Seaward PAT2000i - Manual (Page 13)

The IEE recommends that if testing the protective earth of an appliance results in a
marginal fail, then the appliance should be retested taking into account the length and
cross sectional area of the appliance supply cord. The PAT2000i will automatically
prompt the user if a marginal fail occurs and an appropriate message will be appended
to the stored results if a retest is actioned.
Appendix A details the Earth Continuity Thresholds applicable to each group of
appliances.
EARTH SCREEN TEST
The objective of this test is to ensure that the connection between the earth or
protective conductor of the appliances mains plug earth pin and the metal casing of the
appliance is satisfactory and of low enough value to satisfy accepted safety standards.
The PAT2000i applies a low voltage of approximately 100mV ac rms between the earth
pin of the mains supply plug and the lead connected to the earth bond test terminal, a
maximum current of 100mA is allowed to flow for a period of 5 seconds. The objective
of this test is check the earth screen connection using a current which will prevent
damage or over stressing which may be caused by testing using currents suitable for
earth bond testing.
INSULATION TEST
In the insulation test a nominal voltage of 500V dc is applied between the earth pin and
both the live and neutral pins of the appliance mains supply plug. 110V appliances have
the insulation voltage applied to the earth and the line pins. The PAT2000i displays the
resistance measured and allows the user to confirm sufficient insulation exists. For
Class ll appliances the flash probe replaces the earth pin in the plug, and the default
pass level in manual and automatic modes changes to the appropriate new / service
value.
When the instrument is operating in automatic or manual modes the default insulation
test thresholds are set to the following values.
INSULATION TEST THRESHOLDS
Class I Class II
AS NEW APPLIANCE 2.0 M
Ω
7.0 M
Ω
IN SERVICE APPLIANCE 0.5 M
Ω
1.0 M
Ω
Appendix B details the Insulation Test Thresholds applicable to each group of
appliances.
FLASH TEST
A wide variety of tests are specified under different BS and IEC specifications. For this
reason test voltages have been selected for the PAT2000i which are common for
routine testing without overstressing and potentially weakening appliances insulation
levels. A nominal test voltage of 3kV for Class ll appliances is applied and 1.5kV for
Class I appliances.
NOTE: This particular test may be omitted when testing equipment incorporating
electronics or interference suppressors. This action may be necessary where
the voltage withstand rating of the components fitted to the appliance is
insufficient to accommodate the test without damage.
PAT 2000i Portable Appliance Tester
10
PAT 2000i Booklet 7/3/03 4:26 pm Page 11