I/R testing

[michufc]

hi someone mentioned to me that the lads he worked with did blanket testing for insulation resistance testing is this possible or do i need to tell him to do the job properly

 

[Spudnik]

Perfectly ok, however, if any results were sub standard then each circuit should be tested one by one.

 

[michufc]

so how do i go about doing the test like that then cheers mate

 

[AMST09]

Just do a test at the intake with all possible combinations only when they fall below the value which you deem exceptable do you need to test them individually
Don't forget all the circuits are resistors in parallel so the value at the intake will always be lower than any of the individual circuits

 

[scotsparky]

BE CAREFULL!!!!!!!!!!! Watch for electronics make sure test 2 way switching in all poitions, ect. However if its a periodic then what i do is Isolate the supply and remove the main incoming neutral. put a temporary link between Phase and Neutral and test from that to earth. If there is low readings then islate circuits one at a time.

( Method 2 guidance note 3)

 

[Gnasher]

Also be warned that if you link between Phase and Neutral and test from that to earth you must note this on your report as you have not tested between Phase and Neutral, and there should be good reason to do this test and not use it because it is easier. One reason to do this type of test is if it is not possible to remove all lamps or neons.

 

[baldsparkies]

Also be warned that if you link between Phase and Neutral and test from that to earth you must note this on your report as you have not tested between Phase and Neutral, and there should be good reason to do this test and not use it because it is easier. One reason to do this type of test is if it is not possible to remove all lamps or neons.

True, list it in your limitations as above or even something like
( Insulation tests between line and neutral are limited on circuits containing voltage sensitive equipment) if thats applicable,at least your testing in the real world.

 

[andekoch]

Also be warned that if you link between Phase and Neutral and test from that to earth you must note this on your report as you have not tested between Phase and Neutral, and there should be good reason to do this test and not use it because it is easier. One reason to do this type of test is if it is not possible to remove all lamps or neons.

If you do this you still test between Phase and Neutral but only at 250V, that way the electronics dont get damaged and you have some measure of confidence but it needs to be noted.

 

[baldsparkies]

If you do this you still test between Phase and Neutral but only at 250V, that way the electronics dont get damaged and you have some measure of confidence but it needs to be noted.

Don't count on the 250v insulation tests not causing problems with electronics.Think!! is it 250v ac your chucking down there ? or 250v dc ? It can and will make the differance between fried or unfried components.