Ze and PSC

[doglog]

Today I have tested a new installation in a block of flats (ground floor). When I took a Ze reading the meter read 0.00.
I have taken this to be 0.01 as this is the lowest credible reading possible on my meter. When I tested PSC the meter read OL or out of range.
My question is can I use Ohms law to calculate the PSC and do I log the result as >'the result' or just 'the result'..
I know it sounds a bit fussy but we have an NICEIC inspection soon so need to be on the ball.
Thanks for your help.

 

[sparks1234]

So what breakers you gonna use on that then?

 

[electricAl]

So what breakers you gonna use on that then?

Big & expensive un`s methinks

Seriously, Dogleg, i wouldn`t `assume` its 0.01 - or anything else. Your name will be on that EIC saying you`ve checked compatability of Pfc arresting device against established max Pfc.

What are the breakers Icn rated? Whats the supply cable. Those values suggest you`ve got a good, clean earth if nothing else

I`d suggest you first check your meter on another install, or try another meter in the one you mentioned. If AOK you`re gonna have to establish what the max PSCC actually is someway or other. You could always try the DNO

 

[xraytek]

Dont know what meter you have, but with my Fluke 1651 you can toggle between 10KA & 50KA limit for EFLI by pressing the on/off button and F2 at the same time.

Default is 10KA so have never changed the setting, but wonder if it will allow readings to be taken instead of 'out of range'?

EDIT-

Was also wondering if by selecting 50KA on a Fluke, will it provide a more accurate result when testing supplies of >10KA?

 

[c.boy]

Today I have tested a new installation in a block of flats (ground floor). When I took a Ze reading the meter read 0.00.
I have taken this to be 0.01 as this is the lowest credible reading possible on my meter. When I tested PSC the meter read OL or out of range.
My question is can I use Ohms law to calculate the PSC and do I log the result as >'the result' or just 'the result'..
I know it sounds a bit fussy but we have an NICEIC inspection soon so need to be on the ball.
Thanks for your help.

As mentioned check your tester!!!! bats are gone a think!!!

your pfc is 230/ ze so 230/.01=23000 had high readings in top floor flats but never the bottom!!

 

[doglog]

yes got another loop tester on the board today and exactly the same..0.01 at the top of main switch also took reading at cut out with 16mm earth disconnected and the same..0.01!!
can get a very high Earth Fault reading (18KA) but no short circuit reading..out of range (>20KA)..
I think we will have to contact the supply company to sort this out..
Surely they shouldnt supply with this low Ze??
Do you know what are the highest rated 60898s or equivalent?
Thanks for your time

 

[c.boy]

yes got another loop tester on the board today and exactly the same..0.01 at the top of main switch also took reading at cut out with 16mm earth disconnected and the same..0.01!!
can get a very high Earth Fault reading (18KA) but no short circuit reading..out of range (>20KA)..
I think we will have to contact the supply company to sort this out..
Surely they shouldnt supply with this low Ze??
Do you know what are the highest rated 60898s or equivalent?
Thanks for your time

pfc live to neutral and if 3 lead tester earth onto neutral???

ze disconect main earth from main earth bar???

is another flat into your earth block seen this many times where the main earth jumps into another
flat!!!!

stupid ? is the supply earth tight???

 

[doglog]

yes all testing done correctly..3 lead tester black AND green to Neutral bar and red to top of main switch live..
Supply earth is tight..if it wasnt wouldnt Ze reading be higher and therefore Pfc be lower??