Prime test 100 on extension lead query

[Jake]

Hi,

I did a pat testing C&G about a year ago and have only just started testing. I seem to have had no issues to be questioned until a 30m reeled extension lead with the result as:-

aaa.jpg (242.39 KiB) Viewed 6401 times

Can anyone shed light on this as I do seem to remember something on the length been the reason for the fail but would rather ask the question?

Thanks

[Amy Lyons]

Hi Jake,
When calculating the pass limit for Earth Continuity you should use 0.1 Ohm + R (where R is the resistance of the supply cable). There is a table on page 134 of the IET Code of Practice that will help you to calculate this. Some testers have the facility to calculate this for you however the PT100 does not. Please be sure to always use the values and your own knowledge to decide on pass or fail as the tester is for indication only on pre-set values that are not always relevant.

[Jake]

Hi Amy,

Thanks for your quick response