High PFC

[Guest123]

Hold on you said you did a PFC between Live and Neutral??? PFC is between Live and Earth You have measured a PSC which will be different on a TN S system. try it again on between Phase and Earth

Hang on chaps, we seem to be suffering from a difference in terminology.

PSCC = L-N fault current measurement
PEFC - L-E fault current measurement
PFC - is the highest of the two above readings noted on the test cert.

 

[scotsparky]

Lenny i just remember it as

PSC Prospectice shortcircuit current L-N
PFC Prospective Fault Current L-E

never used PESC

but agreed biggest on sheet.

 

[old dog]

Hang on chaps, we seem to be suffering from a difference in terminology.

PSCC = L-N fault current measurement
PEFC - L-E fault current measurement
PFC - is the highest of the two above readings noted on the test cert.

yes lenny me and GN3 make you right

 

[andyb]

Hold on you said you did a PFC between Live and Neutral??? PFC is between Live and Earth You have measured a PSC which will be different on a TN S system. try it again on between Phase and Earth

The maxium prospective fault current is the current that would flow in the event of a fault either between live & earth (maxium prospective earth fault currrent) or between live conductors (maximum prospective short circuit current), whichever is the greater.

 

[Notsosmart]

Had a quick look today, the L-N loop is .02 ohms, the supply voltage is 250v (another issue)

Andy,

You will measure 250v as this is the open circuit voltage across the sub-station windings esp as it sounds like you are sitting on the transformer! lol
It may be worth phoning the manufacturer of the CU; if they build to BSEN 60439-3 then this makes allowance up to 16k using 10k mcb's ~ speak to their tech dept. Remember IEE regs defer to manufacturers instructions.

I hope this is useful ;0)
Gaz.

 

[andyb]

Thanks Gaz,
if you look at my post of 3 weeks ago where you lifted my quote from you will see that I mention that.