surface, so casual contact is limited. In any event the damage has been done - it has not been prevented!


    I would like to think that a nail gun would be used by a tradesman who has some idea as to what lies beneath the surface. Now think of an old fashioned nail and hammer wielded by an ordinary person who has never given a moment's thought as to how the wires get to sockets. There is a very real risk of holding the nail whilst it makes contact with the live conductor. So simple mechanical protection may not only prevent a householder from getting a shock, it may also prevent significant damage to the building. I would not discount it in the domestic environment.

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