no PFC

[jimnobot]

Hi Folks, so doing some testing on an installation today and when i carried out the PFC test i was getting a reading of 11A? I tested and retested and kept getting the same result! So, the installation in question is a shed that has had a split load board installed (by someone else) which is feeding several circuits. this is turn is fed from a DB in the house. the DB in the house main earth seems to be a pipe and the guys who did the install said this needed to be rectified and they were going to contact the supplier about it. So they provided a temp earth in the form of an earth rod. earth fault loop test at db = 21.7 Ohms. Im getting earth fault loop tests for all my circuits come back fine, just this PFC coming back at 11A? any ideas? re-checked my tester on my board at home and got a perfectly good reading....any ideas?

 

[Sintra]

11A would seem fine by calculation for the PEFC that you have tested. The PFC that would be noted on the paperwork would be the highest reading between the PEFC and the PSCC. What you need to do in this scenario is do the test between L & N and record the result for PFC.

 

[i=p/u]

High Resistance low current 230/ 21=

 

[telectrix]

yep.your pefc will be V/Ze. if the Ze is high, the pefc will be low. too low for OCPDs to operate in fault conditions.

 

[ackbarthestar]

I would have thought it was better to give it the correct name
pfc = prospective fault current - (phase to earth)
psc = prospective short circuit or current - (phase to neutral or phase to phase)

 

[Andy78]

I would have thought it was better to give it the correct name
pefc = prospective earth fault current - (phase to earth)
pscc = prospective short circuit current - (phase to neutral or phase to phase)

pfc being the highest recorded prospective fault current

 

[telectrix]

nope. pefc is prspective fault current to earth. pscc is phase to N.

 

[telectrix]

beaten to it by the man from hull.

 

[Andy78]

Man from Hull with a hangover too.

 

[telectrix]

no sympathy here. you drink sh!t, you feel like sh!t.

 

[ackbarthestar]

I think we might all be wrong as defined in the BGB
Ipf = prospective fault current
Isc = short circuit current

BYB has deleted the Isc although this is in connection with 712.433 and refers to DC overload I think.
However, there maybe an error as the acronym 'Isc' no longer exists but a few pages back the definition does

 

[Andy78]

I'm blaming the Hobgoblin gold for being so easy drinking. And the Sneck lifter, and the Ruby mild, and the Guinness, and the assorted pale ales and bitters.

 

[telectrix]

all gone to hell in a handcart. regs. for regs. sake ( and making money). last sensible edition was 16th.

 

[telectrix]

I'm blaming the Hobgoblin gold for being so easy drinking. And the Sneck lifter, and the Ruby mild, and the Guinness, and the assorted pale ales and bitters.

it's the guiness that's done you. PIRA have got sneaky now that violence has been eliminated.

 

[ackbarthestar]

Good grief - you lot have been on the pop