p.f.c

[s.keech]

hi have started to do some testing but I am stuck on p.f.c and p.s.c.c test. have looked at gn3 and that is not clear with no illustrations and brian scadden book and also kitcher youtube video. Has the main switch got to be off for both of these tests and test on incoming L-N for p.s.c.c and L-E for p.f.c also should the main earth be connected as I know it should not be for ze. Thanks for any help.

 

[telectrix]

main switch off. test as you say with earthing and bonding connected. if it's PME then pscc and pefc will be the same.

 

[dazza1981]

IN a nut shell your exactly right mate, do your ze then re connect your main earth and do your pscc and pfc. Highest value of the both is recorded

 

[MDJ]

lol haha, just kidding chin up

 

[NickD]

test on incoming L-N for p.s.c.c and L-E for p.f.c

In principle that's right but it may be worth checking the relevant bit of the manual for your tester. On mine, regardless of which of the two tests you're doing, it says put L probe to L, N probe to N and E probe to E. Then select either loop or line test mode on the functions dial and test.

 

[telectrix]

In principle that's right but it may be worth checking the relevant bit of the manual for your tester. On mine, regardless of which of the two tests you're doing, it says put L probe to L, N probe to N and E probe to E. Then select either loop or line test mode on the functions dial and test.

is that a fluke? with the megger, it's a 2 lead job for Ze and pfc testing.

 

[Badged01]

is that a fluke?

Yes, but probably not in the sense your thinking of ....

 

[SirKit Breaker]

main switch off. test as you say with earthing and bonding connected. if it's PME then pscc and pefc will be the same.

There are 3 good reasons for doing it this way.

Firstly it is the correct method as Tel says.

Secondly you want the worse case scenario of Ze, i.e highest impedance on the supply to ensure your test result is that of the supply only, so no parallel paths.

Thirdly, you want the worse case scenario again, and the highest current measurement as possible PEFC/PSCC, so if your bonding and CPCs are not connected, then the result will be lower due to the lack of parallel paths, and so could lead to having unsuitably rated protective devices.

Cheers.............Howard

 

[NickD]

Yes, but probably not in the sense your thinking of ....

I don't have to stand for that...I'm going to sit down. Metrel.

 

[graham123]

If its TP double the reading remember

 

[Duncan Bennett]

is that a fluke? with the megger, it's a 2 lead job for Ze and pfc testing.

I love my Kewtech KT63. It uses 3 leads but N&E are connected.

 

[davesparks]

If its TP double the reading remember

eh? I haven't heard of this before, I was taught for three phase you measure PSCC phase - phase.

 

[NickD]

eh? I haven't heard of this before, I was taught for three phase you measure PSCC phase - phase.

Maybe that's what you do if you've got a meter that can do it, but if you don't it's acceptable to double worst-case single phase PFC (which is the method I was taught)?

 

[telectrix]

what he means is if your mft will not measure phase-phase, then measure phase-N and double the value ( should actually be x 1.732 ).

 

[davesparks]

If you're working on three phase why wouldn't you have a meter capable of testing three phase?