Quote:
Originally Posted by Ross Trician  Shakey would that mean then that if I installed a suitable spike etc at the incoming supply then I would have to ensure that all the instalations on the system (not just the 2 areas I have worked on) are correctly earthed and terminated etc throughout? and that they have adequate Ze, Zs, pfc tests etc?
What do you mean about the rcd wont work for the instalation?
( apologies for the many questions but it is helpfull when you get answers from someone who knows them) |
Ross, sorry, the RCD will work, but you should not use it
Look at 314.1 (got the 17th in front of me now, but its the same as in the 16th)
"every installation shall be diveided into circuits as necessary, to:
(i) avoid hazards and minimize inconvenience in the event of a fault
(iii) take account of danger that may arise from the failure of a single circuit such as a lighting circuit
(iv) reduce the possibility of unwanted tripping of RCD's due to excessive protective conductor currentd prodeuced by equipment in normal operation)
so for these three reasons, you cant use front end RCD's, unless they have lower value RCD's downstream, (like in a TT), but under the 17th, that will mostly go anyway
in answer to you first question, the Ze is ONLY at the origin, everythin else will be Zs - and yes, you take responsibility for the lot. The pint is, to certificate your work, as you know, you HAVE to include the supply characterisitics, Ze, PFC etc, which, unless you spike at the origin (or get PME installed etc) you wont have
sorry fella!