AM2 isolation

[ktguk]

i have just done AM2 and was told i`ll prob have to re-sit isolation of supplies because i isolated like this:

tested the tester:

checked that there was power to the outlet

tested tester again

isolated circuit

tested the tester

checked power was off to outlet

tested the tester again

locked off and signed

an NOT like this:

turn off breaker

lock off and sign

test outlet

test tester

reason being he said was if u were in a large factory or somethin someone could turn it on while you were at the other end, fair enough. but i said well what if the power was already off to what you thought was what you locked off but was from a different DB and some comes and turns it on, so you need to make sure its actually power up first, his answer was... erm well you`ve got to follow the flow chart headbang headbang

i finished the composite 10 hour install in 8 worked first time and no faults he could see. so i said can i redo isolation, but no have to wait for results then miss more work and take a 3-4 hour round trip to isolate something in a dangerous manner (also had to wait about after each section, would have finished in two days and half a mornin otherwise, so is dragged to 3 full days)

 

[foxc01]

Hi mate, I was always taught to isolate the circuit I am working on first before testing for power??

There are 2 parts to your safe isolation, you prove your bay is 'dead' before you install, and then, as you've described, you are given a certain number of scenarios on your completed installation to prove you know how to isolate properly. I was told that I needed to treat the DB as a remote board and that some of my circuits, could be at another end of a factory or building etc, so I thought I have to lock it off before I walk to where I am going to test. Did he tell you this?

I'm not sure if they can fail you on that alone.

I always use the following (you should have had a safe iso checklist with your AM2 pack)

1)ask examiner/customer if ok to turn off power

2) turn off power, and lock it off and use your sign

3) Test your tester

4) prove for voltage between all live phases, phases to cpc and cpc to neutral (remember to put your tester probe to cpc first before phase)

5) Test tester again

Anyway good luck

 

[ktguk]

told me about the distance thing after i finished!! only because i asked what i did wrong coz he sort of emplyed id messed up. you need to prove what your testing is actually what what you`ve isolated other wise it could come live while your working on it, thats the way i did it in 2391 practical and was ok

 

[Andy™]

had the same argument with many lecturers at college.... they said it would never happen, and were not interested. so do it their way for exams, but do it the safe way outside college.

 

[ktguk]

[quote name='Andy

 

[Andy™]

complain. they go on like its a perfect world etc... in which case, why lock it off?!

 

[ktguk]

will wait for results dont know why i cant retake right after as got nearly a full day in saved time, HE EVEN COMMENTED ON HOW FAR I`VE TRAVELLED. just gutted because passed evey electrical exam first time from part 1 to 2301

 

[Apache]

just gutted because passed evey electrical exam first time from part 1 to 2301

That sounds like one hell of a lot of exams

 

[ktguk]

That sounds like one hell of a lot of exams

explains the RSI

 

[sellers]

you see now technically you are correct, because the first step of safe isolation is identify!

In am2 centres they have bay numbers and corresponding isolator numbers so theres your identification. Everyone knows in the real world these tally up only 50% of the time, thus your method. (which is the best method)

It must take a really funny examiner to fail you for this, as you have gone beyond the 'call of duty'

Only way I can see it being a fail if you went over to all the isolators trying them one by one until the bay went dead thus using your testers to identify the circuit, which i highly doubt you did.

 

[ktguk]

you see now technically you are correct, because the first step of safe isolation is identify! In am2 centres they have bay numbers and corresponding isolator numbers so theres your identification. Everyone knows in the real world these tally up only 50% of the time, thus your method. (which is the best method)

It must take a really funny examiner to fail you for this, as you have gone beyond the 'call of duty'

Only way I can see it being a fail if you went over to all the isolators trying them one by one until the bay went dead thus using your testers to identify the circuit, which i highly doubt you did.

no just isolating by circuit as he asked, and same way i isolated in 2391 prac, i finished the am2 in two days (2 thirds of the time) and he still wouldnt let me redo the safe isolation his way, have to wait for results then come back to liverpool from north wales and pay