Megger 1553 & PFC

[Trevor R]

Hi

In training at the moment just brought a Megger 1553 can anyone tell me how to connect to establish the PSCC at origin - I have done
the earth using 2 leads red - line \ green - earth and reading was 4.7Ka

When I then move the green to the neutral reading shows <1 A - what setting should the meter be on and how are the leads
connected - the detail with the meter states that 2 leads can be used

Thanks Trev

 

[mickys86]

I'm training too and I thought it was a three lead test...???

 

[telectrix]

it's a 2 lead test. have you got the leads correctly connected in the 1553? if the earething is TNC-S, the pssc and pefc should be the same.. readings taken with all earths and bonding connected, unlike Ze wher the main earth is dissed.

 

[i=p/u]

read the manual as some testers are different, if you dont have one maybe you can get off the megger.com site

 

[cyberjunction]

PFC – Prospective Fault Current


Made up of PSCC and PEFC


PSCC – prospective short circuit current
PEFC – prospective earth fault current (230v/Zs = PEFC)

• Change meter to PFC ( Hi ) ( LAST GREEN SETTING )
• Connect one probe to earth bar and one to line PEFC
• note reading
• Connect one probe to tail of Neutral & one to line (in) PSCC
• note reading
• Put Consumer Unit Cover Back On

The highest value should be of these 2 should be lower than mcb rating ie. 6000 or 10000 ;

 

[cyberjunction]

i use a megger 1553 and the above works for me, it was taken from notes I made BUT I AM A NEWBIE but I am sure someone will tell you/me if its wrong but i have been doing it this way since

 

[johnthesparky]

I may have this a bit wrong, and just flogged my 1553 to get the 1730.....

but IIRC early 1501s had 3 settings and the later 1501s and 1553s had 4 settings...

Ze and PFC low, which is a 3 lead test for RCD protected ccts
Ze and PFC high, which is a 2 lead, red and green test at 25A (?)

the test basically is live-earth then, live-neutral and record the highest value... should be the same for tnc-s

it sounds like your lead isn't connecting very well, I have found that megger leads sometimes don't work great when probing onto the screws on the main switch or breakers

 

[Amp David]

Hi

In training at the moment just brought a Megger 1553 can anyone tell me how to connect to establish the PSCC at origin - I have done
the earth using 2 leads red - line \ green - earth and reading was 4.7Ka

When I then move the green to the neutral reading shows <1 A - what setting should the meter be on and how are the leads
connected - the detail with the meter states that 2 leads can be used

Thanks Trev

You are measuring on the incoming side of the main switch when testing for PFC L-N. Done it myself in the past and had the same reading.