Testing ze at the origin

[joel89]

Hi all I'm an industrial sparky on maintenance doing my eal initial verification exam tomorrow was just wondering when doing ZE at the origin, do you do Neutral L1,L2,L3 and then Earth L1,L2,L3 and N+E ? Or is there between phases too? And is this the same for The PFC?

 

[nickblake]

Earth L1,L2, L3 and put the highest reading down and should be done with the power switched off and the main earth disconnected to eliminate parellel
earth paths

 

[joel89]

Thanks Nick. Just for the ZE this yes? What about the PFC.? So I'll drop croc clip on earth incomer after disconnection and goes across phases yes?

 

[Leesparkykent]

What tester are you using? Some testers require you to use the 3rd lead.

 

[ian.settle1]

Bit late to ask now isn't it?

 

[joel89]

It' begins with an M can't think off top of my head it's not megger, it's what the training centre borrowed us, it's on a domestic rig im involved with control panels mainly on the industrial side. Do a bit of installation work just never really done testing since college 7years ago!

 

[joel89]

Bit late to ask now isn't it?

I've done a bit on the rig the lecturer is a bit useless so I'm just writing down the test sequence and procedure just memorising for the morning

 

[joel89]

It's metrel multifunction tester jus come to me

 

[Leesparkykent]

It's metrel multifunction tester jus come to me

this one?

 

[joel89]

This one on this link

Metrel MI3000 Easi Plus 17th Edition Multifunction Tester

 

[newtothis]

Ole !
I've been getting to do ZE tests. :stooge_curly:
Using a megger has a 2 lead option and it gives you the Prospective Fault Current (PFC) at the same time.

 

[Andy78]

Ole !
I've been getting to do ZE tests. :stooge_curly:
Using a megger has a 2 lead option and it gives you the Prospective Fault Current (PFC) at the same time.

You might want to rethink using a PEFC value gained during the Ze test.

 

[Simonslimline]

Your PFC is going to be the highest Line to Neutral reading multiplied by 1.732, or doubled to be on the "safe side".

 

[Pete999]

Hi all I'm an industrial sparky on maintenance doing my eal initial verification exam tomorrow was just wondering when doing ZE at the origin, do you do Neutral L1,L2,L3 and then Earth L1,L2,L3 and N+E ? Or is there between phases too? And is this the same for The PFC?

https://www.youtube.com/watch?v=PUTn3t65na4

 

[newtothis]

Sorry - the question is about 3 phase.
Running for the hills

 

[Andy78]

Your PFC is going to be the highest Line to Neutral reading multiplied by 1.732, or doubled to be on the "safe side".

Or measured directly line-line.

 

[Simonslimline]

Or measured directly line-line.

Yeah as long as the tester is suitable to measure across Lines.

 

[Andy78]

Yeah as long as the tester is suitable to measure across Lines.

The OP's certainly is.

 

[GB.Kayak]

You might want to rethink using a PEFC value gained during the Ze test.

Why would you want to rethink? Are you referring to the fact that the fault current under short-circuit conditions in a 3-ph system is significantly higher than the line-earth fault current?

 

[spark 68]

Why would you want to rethink? Are you referring to the fact that the fault current under short-circuit conditions in a 3-ph system is significantly higher than the line-earth fault current?

No mate, it is because PEFC is taken with all bonding conductors and CPCs connected, Ze is taken with the Earthing conductor disconnected from the rest and measured on it's own.

PSSC is a different measurement.