Electric motors are the almost indefatigable workhorses of industry and modern motors are exceptionally reliable. Nevertheless, when a motor does fail without warning, the consequences can be costly and disruptive. Condition monitoring provides insurance against such failures, by giving advance warning of developing fault conditions. This gives time to plan the required maintenance or motor replacement. To be truly effective, however, condition monitoring must include ‘the missing link’ – electrical tests.
Megger Baker AWA-IV static motor analyzers are the go-to instruments for motor repair, reliability and maintenance professionals who need to understand the electrical condition of motors their organisations depend upon. Weak motor insulation often degrades to the point of causing premature and unexpected motor failure, which in turn can result in costly unplanned downtime of production machinery. The Baker AWA-IV is a fully automated motor analyzer that performs repeatable, user-programmable tests to thoroughly assess the condition of a motor’s insulation and circuit. It is also used to assure quality of motor rebuilds or new production motors before they are placed into service. The Baker AWA-IV is a simple-to-use instrument with an intuitive, touch-screen user interface. It delivers accurate, repeatable results regardless of the operator’s skill level, and easily detects problems that low-voltage testers cannot find by performing a comprehensive set of both high- and low-voltage tests. Results are presented in simple, easy-to-understand graphs and reports that give motor maintenance professionals the information they need to minimize costs and unplanned downtime
The Baker AWA-IV family includes models designed to perform tests at maximum voltages from 2000 up to 12000 volts. Models include 2kV, 4kV, 6kV, 12kV and 12kV HO (high output). These analyzers can be coupled with Baker Power Packs to boost test voltages to 24 or 30 kV for tests on large motors and generators.
BAKER AWA tests:
1. Winding resistance test – Used to detect loose connections and dead shorts.
2. Insulation resistance (Megger) test – Will show if the motor is wet or contaminated, or if it has a dead short to earth. An insulation resistance test alone cannot, however, confirm that a motor is in good condition, as it does not test the entire insulation system
3. Polarization Index (PI) test – The PI test is a 10-minute test that is used to measure/ quantify polarization effects occurring in the ground wall insulation of a motor or generator.
4. DC Step voltage test – Is typically performed at twice line voltage plus 1000 volts. A poor result may suggest contamination or an insulation weakness at that voltage.
5. DC hipot test – The hipot test simply applies a voltage, measures leakage current and calculates insulation resistance.
6. Surge test (BAKER Test) – Used to detect weak insulation both between phases and within one phase, dead shorts, loose connections, and unbalances caused by incorrect winding. The most common cause of electrical faults in motors is between the coils in the in windings. The surge test is the only way to be able to see developing insulation breakdown between each turn prior to total failure. By trending this result planned maintenance can be implemented.
Key Benefits
• Range includes 2 kV, 4 kV, 6 kV and 12 kV models.
• Testing capabilities include: surge, winding resistance, Megohm, PI, DA, continuous ramp DC step-voltage, and DC hipot tests.
• 12 kV HO (high-output) version for performing surge tests on large motors and generators.
• Surge waveform comparison.
• Incorporates advanced inter-turn assessment capabilities in a field portable instrument.
• Local servicing/calibration support now available at the AVO service center in Christchurch.
