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 102 replies
  • Subscribers 31 subscribers
  • Views 7308 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

Shock Likelihood at Switch.

Zoomup
Mornin' All,


I have just inspected and tested a renovated  old flat's wiring. The original lighting wiring in places has no circuit protective conductor. The owner has installed metal plate light switches to two positions with wooden back boxes. At these two positions there is no circuit protective conductor. The flat has a new R.C.B.O. consumer unit and all other wiring is good.


I have recommended that the switches have a C.P.C. installed (difficult and disruptive) or be changed to all insulated types.


Just what is the shock risk at these two switch positions? What is the likelihood of the metal plates becoming live due to a fault? Has anyone every seen a metal plate switch break down so that the plates becomes live?


Thanks,


Z.

Parents
  • 0

    John Peckham:

    I would always code an un-earthed light fitting or metallic light switch as a Code 2 which would make an EICR "unsatisfactory ". That is my engineering judgement ...




    John, what about an ordinary ceiling rose and pendant? The lamp holder isn't earthed and unless the loop is at the rose, the CPC just stops in its terminal. The same goes for a non-metallic switch on a non-metallic box.


    I'd give them a C3, partly because a householder might (as appears to have been the case in the OP) change them for metal fittings.


    I agree that an unearthed metal fitting is a C2, RCD-protected or otherwise.

Reply
  • 0

    John Peckham:

    I would always code an un-earthed light fitting or metallic light switch as a Code 2 which would make an EICR "unsatisfactory ". That is my engineering judgement ...




    John, what about an ordinary ceiling rose and pendant? The lamp holder isn't earthed and unless the loop is at the rose, the CPC just stops in its terminal. The same goes for a non-metallic switch on a non-metallic box.


    I'd give them a C3, partly because a householder might (as appears to have been the case in the OP) change them for metal fittings.


    I agree that an unearthed metal fitting is a C2, RCD-protected or otherwise.

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