Hi all.
Prospective Short Circut Curret.
Now , if you measure the impedance on a installation P to N , and get a reading of 0.21 OHMS , the max current flow between these two points P and N will be 230/0.21 = 1095A.....1KA.
Now if you have 3 phases , and each are the same impedance P to N ...
just done eicr on a 3 phase db LI= 1.33KA L2=1.44 L3=1.48 THESE ARE THE PSCC VALUES SO ADDED TOGETHER THEY GIVE ME 4.25 KA THE LAST TEST DONE 5 YEARS AGO WAS 5.5KA NO WHAT WOULD CAUSE THIS TO BE LOWER NOTHING HAS CHANGED IN DB AND I NO THE READINGS ARE ACCEPTABLE YOUR THOUGHTS PLEASE
Can some one explain if your pscc value is say 4.6ka well in gn3 it says that your protective device must not be less than that value so say the protective device was 5ka how would the protective device trip if it's fault current was only 4.6ka please explain cheers lads
After a little bit of advice please
We are doing our Dead and Live Testing at college tonight. I am ok on most of it but due to not having much time to practice our live testing I need a bt of advice.
Live Test:
CCU breaker off
Prove VID - Test for dead with VID - Re-prove
Ze - remove main...
Hi
I have just qualified as an electrician but am wanting to do my wiremans license and have been told to do some inspection and tests before doing the exam so that I can have a practical understanding of the system. With regards to this I did a PSCC test on a simple installation. Using a SUB...
I have my am 2 comin up and its on a 3 phase board (TNC-S) my question is when doing the live tests first i would do the Ze with the high current 23A setting (Megger LT7) between each phase and removed main earth (main switch off and on supply side) then work out Zs = Ze + (R1 + R2) and use...
I have just done a consumer unit change and on testing for Ze, PEFC and PSCC got the following results -
Ze - 2.20 (This is very high - what might be the problem and what can I do?)
Test with main earth disconnected L-PE 135 KA ( Very high ?)
Test with main earth connected L-PE 111...
:confused::confused:hi all testing new install warehouse units 2 of first unit Ze 0.09 PSCC 2.45 KA second unit Ze 0.01 pscc off the scale of 20 KA am i too close to sub station help lol
Hi all. Can someone please explain the difference between the two. Also if I know the Ze on a single phase installation is it a simple Ohm's law calculation to find out the Pscc?
Hi everyone
Im fairly new to electrics and the forum, im looking for some help on testing of a PME supply, It is my understanding that because the neutral and earth are combined the psc and pfc should measure the same. (as told by my assessor from Elecsa) I have a pfc of 3ka and a pscc of...
Just started back testing after 3mths install work,its easy to forget things after a break.On the last pir we did 3 phase pscc was noted on meter then this measure was doubled and put on test sheet(as it was 3 phase) Now starting on this job the guy in charge does not double this measurement...
Setting up a temp site board in a little brick bunker, DNO haven't supplied an earth as its an out house.
So I've installed a rod and am getting a Ze of 44.7 ohms.
Now my PEFC and my PSCC are both 5A's.
Why are they the same as its now TT? Should they be the same :confused:.
Should'nt the...
TNCS system am I mad went to a house today PME system PSCC and PEFC are supposed to be the same got 4.8kA at main switch and when I did the PEFC I got 7.1kA is this correct and if not what would cause it.
Thanks in advance.
Chris
Sorted just tried the same tests at home looks like my...
got a submain feeding a consumer unit, bit unsure with the pscc, pefc and pfc
pscc would be voltage / resistance of live and neutral cables plus the ze
pefc would be voltage / zs
how do i get pfc, is this just the highest of the 2 readings?
if i was fitting a 3 phase board pscc would it just...
i'm currently studying for the 2391 exam and have been asked on a mock exam paper to calculate the pfc and pscc of an installation. Its a 3phase system supplying circuits of 400/230v 50hz with a Ze value of 0.2ohms.
I know the calculation for pfc = V/Ze but how do you work out the pscc. Its my...
I am new to testing and im trying to learn all i can about each test.
Today i have been practicing my Ze tests, PSCC & PEFC.
Please can someone tell me if i am performing the tests the correct way and if my results look genuine?
(I have a feeling my results on this occasion are way out)
I...
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc