Seaward A252 - Manual (Page 5)

A252 Portable Appliance Tester INTRODUCTION
E ARTH B OND C ONTINUITY
Most type testing standards, including those referred to above, require that the earth bond resistance,
between all accessible conductive surfaces and the 'earthing' terminal within the appliance, does not
exceed 0.1 Ohm and that compliance should be checked by resistance measurement using a test current
equal to 1.5 times the rated current or to 25 Amps, whichever is greater, from an a.c. voltage source not
exceeding 12 Volts.
The test current for BS415 equipment is limited to 8 Amps due to the wide use of printed circuit tracks in the
earth bond path.
In practice, routine testing will also include the protective conductor (Earth wire) in the supply lead and the
measurement will be made between the earth pin of the supply plug and exposed metal (conductive)
surfaces on the tool or appliance.
WARNING
High current Earth Bond tests may cause damage if inappropriately applied to certain equipment. The A252
does incorporate a special low current (100mA) Functional Earth test for sensitive equipment. If in doubt,
consult the manufacturer of the item before applying any test.
D0010024.DOC (01/01/94) Page 5 INSTRUCTION MANUAL