Two Minute Tips  

Failure to Launch

Noah Bethel | Vice President-Product Development, PdMA Corporation

Failure to Launch

Starting a motor across the line can generate 7-10 times (or more) the normal full load amps and create extreme torque stress on the shaft line components. In addition to these normal stresses on the electrical and mechanical elements of the motor, protection systems like overload and transient sensors are also stressed, often resulting in nuisance tripping.

But sometimes the tripping is not a nuisance and the protection systems are doing their jobs protecting the motor. What do you have in place to distinguish a nuisance trip from a legitimate one? Without some kind of validation, operations can be lulled into thinking that every trip is a nuisance trip, resulting in excessive restarts and an inevitable reduction in life expectancy due to repeated, and unnecessary, starts of the motor.

A simple In-Rush/Start-Up test of current and voltage following a trip can provide a wealth of information on both the electrical and mechanical health of the system in question. This can be the primary data necessary to differentiate between a legitimate vs. nuisance trip and allow reliability analysts and operators to make a quick, informed decision on the next steps to take in expediting a return to productivity.

To see a case study on the use of the In-Rush/Start-Up test to validate a motor trip, visit the PdMA YouTube Channel at:

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About the Author

Noah Bethel Vice President-Product Development, PdMA Corporation

Noah has over twenty-five years of broad operations and electrical systems maintenance experience in industrial, commercial, and military settings ranging from nuclear submarines to world class amusement parks. His experience includes high and low voltage, AC and DC, power generation, power distribution, motors, and motor controllers. Noah is currently in charge of product development for new and existing PdM technology at PdMA Corporation.

Noah is a graduate of the University of the State of New York and the Naval Nuclear Power School and Training Unit. He is a Certified Maintenance Reliability Professional, with field experience in motor circuit analysis, current signature, power analysis, thermography, vibration analysis, oil analysis and ultrasonic testing.