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Howdy Y'all.
Today I had 2 long extenion leads to PAT test (dont go getting all pedanticky on the term now ya hear!).
One is a 240v rolled one with 4 sockets in the side and a 16A commando plug on it (yes I know that its not capable of 16A but it never will be used so).
The other is a 110v extension.
Both are 25m+/- in length. (they are long.)
Earth continuity tests OK
Insulation resistance tests OK.
They both fail on "short" on my UT-528 tester after the above tests both pass OK (its doing the continuty check).
However manually testing them with a digital multimeter and a continuity tester show them both as being wired correctly & 1:1 with no shorts.
Using a megger (Avo BM121) shows them as passing with no shorts between any wire.
I have taken the 240 socket cover off the reel holder, inspected and cleaned that up and its all in good order.
Any suggestions on what may be causing this or how to manually test for this?
What else can I use to test them to find what is actually shorting?
They work fine, they are not causing any problem yet fail on my meter (changed batteries too).
I also tried them on a Metrel AutoPAT MI2143 which is 12 month out of calibration (should be fine) and when doing a test on that it does the 25A earth test and flashes a pass (showing that the result is between the 2 limits of 100uA and 25A).
The only thing I can think that may be the cause is:
The 240V one has a crush in the middle of the cable - but surely I'd be able to measure the resistance between cores using my multimeter or the megger?
The 110V one had a nick in the outer insulation a while back and has a double layer of heatshrink over this. No copper was exposed so I cannot see it being this.
Do I just declare them failed/scrap them (kept for parts ) or can I do some other test to identify what and where the issue is?
I don't have a TDR to hand
????
Today I had 2 long extenion leads to PAT test (dont go getting all pedanticky on the term now ya hear!).
One is a 240v rolled one with 4 sockets in the side and a 16A commando plug on it (yes I know that its not capable of 16A but it never will be used so).
The other is a 110v extension.
Both are 25m+/- in length. (they are long.)
Earth continuity tests OK
Insulation resistance tests OK.
They both fail on "short" on my UT-528 tester after the above tests both pass OK (its doing the continuty check).
However manually testing them with a digital multimeter and a continuity tester show them both as being wired correctly & 1:1 with no shorts.
Using a megger (Avo BM121) shows them as passing with no shorts between any wire.
I have taken the 240 socket cover off the reel holder, inspected and cleaned that up and its all in good order.
Any suggestions on what may be causing this or how to manually test for this?
What else can I use to test them to find what is actually shorting?
They work fine, they are not causing any problem yet fail on my meter (changed batteries too).
I also tried them on a Metrel AutoPAT MI2143 which is 12 month out of calibration (should be fine) and when doing a test on that it does the 25A earth test and flashes a pass (showing that the result is between the 2 limits of 100uA and 25A).
The only thing I can think that may be the cause is:
The 240V one has a crush in the middle of the cable - but surely I'd be able to measure the resistance between cores using my multimeter or the megger?
The 110V one had a nick in the outer insulation a while back and has a double layer of heatshrink over this. No copper was exposed so I cannot see it being this.
Do I just declare them failed/scrap them (kept for parts ) or can I do some other test to identify what and where the issue is?
I don't have a TDR to hand
????