Am2 / testing help.

[ph03nix]

Hi i am new to the forum but found it a great help over the past week.
especially the threads to do with the am2.

My am2 is coming up and i have very little experience with testing.

These questions might seem trivial or simple but i don't want to throw away a good result over a silly mistake.

On the Schedule of test results i have to fill in, under Continuity there is three headings.

(you only have to fill one of the first two in)

(R1+R2) // R2 // Rings

When carrying out the continuity of final ring circuit, which two columns should i fill in, and what exactly is the 'RINGS' column asking me?


Another question i have is to do with polarity.

Do you have to prove polarity for a three phase circuit, and if so how do i do this?
Can i simply set the meter to the bell setting and bell L1-L1, L2-L2 and L3-L3 to prove how its labeled is how its wired? or am i not understanding what its asking me.


Any help would be appreciated, thanks.

 

[spsparks]

r1+r2 are your phase earth continuity readings
r2 is your cpc resistance and is usually omitted if you have the r1+r2 readings
Rings ... I am not sure what you mean here but probably are the end to end values of the ring cpc to cpc n to n ph to ph
3 phase tests are I/R test ph1ph2ph3toN then ph1ph2ph3toE
earth loop, pfc and phase rotation
3 phase R1+R2 ph1-e, ph2-e, ph3-e take the highest value,
you would use a live polarity test with a suitable test lamp but cant see the point if you test as above ..........each phase to n -----on each phase to earth ----on n to e ----off
why not ask your lecturer to clarify

http://www.tlc-direct.co.uk/Book/8.4.1.htm is out of date but illustrates the theory reasonably well

 

[IQ Electrical]

On the model Schedule of Test Results, you perform the end to end ring tests and then the cross connections steps 2 and 3 as per Guidance Note 3.
This gives you an R1+R2 value and a tick for your ring continuity box. You also confirm polarity at the same time.

You should get Guidance Note 3 without delay, it's the testing bible and really, no trainee electrician should be without it!

 

[ph03nix]

Thank you for the reply, kind of under-explained myself.

I'm fine with the test procedure, just the 'RINGS' column is throwing me, is it simply asking for a tick in the box to confirm that ring continuity is ok?

 

[IQ Electrical]

Thank you for the reply, kind of under-explained myself.

I'm fine with the test procedure, just the 'RINGS' column is throwing me, is it simply asking for a tick in the box to confirm that ring continuity is ok?

Exactly, the IET model forms are abysmal!

 

[telectrix]

Thank you for the reply, kind of under-explained myself.

I'm fine with the test procedure, just the 'RINGS' column is throwing me, is it simply asking for a tick in the box to confirm that ring continuity is ok?

i assume it's the end / end resistance of L,N, E, proving that the ring is in fact a ring. i.e.continuous from one end to tother

 

[ph03nix]

Couldn't agree more.
Thanks again for the quick reply.

 

[markysparky]

Many students are failing the testing so "wise up"

Don't forget the following:

Check leads and null before use or if you use the yellow Robins, note the resistance of the leads and take away from reading

Continuity of main bonds and earth
R1 + R2 (best method for the AM2. Proves polarity when you flick the switch on the lighting)
Final Ring Main Test. (Tick in the box on the form and put the results of the end to ends in the comments box)
IR Test (Prepare the installation. Remove lamps and 2d fitting, it plugs in, remove the CO2 detector, disconnect RCBO, switches on, breakers on and test at 500V and DONT FORGET TO OPERATE THE 2-WAY and INTERMEDIATE LIGHTING SWITCHES when testing. Test as per Guidance Note 3. Think about how you are going to do IR test on the cables from the bottom of the contactor to the motor as the contactor will be O/C when you test
Zs (Add Ze to R1 + R2 and insert it in the Zs box and check the readings against the maximum in the onsite guide. SOME MAY NOT COMPLY so check carefully
RCD (Again check guidance note 3)
Functional and phase rotation.

Somewhere on this forum there is help with filling out the schedule of inspection. It is very good so have a good look as well as looking at GN3.

As I said a lot of students are failing the testing as the build is now much easier but my advice for the build is FOLLOW THE SPEC AND DRAWINGS you are giving. Some students are failing as they are not following them exactly.

Not always how its done onsite but I believe thats how its done for the AM2 test.

Test sheets are here. Forms for electrical contractors - IET Electrical

Hope that helps

Markysparky

 

[taza]

hi

as far as the rings column is concerned i think it is simply a tick in the boxes for the ring circuits which in this case is only one!
i did my am2 a few months ago and i think this is the part you are talking about!

 

[ph03nix]

Many thanks markysparky i have done a lot of revision the past couple of weeks and i will be as ready as i can for my am2.

Yes taza thats the part im talking about. Thank you.

Thanks to all who replied, good to know the forum is nice and active.