Seaward A252 User Manual
Page 6
A252 Portable Appliance Tester INTRODUCTION
E
LECTRICAL
I
NSULATION
To check the insulation, between the 'live' conductors (line and neutral) and all exposed metal surfaces, a
high voltage a.c. Flash Test is applied. The voltage applied will be dependant on the construction class of
the tool or appliance -
• 500V the minimum test voltage recommended by the HSE in Guidance Note PM32
• 1250V for standard Class I (earthed) tools and appliances
• 3000V for routine testing of Class II (double insulated) equipment (2500V for BS415 equipment)
• 3750V for Class II equipment following repair or reconditioning operations.
Under normal conditions the permissible leakage current at the appropriate flash test voltage should not
exceed 5mA. However, some Class I equipment may have higher inherent leakage due to an extra long
supply lead or high capacitance suppression filtering, or a combination of the two, under these conditions
an increased acceptance level, of up to 10mA, may be permissible. For certain sensitive equipment it may
even be advisable to not apply a Flash Test but to only carry out a 500V d.c. Megohmmeter test. If in doubt
advice must be sought from the appliance manufacturer.
D0010024.DOC (01/01/94) Page 6 INSTRUCTION MANUAL