urgent help needed with entries in the schedule of test result

[jem135]

I am doing the practical part of the Part P limited scope tomorrow. I know how to do all of the tests but how you find the PFC value in kA that is entered just below the Ze value
Also the short-circuit capacity value in the 2nd column just under over current Device.
Any ideas???

 

[telectrix]

measure the pfc at source after you've measured Ze, reconnect the main earth and test PFC. s/c capacity is listed in brb for the various types of DNO fuses.

you should find that your pfc =230/Ze approx.

 

[brucelee]

HI mate
from measuring the PEFC ( prospective earth fault current )by measuring between line terminal of the supply side of main isolator and the MET at the origin with theMain earthing conductor connected , and the PSCC (prospective short circuit current) at origin between the line terminal and the neutral terminal of the main isolator with the load removed ie all CBs switched off and the main isolator switched off and isolated, the highest of the two is the PFC and should be recorded on the eic under nature of supply parameters and the schedule of test results

the short circuit capacity of the device to be recorded in kA is the maximum the CB can withstand Icn before the CB is unusable and Ics is the service short cicuit capacity which in the case of a BS60898 is the same but not in all cases. The pfc should be less than or equal to the max breaking capacity of the protective device ie for BS 60898 type B 6kA usually for domestic but could be anywhere between 1.5kA and 25kA its marked on the front of the cb or the side of it

 

[jem135]

thanks for responding so quickly how do I measure the pfc? also as i only have access the o s guide I looked in there for the s/c capacity page 57 table 7.4 which seemed to agree with 1 example given on page 156 but not with the others.

 

[brucelee]

Hi mate to measure pfc you will need a prospective fault current tester which sometimes is part of a multifunctional tester
depends on the type of meter mate a megger you can use two leads a fluke you will use all three
its all in OSG,BS7671 or GN3 another good book is cristopher kitchers guide to inspection and testing
there are some videos i think on you tube type in google then look as all the tests are on there i think there is a link on here somewhere have they not taught you this on your course a pfc test as telectrix says is the same as a ZE only with pfc the main earthing conductor has to be connected

 

[brucelee]

YouTube - Chris Kitcher - Electrical Testing
here is the link

 

[Paul.M]

Look on YouTube for "electrical testing UK" and you will find what your looking for. Sorry I can't do a link atm (too many Stella's). Good luck for your exam tomorrow.

 

[Paul.M]

YouTube - Chris Kitcher - Electrical Testing
here is the link

Smart arse

 

[jem135]

thanks You have jogged my memory a little am I right in thinking you measure the pfc by running a loop l-n psc ( I will be using a metrel muli function tester

 

[brucelee]

just remember looking at it myself lol

 

[jem135]

thank all you have been very helpful I now feel fairly confident about the test tomorrow.

 

[brucelee]

Just hit the thanks button mate as thats enough to show your gratitude cheers glad i could be of help as others have helped me