Two Minute Tips  

Motor Storage

Mark Koch | Technical Support, ALL-TEST Pro, LLC

One thing that is typically overlooked is how spare motors are stored. Over time, moisture, dirt, dust, and even general vibration from other sources can have a negative impact on the electrical and mechanical condition on the stored motors. Stored motors should be periodically wiped down and cleaned to ensure proper functionality when the motor is installed. The shaft of the motor should be periodically rotated to keep the grease inside the bearings from drying out or separating. It is recommended to rotate the shaft once a month but at a minimum the motor shaft should be rotated quarterly.

High humidity in a storage facility can also negatively impact the insulation system of the motor. Condensation can condense directly on the windings which will start to degrade the insulation material leading to premature motor failure once installed in the machine. If the storage area does reach the dew point, heaters or dehumidifiers should be installed to prevent condensation.

Motor tags are an important component of storage. Motor tags should have general motor data, date of receipt in storage, and the storage maintenance requirements for the motor such as monthly or quarterly shaft turn, insulation & resistance readings. Other maintenance and measurement variables can be added to the tag depending on what criteria and test instrumentation the storage facility employs.

Before installation of the stored motor, ALL-TEST Pro recommends performing a Motor Circuit Analysis™ (MCA™) test to ensure winding degradation has not occurred while the motor has sat in the storage facility. This test can also be utilized as a baseline test that can be compared to and trended to in the future while the motor is in storage or after the spare motor has been installed.

Any change in the TVS signifies a change in the motor windings, ground, rotor, cabling, etc. The initial test should indicate all three phases of the motor are symmetrical and do not indicate any contamination nor ground faults. A TVS™ test value can be compared to future tests on the same motor and any deviation between the values signifies a change in the motor system due to a developing motor fault.

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About the Author

Mark Koch Technical Support, ALL-TEST Pro, LLC

Mark Koch is a member of the Technical Support team at ALL-TEST Pro, LLC (ATP), where he has provided professional support worldwide for users of ATP equipment since 2014. He has 17 years of electrical and reliability maintenance experience. In 2001, he started his career as a construction electrician. During this time, he worked his way up from shop floor apprentice to a foreman in charge of starting and completing remodel and new construction projects. In 2010, he began working at the Metropolitan Sewer District (MSD) of Greater Cincinnati, Ohio, USA, where he learned electrical maintenance best practice and helped implement a predictive maintenance program (PdM). During his service at MSD, his team was the recipient of both the Uptime Magazine’s Best Emerging Maintenance Reliability Program Award and the Uptime Magazine’s Best Asset Condition Management Program Award. At MSD, he learned and provided routine PdM services such as thermography, vibration, lubrication, visual inspection, motor testing, and ultra-sonics.


Education and Certifications:

2001-2006- International Brotherhood of Electrical Workers (IBEW) Apprenticeship Program and the National Electrical Contractors Association (NECA) Inside Wireman Certification.

2013- PdM Visual Testing Level 2 Certification & Level 1 Thermographer Certification; 2014- Vibration Analysis Level 1T Certification.