Test & Measurement

Tip of the Week: Motors and Moisture, Part 2

Aug. 14, 2017

A motor that is exposed to too much moisture might be unable to start.

In Part 1, we observed that excessive moisture can cause a motor to run hot. But this assumes the motor will start in the first place. If the moisture is bad enough, the motor won’t even do that.

Using a vented motor in a wet location is one reason this can happen. Sometimes “wet location” is not obvious to the original specifier.

Perhaps the motor serves a location where the process is dry. That doesn’t mean the location is always dry.

It might be outdoors, or it might be subject to wash down by operators using hoses. In the latter case, it means operators must pay special attention to the vents. You can’t assume that water simply will fall gently over the top of the motor and a drip shield will prevent moisture saturation.

Before specifying a motor, make a thorough assessment of the conditions it is likely to face in the particular application. An unanticipated wash down for an incorrectly specified motor can result in significant downtime.

About the Author

Mark Lamendola

Mark is an expert in maintenance management, having racked up an impressive track record during his time working in the field. He also has extensive knowledge of, and practical expertise with, the National Electrical Code (NEC). Through his consulting business, he provides articles and training materials on electrical topics, specializing in making difficult subjects easy to understand and focusing on the practical aspects of electrical work.

Prior to starting his own business, Mark served as the Technical Editor on EC&M for six years, worked three years in nuclear maintenance, six years as a contract project engineer/project manager, three years as a systems engineer, and three years in plant maintenance management.

Mark earned an AAS degree from Rock Valley College, a BSEET from Columbia Pacific University, and an MBA from Lake Erie College. He’s also completed several related certifications over the years and even was formerly licensed as a Master Electrician. He is a Senior Member of the IEEE and past Chairman of the Kansas City Chapters of both the IEEE and the IEEE Computer Society. Mark also served as the program director for, a board member of, and webmaster of, the Midwest Chapter of the 7x24 Exchange. He has also held memberships with the following organizations: NETA, NFPA, International Association of Webmasters, and Institute of Certified Professional Managers.