July 17, 2008
Motor Tip
A reader recently asked the question how could preventive maintenance be promoted to management on the basis of energy savings.
One fact related to electric motor operations is that rewound motors operate less efficiently than new motors.
By definition, a “burned out” motor has suffered from a mechanical failure. The winding insulation failed to contain the electric current - regardless of the cause (thermal breakdown, chemicals, vibration, voltage spikes, or moisture.)
Motor rewind shops will agree that seldom - if ever - is it feasible to rewind a motor more than once. This is due to the cumulative damage to the windings during failure.
Rewind shops will also admit that not all motors can be rewound, for the same reason. What they may be reluctant to admit is that rewound motors will operate less efficiently than new motors. Depending on who you talk to, estimates range from 50% to 90% efficiency for rewound motors versus new. Hence, it can be demonstrated that repaired motors will increase energy consumption.
This is avoidable by:
#1: Only replacing failed motors with new motors.
Or
#2: Monitoring motor condition and taking worn motors offline BEFORE they fail.
Worn motors can be “reconditioned”, that is reinsulated before any damage to the windings occurs. A reconditioned motor returns to like new efficiency and capacity.
In addition, the cost of reconditioning is usually less than half that of rewinding, and nearly 100% of worn motors can be reconditioned.
Of course, this is contingent on “catching” motors before they fail. What is required is lucky timing for a manual test or the use of automatic testing systems - like MEG-Alert.
So preventive maintenance CAN lead to lower operating costs, AND lower maintenance expenses, overall. Proactive maintenance will ALWAYS cost less than reactive, emergency repairs!
Reader tip by Randy Reek
MEG-Alert
Hot Springs Village Arkansas
Thanks Randy - your stainless steel, diamond plate, Reliabilityweb.com coffee mug is on the way
