Am2 testing: Fault finding

[P666]

Hello everyone,

I have finished my 3 years at college and now have my AM2 tomorrow.

I have confident in the installation but need some help on a bit of the testing and fault finding.

We will be usin a megger tester.

How do I carry out PEFC and then PSSC on a three phase DB.

Also could do with some help in RCD testing.

And finally an insight has anyone sat the AM2 recently and what the fault finding consists of ?

And help will be much appreciated

Patrick

 

[JAWS]

This vid should help with one of your questions. As for the AM2 there is a great thread by sparkychick on the forum.

 

[P666]

Perfect cheersonly question is ... i thought you test PEFC and PSSC was at the main switch.

Is this wrong as he seems to be testing individual circuits?

Cheers

 

[Pete999]

Hello everyone,

I have finished my 3 years at college and now have my AM2 tomorrow.

I have confident in the installation but need some help on a bit of the testing and fault finding.

We will be usin a megger tester.

How do I carry out PEFC and then PSSC on a three phase DB.

Also could do with some help in RCD testing.

And finally an insight has anyone sat the AM2 recently and what the fault finding consists of ?

And help will be much appreciated

Patrick

 

[TJ Anderson]

Perfect cheersonly question is ... i thought you test PEFC and PSSC was at the main switch.

Is this wrong as he seems to be testing individual circuits?

Cheers

Genuinely, Im surprised after 3 years at college you don't know this. Not a dig at you, It's the colleges fault

Ze and Zs are both PEFC measurements but taken at different parts of installation.

 

[SparkyChick]

The fault finding is basically 7 faults in 2 hours. For each one you have to state the fault, it's location and the proposed fix (which must include 'and retest' as the last step).

Read the fault, pick appropriate test gear and set about finding it.

 

[Joshhosk]

This has confused me a little bit, on the am2 im sure you only do PFC on the main switch?

 

[gazdkw82]

It's got to be a PFC on the main switch only?

 

[Grant1987]

Genuinely, Im surprised after 3 years at college you don't know this. Not a dig at you, It's the colleges fault

Ze and Zs are both PEFC measurements but taken at different parts of installation.

You’ve confused and belittled newcomers here, colleges do a great job in trying to educate future sparkys. You’re Ze is your main earth fault loop impedance which In simple terms is your main earth, and the fault path back to sub station. Closer the substation the lower the Ze if you’re carrying out this test next to substation don’t be surprised by an extremely low reading but remember you’re maximum values inspector will ask this for each earthing system
[automerge]1569884464[/automerge]

You’ve confused and belittled newcomers here, colleges do a great job in trying to educate future sparkys. You’re Ze is your main earth fault loop impedance which In simple terms is your main earth, and the fault path back to sub station. Closer the substation the lower the Ze if you’re carrying out this test next to substation don’t be surprised by an extremely low reading but remember you’re maximum values inspector will ask this for each earthing system

External I should say ?

 

[TJ Anderson]

You’ve confused and belittled newcomers here, colleges do a great job in trying to educate future sparkys. You’re Ze is your main earth fault loop impedance which In simple terms is your main earth, and the fault path back to sub station. Closer the substation the lower the Ze if you’re carrying out this test next to substation don’t be surprised by an extremely low reading but remember you’re maximum values inspector will ask this for each earthing system
[automerge]1569884464[/automerge]

External I should say ?

Yes, most colleges do I'm sure.

No such thing as a main earth. That could be confusing for someone.

The conductor from the DNO earthing terminal to the main earthing terminal is the earthing conductor.

Ze is the Earth Fault Loop impedance measured at the origin of the installation.

 

[gazdkw82]

Yes, most colleges do I'm sure.

No such thing as a main earth. That could be confusing for someone.

The conductor from the DNO earthing terminal to the main earthing terminal is the earthing conductor.

Ze is the Earth Fault Loop impedance measured at the origin of the installation.

It's a strange one because everyone at college referred to the earthing conductor as either "main earthing conductor" or the "main earth"

Even the teachers used those terms. It's only when I did the 18th that I realised its called the "earthing conductor"

 

[TJ Anderson]

It's a strange one because everyone at college referred to the earthing conductor as either "main earthing conductor" or the "main earth"

Even the teachers used those terms. It's only when I did the 18th that I realised its called the "earthing conductor"

Yeah, I know mate. Loads of people do incorrectly call them that.

Same as people who talk about "earth bonding conductors". I heard a QS actually say that lol

 

[Grant1987]

Yes, most colleges do I'm sure.

No such thing as a main earth. That could be confusing for someone.

The conductor from the DNO earthing terminal to the main earthing terminal is the earthing conductor.

Ze is the Earth Fault Loop impedance measured at the origin of the installation.

Haha yes my terminology is a bit slack but try to simplify it as much as possible same as a lamp is a bulb to me and that’s my lingo with my customers, I’m not to the book with regards of my terminology but practically is where I believe apprentices, trainees learn most on site experience you can’t beat. I feel you just need to simplify it all. I understand the correct and proper terminology which is required for you to pass your college exams but I’m old/new school. Also you failed to mention the word (External) in your “Ze is the Earth Fault Loop impedance” ?
Source URL: Am2 testing: Fault finding - https://www.electriciansforums.net/threads/am2-testing-fault-finding.172516/#post-1579650

 

[TJ Anderson]

Haha yes my terminology is a bit slack but try to simplify it as much as possible same as a lamp is a bulb to me and that’s my lingo with my customers, I’m not to the book with regards of my terminology but practically is where I believe apprentices, trainees learn most on site experience you can’t beat. I feel you just need to simplify it all. I understand the correct and proper terminology which is required for you to pass your college exams but I’m old/new school. Also you failed to mention the word (External) in your “Ze is the Earth Fault Loop impedance” ?
Source URL: Am2 testing: Fault finding - https://www.electriciansforums.net/threads/am2-testing-fault-finding.172516/#post-1579650

I wasn't criticising you so I apologise if you feel that. If you are not "To the book" as you say, with terminology, then that is just something you can work on. I agree, practicality is important, but practicality and correct terminology is even better. We are all learning all the time.

Also, regarding Ze, I stated it is measured at the origin of the installation. This is, by definition, measuring the earth fault loop impedance upstream of that point e.g. external to the installation. Hope that helps.

 

[Grant1987]

I wasn't criticising you so I apologise if you feel that. If you are not "To the book" as you say, with terminology, then that is just something you can work on. I agree, practicality is important, but practicality and correct terminology is even better. We are all learning all the time.

Also, regarding Ze, I stated it is measured at the origin of the installation. This is, by definition, measuring the earth fault loop impedance upstream of that point e.g. external to the installation. Hope that helps.

It’s fine and no need to apologise we are all entitled to say what we wish (within reason) I’ve been critiqued a few times on here because my wording is not the best to put it mildly ?‍ but yes you’re right we never stop learning hence why I joined here to expand my knowledge and understanding and to give my opinion and advice but thanks anyway ?