Am2s advice

[gazdkw82]

I finally have my AM2s booked in November. I do feel a little nervous about it and iv started preparing. I finished college in March and need to brush up on things.

There are a few things I cant remember and hopefully someone will be able to help.

On the schedule of test results, so you list every phase results for the motor. So all results for L1, all results for L2 etc etc?

On the SWA, are the armourings used as a cpc? If not will they be looking to banjo and earth the supply side of the gland?

Iv never worked with data and so I'm unsure how you can test the cores for fault finding. Are they easily accessible?

For the distribution from the 3 phase board to the single phase, is that listed as 5s disconnection time?

 

[gazdkw82]

Anyone have any advice on this?

 

[Loki]

SWA
6mm 4 core - 3phs & N, steel wire armour to be used as cpc.

Data
Cat5 tester used. Leds light up in sequence on both parts of the tester. So both should light up in sequence the same ie 1,2,3, et

Ive signed up with xstraining on their AM2 Prep online course but it was £150 inc vat.
Very informative though

 

[Loki]

On the schedule of test results, so you list every phase results for the motor. So all results for L1, all results for L2 etc etc?


Ie like:
1L1
1L2
1L3

 

[gazdkw82]

Thanks Loki, that's really useful.

I have 2 days of training with my college prior to the assessment. Do you think i should do the xstraining am2 prep course as well?

 

[Loki]

I did it because im probably being a bit OCD lol. But mainly just to get a better understanding of what to expect.
I do get a prep day with Dcet who im doing my apprenticeship training with.

I always do loads of research & prepare as much as possible before doing any courses & exams etc.

 

[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.

Yeh I like to do the same Loki

 

[gazdkw82]

For anyone that has undertaken the AM2, was live polarity performed? Cant seem to find much information on it

 

[Loki]

For anyone that has undertaken the AM2, was live polarity performed? Cant seem to find much information on it

Its like testing 3phase safe isolation ie the 10 tests but live.

L1&L2 = 400v
L1&L3 = 400v
L2&L3 = 400v
E&L1 = 230v
E&L2 = 230v
E&L3 = 230v
N&L1 = 230v
N& L2 = 230v
N&L3 =230v
E&N = 0v

 

[gazdkw82]

Its like testing 3phase safe isolation ie the 10 tests but live.

L1&L2 = 400v
L1&L3 = 400v
L2&L3 = 400v
E&L1 = 230v
E&L2 = 230v
E&L3 = 230v
N&L1 = 230v
N& L2 = 230v
N&L3 =230v
E&N = 0v

Are you sure that's correct? Iv been told they will not let you test PFC between phases. Why would they allow you to measure between live phases on live polarity?

I thought it was just

L1-E =230
L2-E =230
L3-E =230

 

[telectrix]

Are you sure that's correct? Iv been told they will not let you test PFC between phases. Why would they allow you to measure between live phases on live polarity?

I thought it was just

L1-E =230
L2-E =230
L3-E =230

you're not testing pfc. you are testing to ensure that all line - line voltages are 400V (415 in real world).

 

[gazdkw82]

you're not testing pfc. you are testing to ensure that all line - line voltages are 400V (415 in real world).

Yeh I understand that but with PFC, isn't the meter just making a calculation using voltage and loop path? No more dangerous than measuring voltage between phases?

Is that right?

 

[telectrix]

not more dangerous at all.but some mft's won't measure L - L pfc. also bear in mind that all meters can only measure current. it's the range/scalethat you select that makes the meter tell you volts or resistance.

 

[gazdkw82]

not more dangerous at all.but some mft's won't measure L - L pfc. also bear in mind that all meters can only measure current. it's the range/scalethat you select that makes the meter tell you volts or resistance.

Ah ok i understand that. So i guess the question still stands. Will I be expected to test between phases for live polarity, bearing in mind they dont want you testing between phases for PFC

 

[telectrix]

yes. this test is to confirm line - line voltages. if you has . say, L2 with no line supply, your meter may read 230V L2 - E as a false voltage. but measuring 400V L1 -L2 would confirm.