Digital Surge Testing
Surge testing of A/C electric motors and generator windings displays a accurate
picture of the winding and insulation conditions. Tests made can determine good,
marginal or defective windings and the winding insulation before a major failure
occurs. In many cases actions can be taken to head off these failures, preventing
costly delays and repairs. This digital surge tester applies a predetermined
voltage and captures a sinusoidal wave form for each phase of the unit under
going the test. It also displays megohms and Hi-Pot measurements.
All the information is used to make the correct decision on what
repairs are needed.
This is a Surge Test:
The wave form showing a good winding.
You will notice how each of the three phases overlap each other. Representing what
appears to be only one wave line. Pictured is the windings that are being
tested, no faults are present.
Turn to Turn / Phase to Phase Weakness:
If there is a Turn to Turn / Phase to Phase weakness The wave patterns
will separate and appear unstable This is an indication of imminent failure.
The motor should be serviced immediately. Pictured is a turn to Turn / phase
to phase fault.
If there is weak insulation the wave pattern
will indicate the weakness. If a motor with a turn to turn fault short stays in service
circulating currents may produce hot spots and the ground wall insulation will eventually
burn up causing a shut down. Pictured is a ground fault.