Voltech AT5600, Руководство пользователя

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C H A P T E R 7 – T E S T S A N D T E S T C O N D I T I O N S
AT5600 User Manual 98-119 issue 14
Page 147
7.33. STRW – Stress Watts
Where Used
The Stress Wattage test tests the transformer for breakdown of insulation by
measurement of the energizing power of a winding, usually the primary, with the
remaining windings open circuit. This test applies the voltage, usually twice the
normal operating voltage, and continually measures the power to determine any
breakdown by changes in the measurement.
This test is suitable for sub-miniature line frequency, large line frequency bobbin
wound and some HF transformers. It checks the integrity of inter-turn insulation,
the magnetic material and joints.
Measurement Conditions
A constant voltage source is applied to the winding under test. Both the RMS
voltage and the power are measured. If necessary, the voltage can be trimmed to
the user specified value, and the measurement repeated. The measurement is
repeated many times until the dwell time has elapsed. The result given is the
measured power.
Usually, the test conditions should be twice the working voltage and frequency
and has the purpose of trying to create an inter-turn breakdown at a point of
potential weakness in the wire enamel. This breakdown is detected by an
increase in the measured power.
Note: Maximum power for this test is 25W
Please also see
14.6.29 for specific advice on programming the test, and
10.2.15 for test accuracy specification