The Exchange Test Method
LABORATORY TEST METHOD NO. H-13: MEASURING LEAKAGE CURRENT IN ELECTRICAL APPLIANCES
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PURPOSE:
To determine leakage current present between all exposed electrically conductive surfaces of the appliance and ground in order to eliminate potentially hazardous conditions.
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REFERENCE:
Various UL Standards
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TEST APPARATUS AND MATERIALS:
- 3.1 A.C. Leakage Current Tester with positive and negative leads -Simpson Model 229-2, or equivalent.
- 3.2 20 by 20 cm (8 by 8 in.) aluminum foil
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PROCEDURE:
- 4.1 Appliance to be tested in an ''as is" condition.
- 4.2 Detach chassis grounding conductor at attachment plug (if provided with 3-prong grounded plug).
- 4.3 Connect meter probes between any accessible conductive part (positive lead) and the grounded supply conductor (negative lead).
- 4.4 Adjust manufacturer's recommended power supply voltage to 120 or 240 volts, depending on appliance rating.
- 4.5 Five seconds after appliance is turned on, with meter probes connected (see 4.3) measure leakage current. Test with appliance switch in both on and off positions.
- 4.6 If appliance has thermostat control, test thermostat in both "switch open" and "switch closed" positions.
- 4.7 Monitor leakage current until thermal stabilization is achieved under maximum heat condition.
- 4.8 Place aluminum foil over accessible non-conductive area~ (with positive lead) to determine if capacitance induces leakage current is present.
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EVALUATION:
Evaluate leakage current levels by using the following acceptable levels per UL Standards:
- 0.5 milliampere for an ungrounded (2 wire) stationary/portable appliance
- 0.5 milliampere for a grounded (3 wire) portable appliance
- 0.75 milliampere for a grounded (3 wire) stationary/fixed appliance
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REPORT
Indicate amount of leakage current and compare for compliance with applicable UL Standard. Report the results in terms of whether the appliance being tested passed or failed applicable UL requirements.