PFC Calcs

[Nicktric]

Hi I am confused with my readings for Pefc as my Ze is .09 which would give me 2.55Ka but when I test PFC on my meter I get 5.62Ka? Ze, Neutral and earth leads clipped on disconnected main earth, probe Line on Supply side?

Can I check I am doing this correctly;3 lead PEFC piggy back Neutral/Earth clip on MET test on supply side of RCD. Pscc Clip on MET earth lead probe Line and probe Neutral supply side RCD?
Thanks

 

[Amp David]

What meter are you using?

 

[IQ Electrical]

The Ze should be measured with bonding disconnected, PFC with bonding connected to get a worst case scenario, this normally means that measured PFC is higher than V/Ze.

 

[Nicktric]

The Ze should be measured with bonding disconnected, PFC with bonding connected to get a worst case scenario, this normally means that measured PFC is higher than V/Ze.

Thanks I did the test as you described so that must be the correct result.

 

[Nicktric]

What meter are you using?

Hi Amp, It's a Kewtech three lead no trip loop/PFC

 

[telectrix]

as IQ's post. parallel paths will give you a higher value when measured than you would expect from the Ze reading. out of interest, you could re measure Ze with all the bonding and earthing connected, then re calculate PFC. ( not for the records, just to prove a point )

 

[Amp David]

On many a job having the main bonds connected won't definitely give parallel paths.

 

[telectrix]

true, but if his measured pfc is a lot higher than calculated, must be so.

 

[Amp David]

Until he tries with it with and without main bonds connected he won't now for certain if its a faulty reading that's all I mean.

 

[soar]

HI, CAN SOMEONE HELP ME ON THE PROCESS FOR TESTING Ze,
Q: isolate the supply,disconnect the main earthing conducter (MET),put the earth lead on the disconnected earth and the neutral on the supply side,and the live and the supply side,then test, and record the value? (am using a fluke 1653b)