reading test meter????

[evs44]

Hi all ive got a dumb question about the robin dig insulation tester.

Im about to carry out my practical exam 2330-3 testing and inspecting. The problem is i havn't done any testing and i dont know how the robin works. I carried out an insulation resistance test at college and i didn't understand the reading. When i did it i got the number 1 and i think a full scale reading which i presume meant over scale.

What should i be getting on the screen if the insulation resistance is ok?

Cheers

 

[Spark123]

Infinity is good, above 1Mohm on a normal mains circuit tested at 500vDC is a pass, however if it is less than 2Mohm it should be investigated further.
If you touch your leads together on the tester you should see it go to 0M ohms which proves your tester is working.
If I were you I'd ask your lecturer to explain the purpose of the test again. Basically it is to ensure the insulation of the circuit i.e. the plastic between the live neutral and earth conductors is sound.

 

[Click-Sure]

My megger 1553 displays >299 Mohms when the leads are not connected to each other or any thing.

Its also gives this reading when I test new or good condition cables.

 

[disinfo]

my old robin used to display o.t. when the test was out of range.

 

[ebee]

Might I suggest consulting the manual if you have it or contacting the manufacturer?

You might be able to download a manual.

Mine shows 999 if "infinity" or an actual reading if less

Good luck with the exam

 

[dingbat]

Basically it is to ensure the insulation of the circuit i.e. the plastic between the live neutral and earth conductors is sound.

Actually, considering that air is often used as an insulator, this is misleading. The test is to check that all conductors are electrically separate from each other.

On the Robin the '1' with a up-arrow means over-range. You record it as >20, >200 or >2000, depending on which range you have selected.

The term 'infinity' has not been recognised for many years and was always, technically, incorrect.

 

[evs44]

Thanks fella's all your info has helped.....

 

[ebee]

"The term 'infinity' has not been recognised for many years and was always, technically, incorrect."

Yes indeed, did it get disbanded when Centrifugal Force was done away with or was it at another time?

In fact we used to get hammered into us the difference between square feet and feet square (pre metric days) but look at the way you write sq mm as mm2 these days.