Appendix A Purpose of Tests
46
For appliances which incorporate over-voltage
protection, a 250V DC test voltage is provided to
allow a reading to be taken without the protection
devices generating a false failure.
Short to Case Test
The Short to Case test applies a nominal voltage of 40V AC RMS to
the appliance and is applied between the Earth pin and both the live
and neutral pins of the supply plug. For Double Insulated
appliances, connect the Earth Bond test clip to the appliance as a
substitute for the Earth.
The Tester measures the current that flows and scales the result to
display a guide to the current that would flow if the test voltage had
been the nominal mains supply voltage, scaled for the applicable
socket.
Please note that values for Short to Case may differ substantially
from that of conventional Earth Leakage tests because of the way
that the test is performed (e.g. it will be affected by the presence of
Neutral-to-Earth suppression capacitors).
This test can prove useful in situations where neither conventional
Insulation nor Flash Tests are acceptable methods of testing the
insulation of the appliance.
Flash Test
1250V/2500V a.c. test voltage
For Metal Cased appliances, a nominal test voltage of 1.25kV AC
RMS is applied between the Earth pin, and both the live and neutral
pins of the appliance mains supply plug
For Double Insulated appliances, a nominal voltage of 2.5kV AC
RMS is applied between the flash probe tip and the live and neutral
pins of the appliance mains supply plug.
