the IR test

[james king]

hi, to day in collage we carryied out the IR test. the Q i have for all you experienced tester is that in GN3 there is a diagram of how to carry out the test. but on the diagram the test leads were connected to the eart terminal and N bar with all cables in both bars

to day in collage we tested it with the EandN wires out of the bars what is the wright and wrong way?

Q2. in GN3 it also states connecting the LandN together say in a connector block and then testing to earth is this classed as mepthod 2?

 

[SimpleSimon]

hi, to day in collage we carryied out the IR test. the Q i have for all you experienced tester is that in GN3 there is a diagram of how to carry out the test. but on the diagram the test leads were connected to the eart terminal and N bar with all cables in both bars

to day in collage we tested it with the EandN wires out of the bars what is the wright and wrong way?

Q2. in GN3 it also states connecting the LandN together say in a connector block and then testing to earth is this classed as mepthod 2?

Neither is right nor wrong. The diagram shows how to do the test across the whole installation across E and N. This would give you a reading across all circuits tested at once. However be aware that if you do this and come across a low reading you would than have to break down and test the circuits individually to find the low IR reading.

Q. 2 yes this is method 2. Use this if you cannot remove voltage sensitive equipment from circuit before testing. Perfect example is ELV downlights with transformers.

 

[james king]

so mepthod 2 bibass the the trannys? thanks for your help

 

[james king]

ok so say i am testing between live and earth but i put my probe on the Ebar and other probe in the mcb. will i pick up Efaults from that reading that accour on other ccts?

 

[SimpleSimon]

ok so say i am testing between live and earth but i put my probe on the Ebar and other probe in the mcb. will i pick up Efaults from that reading that accour on other ccts?

It could happen. So than you would have to disconnect each cpc separately and test L to E on each MCB and earth to find the problem.

 

[james king]

ok so the way im thinking is you may as well test ech cct 1by1 to make sure! although if there is no problam between NandE this would be exeptable

 

[pushrod]

ok so the way im thinking is you may as well test ech cct 1by1 to make sure! although if there is no problam between NandE this would be exeptable

No, in an exam where time is important , or on a job where time is money, testing all the circuits at once could potentially save you a lot of time.

 

[Pip]

Pushrod,

So testing the whole installation is OK, and a good thing to do on an initial look see,
but where do you enter that result on the test results sheet?

 

[malcolmsanford]

Schedule of Results

Sorry saw you already said result sheet, If you test the whole insulation and get +299 or whatever your meter reads then that in each circuit coloumn.

 

[Pip]

Nice, Thanks Malcolm