AM2 testing

[kingkai]

Hi everyone,

a few questions here

Ze: In the AM2 is it just a 2hi test between L1 - Earth, L2 - Earth and L3 - Earth. Then take the highest reading out the three? and while doing that take the PEFC reading at the same time? after reconnecting the Main earth would I record my test result on the test sheet then take the PSCC - Then which ever was highest out of the PEFC and PSCC use that for my PFC but double the answer?
Obviously when doing the Ze the board is isolated but when it comes to doing the PSCC do I re energise the board and then do the test? and do all breakers have to be on?

Also on the schedule of results there is a Zs at Db, I think I have confused myself on this. In the AM2 I'm guessing the board is simulating that it is the only board of the installation therefore will only need to do a Ze?
Is the Zs at Db for when you have another DB fed off another?

when polarity testing its just a simple voltage check between phases - do I check phase rotation while doing this as well ?
And do I have to do Phase rotation on the three phase equipment before the Zs?


many thanks

 

[Pete999]

Hi everyone,

a few questions here

Ze: In the AM2 is it just a 2hi test between L1 - Earth, L2 - Earth and L3 - Earth. Then take the highest reading out the three? and while doing that take the PEFC reading at the same time? after reconnecting the Main earth would I record my test result on the test sheet then take the PSCC - Then which ever was highest out of the PEFC and PSCC use that for my PFC but double the answer?
Obviously when doing the Ze the board is isolated but when it comes to doing the PSCC do I re energise the board and then do the test? and do all breakers have to be on?

Also on the schedule of results there is a Zs at Db, I think I have confused myself on this. In the AM2 I'm guessing the board is simulating that it is the only board of the installation therefore will only need to do a Ze?
Is the Zs at Db for when you have another DB fed off another?

when polarity testing its just a simple voltage check between phases - do I check phase rotation while doing this as well ?
And do I have to do Phase rotation on the three phase equipment before the Zs?


many thanks

Hasn't all this been explained to you by the Tutor during the course, if not I would ask for my money back.

 

[davesparks]

Zs at the DB is different to Ze even when there is only one DB.
When you measure Ze you are only measuring the efli via the means of earthing, whne you measure Zs you are measuring the efli of the means of earth plus any other parallel return path in the installation.

Think about what exactly is being measured for each test and it should become obvious what should or should not be connected for each test.

For PSCC check what the tester you are supplied with is capable of testing, you should be able to ask the assessor whether the tester is suitable for/capable of measuring directly the line to line loop impedance, if it isn't then you will have to calculate the value using the measured line to neutral value.

 

[kingkai]

Hasn't all this been explained to you by the Tutor during the course, if not I would ask for my money back.

I haven't paid a penny lol

Yes it has been explained by the tutor a long time ago, and I have not had any practical experience in doing these tests. A lot of the sites I work at I am not allowed to do any testing at all.

So can you tell me if any of what i said is correct because i believe it to be so?

thanks you

 

[kingkai]

Zs at the DB is different to Ze even when there is only one DB.
When you measure Ze you are only measuring the efli via the means of earthing, whne you measure Zs you are measuring the efli of the means of earth plus any other parallel return path in the installation.

Think about what exactly is being measured for each test and it should become obvious what should or should not be connected for each test.

For PSCC check what the tester you are supplied with is capable of testing, you should be able to ask the assessor whether the tester is suitable for/capable of measuring directly the line to line loop impedance, if it isn't then you will have to calculate the value using the measured line to neutral value.

Thank you for that mate nice one

 

[Pete999]

I haven't paid a penny lol

Yes it has been explained by the tutor a long time ago, and I have not had any practical experience in doing these tests. A lot of the sites I work at I am not allowed to do any testing at all.

So can you tell me if any of what i said is correct because i believe it to be so?

thanks you

Have you tried access to the Trainee area of this Forum? lots of info to be gained there, ask one of the Moderators for permission. Not having any experience with the AM2 mate and the methods they preach I can't be sure my answers would be commensurate with this course. May be "Westward10" could help with access.

 

[Deleted member 105166]

I haven't paid a penny lol

Yes it has been explained by the tutor a long time ago, and I have not had any practical experience in doing these tests. A lot of the sites I work at I am not allowed to do any testing at all.

So can you tell me if any of what i said is correct because i believe it to be so?

thanks you

You need to get some practical experience, watching and working alongside an electrician on a few jobs.

 

[Simonslimline]

PEFC is measured with the earthing conductor connected to the means of earthing. The reason it is disconnected when carrying out the Ze is so parallel paths are not included in the test. Are you doing the Am2 at Culham?

 

[kingkai]

PEFC is measured with the earthing conductor connected to the means of earthing. The reason it is disconnected when carrying out the Ze is so parallel paths are not included in the test. Are you doing the Am2 at Culham?

Great thank you for that. Yes doing the AM2 at Culham.

 

[davesparks]

PEFC is measured with the earthing conductor connected to the means of earthing. The reason it is disconnected when carrying out the Ze is so parallel paths are not included in the test. Are you doing the Am2 at Culham?

To be precise, the PEFC is measured with the installation connected to the means of earthing, not just the earthing conductor.
Most test links on earth bars disconnect the earthing conductor from the installation, not the earthing conductor from the means of earthing.

And to be even more pedantic the PEFC isn't measured, the loop impedance is measured and the PEFC is calculated from that.

 

[Toneyz]

Have you tried access to the Trainee area of this Forum? lots of info to be gained there, ask one of the Moderators for permission. Not having any experience with the AM2 mate and the methods they preach I can't be sure my answers would be commensurate with this course. May be "Westward10" could help with access.

Pete, you had some good youtube videos by Chris Karcher you maybe could repost these are very good for the O.P.
Kingkai you need to get some practical experience on testing

 

[Pete999]

Hi everyone,

a few questions here

Ze: In the AM2 is it just a 2hi test between L1 - Earth, L2 - Earth and L3 - Earth. Then take the highest reading out the three? and while doing that take the PEFC reading at the same time? after reconnecting the Main earth would I record my test result on the test sheet then take the PSCC - Then which ever was highest out of the PEFC and PSCC use that for my PFC but double the answer?
Obviously when doing the Ze the board is isolated but when it comes to doing the PSCC do I re energise the board and then do the test? and do all breakers have to be on?

Also on the schedule of results there is a Zs at Db, I think I have confused myself on this. In the AM2 I'm guessing the board is simulating that it is the only board of the installation therefore will only need to do a Ze?
Is the Zs at Db for when you have another DB fed off another?

when polarity testing its just a simple voltage check between phases - do I check phase rotation while doing this as well ?
And do I have to do Phase rotation on the three phase equipment before the Zs?


many thanks

Kingkai, you could always go to the internet and search Chris Kerchar videos, I'll post one up for you to sample

There are many more to choose from enjoy

 

[Simonslimline]

To be precise, the PEFC is measured with the installation connected to the means of earthing, not just the earthing conductor.
Most test links on earth bars disconnect the earthing conductor from the installation, not the earthing conductor from the means of earthing.

And to be even more pedantic the PEFC isn't measured, the loop impedance is measured and the PEFC is calculated from that.

My megger has loop and pfc setting. Glad you know better though as ever.

I could of worded my post better.

 

[Grant1987]

Hi everyone,

a few questions here

Ze: In the AM2 is it just a 2hi test between L1 - Earth, L2 - Earth and L3 - Earth. Then take the highest reading out the three? and while doing that take the PEFC reading at the same time? after reconnecting the Main earth would I record my test result on the test sheet then take the PSCC - Then which ever was highest out of the PEFC and PSCC use that for my PFC but double the answer?
Obviously when doing the Ze the board is isolated but when it comes to doing the PSCC do I re energise the board and then do the test? and do all breakers have to be on?

Also on the schedule of results there is a Zs at Db, I think I have confused myself on this. In the AM2 I'm guessing the board is simulating that it is the only board of the installation therefore will only need to do a Ze?
Is the Zs at Db for when you have another DB fed off another?

when polarity testing its just a simple voltage check between phases - do I check phase rotation while doing this as well ?
And do I have to do Phase rotation on the three phase equipment before the Zs?


many thanks

Hi mate sounds like you have good understanding of electrics and on right track don’t over complicate things and get yourself worked up. You measure you’re Ze and PFC at consumer unit with the main earth taken out of earth bar at DB put a crocodile clip on that earth and then put your neutral and live (line) conductor at main breaker with the probes on them as far as I’m aware that’s what the requirement is to measure you’re Ze and PFC on am2 although your tutor should guide you on right path you won’t have 3 phase as far as I’m aware on am2 bit risky for them to incorporate that

 

[davesparks]

My megger has loop and pfc setting. Glad you know better though as ever.

I could of worded my post better.

Yes it has the setting and displays the values, mine does too, but it doesn't measure the PFC, it calculates it from the measured loop impedance and voltage. This is made clear in the manual.

To actually measure the PFC you would have to allow that current to flow, and there's no way a meter is going to survive even a modest PFC flowing through it.