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IEC Leads and their associated equipments

PATGuard 3 Forum

IEC Leads and their associated equipments

Postby Rigger1963 » Tue Dec 20, 2011 7:43 pm

Hi all,

I'm new to PAT testing, having qualified in the middle of the year and have just really started in earnest the in house testing of school equipment.

The question is this:
I test an IEC lead using the 350 and it passes the earth continuity. I then attach the IEC to its equipment and the 350 fails the test. eg. IEC 0.08 ohms, combined 0.13 ohms. Should I test the equipment with the supplied IEC test lead for extension leads, test that IEC lead and subtract the the resistance from the combined test lead/equipment test, before adding that sum it to the original IEC lead results?

If so, how do I record a pass when the 350 will only record what it gets?
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Re: IEC Leads and their associated equipments

Postby Alan Freeman » Tue Dec 20, 2011 10:07 pm

The simple answer is that you are allowed 0.1 ohm on the equipment PLUS the resistance of the cable.

Assuming 3 metres of 1.0mm2 cable the resistance is 0.06. Add these together, a pass of 0.16 is accesptable.

From the instruction manual:-

"Press Setup (F3) to set the Test Duration and Pass/Fail limit. Use the arrow keys to highlight and set.
The pass/fail limit can be calculated whilst in this mode by pressing Calc (F3). Enter the type and length of cable and a new limit will be calculated. This can be overridden by selecting the limit from the list. Press OK (F4) when complete. Esc (F2) will exit setup mode without saving changes."

Hope this helps!
Alan Freeman
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Re: IEC Leads and their associated equipments

Postby Grizzly » Wed Dec 21, 2011 12:23 am

Rigger1963 wrote:eg. IEC 0.08 ohms, combined 0.13 ohms.

Earth Continuity pass limit = (0.1 + R) Ω where R is the resistance of the protective conductor of the supply cord (IEE Code of Practice, Table 15.1 (page 74)

In your example, R = 0.08Ω, so the measurement for the equipment is 0.13 - 0.08 = 0.05Ω
Well within the 0.1Ω needed, and so a pass.

The passage Alan quotes above can be found in Chapter 11.1 (page 51) of your PrimeTest 350 Operating Instructions.
C&G 2377 -01 & -02
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