The Surge Comparison tester checks the strength of
ground insulation that consists of enameled insulation. It
detects the insulation failures such as turn-to-turn
shorts, layer-to-layer shorts, coil-to-coil shorts,
winding-to-winding shorts, and phase-to-phase shorts.
Open circuit and ground detection are other benefits of
The Surge tester uses the principle of impedance balance
to test the quality of electrical windings.The Surge tester
works as a capacitive-discharge system. A capacitor is
charged with high voltage and then discharged into the
winding, through a solid state assembly. This sequence is
repeated thus stressing the insulation of the winding
with high voltage pulses.
The resulting voltage decay pattern of two winding is
then displayed on the CRT. The waveform pattern will be
perfectly superimposed for good windings but in case of
a defective winding a double wave pattern will appear on
the screen as one wave pattern from the good winding
plus the erratic pattern from the faulty winding.
SURGE VOLTAGE = √2 × (2×E + 1000)
where E is the operating voltage