Anomalies whilst testing

[davetolladay]

Hi I'll be number 2 then.
Having done the PASS course and played with my tester for a few days, i have now just completed the tests at work.
I have started to put the results into the SimplyPATs software.
Problem is i have some discrepancies regarding the pass or fail rates attributed to the tests. The Primetest 100 seems to allow an earth bond pass of 0.2 ohms where the "official" pass is supposed to be 0.1 ohms plus R. Obviously for longer cable lengths.
Out of 327 tests on all the office and kitchen equipment at work I seem to have quite a few anomalies.
i.e. IEC leads that are a "standard" 2m long, @ 10A that fall ouside the 0.1 ohm mark by .05 or more, ie 0.16 ohm.
Also some of the equipment when tested directly using the red IEC lead supplied with the Primetest 100 can also be outside, ie a PC 0.17ohm, a laser printer 0.13ohm,
and directly testing, a 3kw convector heater 0.18ohm and a 3kw 13a fan heater 0.19ohm.
Are these items "allowed" to pass as the tester says, or should I be red stickering them?
The Simply PATs software can be adjusted to allow a higher pass rate, but should I do it?
I remain yours, somewhat bemused.
Dave T

[passadmin]

Hi There,

May I first point out that the software database should never be “tweeked” to achieve a pass when PA Testing and the short red IEC lead supplied with the Prime Test 100 is solely for use when looping back during testing extension leads.

There are two possibilities to account for these experiences. The most likely is that you are not achieving a good earth connection. You have to remember that the earth test current used is only 200 mAmps and the slightest contamination, dirt or paint deposit will give the symptom described. It is wise to carry a piece of emery cloth while PA Testing to brighten up the point of contact to ensure that you are connecting to absolutely bare metal.

The second but least likely reason is that the PT 100 may have drifted out of calibration. Experience tells me that the former is more likely.