Two Minute Tips  

Thermal Convection

Bill Kruger | Technical & Training Manager, ALL-TEST Pro

Winding and motor insulation systems follow the Arrenius Equation: A chemical reaction rate doubles for every tempera- ture increase of 10° C, since insulation systems are dielectrics they follow these rules. This means that a motors life decreas- es by 50% for every 10° C increase in motors temperature.

Many electric motors use thermal convection to keep the motor cool. The greater the surface area of contact, the greater heat transfer ability. Fins on the motor enclosure increase the surface area of the motor housing which increases the heat dissipation capabilities of the motor, thereby maximizing the life of the motors insulation systems.

Allowing build-up on the motors exterior limits the motors ability to adequately dissipate heat, dramatically reducing the life of the motors insulation system and the life of the motors. Frequent cleaning of the motors exterior will allow the motors to achieve its expected life.

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Sandesh Patoliya
Sandesh Patoliya
4 years ago

How to calculate the decrease of motor life for increase in motor temp?? Are there any formula??

About the Author

Bill Kruger Technical & Training Manager, ALL-TEST Pro

William Kruger joined ALL-TEST Pro, LLC as the Technical Manager in 2005. Since joining ATP, Bill has traveled the world teaching the Theory and Application of Motor Diagnostics, helping Fortune 500 Companies implement Predictive Maintenance Programs. In 2010 Bill’s proven instructional techniques earned him the new title of Training Technical Manager.

Before joining ALL-TEST Pro, LLC Bill Kruger worked in many different aspects of the Engineering and Maintenance Fields. Bill worked as an Electrician in the US Navy Nuclear Submarine Program. He has completed the Journeyman Electrician Program and started one of the first Predictive Maintenance Programs in the Utility Industry. Bill Kruger holds a Bachelor of Science Degree from San Diego University.

With his combined work in the field as well as with ALL-TEST Pro, Bill has over 40 years of proven experience in the practical engineering and predictive maintenance field.