5 Easy Steps for Electric Motor Care
Following these fve preventative maintenance steps should ensure your electric motors won’t be the cause of any unintended
downtime on the production line.
By World Wide Electric
To increase the productivity of your electric motors, prevent costly repairs to expensive equipment, and reduce potential operational
downtime, one of the easiest solutions is
to begin a program of regularly scheduled
preventative maintenance. There are of
course associated costs, but these are
considerably less than any that could be
incurred if the line goes down.
We’ve collected fve practical (and simple!) steps for preventative maintenance for
your electric motors that will help you keep
your equipment in great condition and to
maintain operational excellence—
minimizing downtime and keeping your profts up.
Please remember that full preventative
maintenance is a vital part of your daily
or monthly routine, and we cannot provide a full PM plan
here. Instead, our goal is to help you with a good starting
point in your PM process. If, at any point during regular
monthly checks, you notice something out of the ordinary
or potentially dangerous, contact your distributor or manufacturer for more information.
1. KEEP YOUR ELECTRIC MOTORS CLEAN
There are many threats to the health of your electric
motors, but few are as potentially hazardous as a dirty
environment. While TEFC motors are fully sealed to keep
contaminants out of precision inner components, it’s still
important to keep them free of dust, dirt, oil, and debris.
TEFC motors vent heat through their external fns and the
fan, so if they aren’t kept clean, their ability to dissipate heat
is hindered, which could lead to internal damage or failure.
For every 10°C of increased motor operational temperature
above insulation class limits, the life of the internal winding
insulation is cut in half. Debris near seals can also eventually
work their way inward and cause damage as well.
Remember: never clean a motor while it is in operation!
Cleaning a motor when it’s operating can damage it or
cause personal injury. Follow proper lockout procedures
before starting any cleaning operation.
Open Drip Proof motors are even more susceptible to
damage in a dusty or dirty environment as they use an
open-case design to vent heat, and care should be taken
to keep them free from contaminants. It’s also important
to carefully consider your environment when designing your
application to ensure you have the right motor for the job.
High-voltage equipment should always be kept free of dust
and dirt. Dust can be composed of minuscule materials that
are able to conduct electricity, potentially creating damaging
conductive paths where you don’t want them, resulting in
current leakage, unexpected grounding, or short circuits.
For rugged environments, we recommend cleaning your
electric motors and controls once a week. Average conditions
may require fewer cleanings—perhaps only once every quar-
ter or even just twice a year. To keep your TEFC motor clean,
effcient, and cool even in harsh environments, blow out dirt
with no more than 50 pounds of dry, compressed air.
For ODP motors, refer to your instruction manual for
2. SCHEDULE REGULAR EXAMINATIONS FOR
In an industrial environment, all electrical components
should be regularly inspected and, when necessary, maintained. Most electrical failures are a result of moisture,
or loose or dirty connections. A preventative maintenance
schedule can help to identify these issues before they
become critical, preventing such outages and maintaining
your motor performance.
One way to identify potential electrical problems is through
a thermographic inspection, usually performed at peak-load
conditions. This process helps to identify high-temperature
excursions, which are often a result of loose or dirty connections, load imbalances, or incorrectly installed equipment.
To thoroughly check the electrical equipment, schedule
an outage so that all circuit breakers and disconnect
switches can be repeatedly opened and closed to make
sure they operate safely and correctly. Make sure to also
regularly test and calibrate protective relays and circuit
breaker trip devices during the same inspection.
Motors often require different electrical component main-
tenance schedules based on their installed environmental
conditions, the motor’s primary function, and the average
load of the equipment. It is generally recom-
mended to schedule a check at least once
every three years, with a higher frequency for
critical components. Specifc test sets vary
based on the age of the equipment and the
3. CHECK FOR LOOSE COMPONENTS
Some components can become loose over
time, and these loose components can lead to
unexpected or excessive wear. Motor mounts
can even become warped, cracked, or be in
the process of a complete failure. Check your
motor frequently to see if the fttings, mounts,
mounting bolts, steel base plates, and other
components are properly and securely ftted.
Moving parts should also be inspected
for loose pins, bolts, or bearings. A simple
touch with your hand will tell you how well the contacts
and relays operate, or if they stick or bind. Be cautious
when feeling around hot or energized equipment!
4. CHECK THE BELTS ON YOUR ELECTRIC MOTOR
On belt-driven applications, it’s very easy to take your
belts for granted, forgetting about inspections until it’s too
late. A worn belt that fails could lead to equipment damage,
injury to personnel, or even death. Be sure that you regularly
inspect your belts for wear and tension. Most belts should
have about one inch of give and the sheaves should be frmly
seated with no play. Also be sure to verify that the pulley or
sheaves are not worn and within tolerance.
5. SCHEDULE ANNUAL VIBRATION ANALYSIS TESTS
Excessive vibration can signifcantly shorten the lifespan
of your electric motor as it creates wear on metal parts
and can cause bearings and windings to fail.
Excessive vibration can either be a mechanical or electrical issue; mechanical causes are more common. To
check for mechanical vibration issues, examine belts for
proper tension, faulty bearings, or misaligned or imbalanced
components. Pay special attention to parts that rotate,
such as the rotor, rotating load, or drive train, since they
tend to become unbalanced more frequently.
Since excessive vibration may not always be detectable
by hand, certain instruments have been developed to analyze motor vibration. These tools will display the motor’s
amplitude and frequency, alerting the user to potential
issues. For more accurate testing, or identifying the source
of vibrations, consider removing load and running the motor
while checking for vibration.