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PAT400 Series
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This warning may be repeated on other tests while potential parallel paths exist.
This message can appear on all tests and is caused by:
a.
The equipment under test has an alternative earth path. This could be via the outer case of the equipment touching
other earthed equipment or from touching the ground. Parallel earth paths affect measurement accuracy and in worst
case situations can lead to equipment being passed as safe when there is no proper earth connection through the
electrical outlet.
b.
A hardware fault in the PAT400
c.
A combination of the above.
Any reports of parallel paths should be investigated. Check to ensure If the BOND (continuity) lead is not connected to the null post on
the PAT400. If not, the asset must be checked for additional earth paths. These could be as high as 1.2 kΩ.
The PAT400 can be checked by disconnecting the equipment under test and re-starting the PAT400. If the PAT400 does not report a
fault, the problem exists on the equipment under test.
Testing an asset with multiple earth paths does not confirm the asset is safely earthed.
Additionally, parallel earth paths can affect the accuracy of the measured earth resistance, insulation test or leakage measurements,
therefore creating an unreliable PASS.
