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Maintaining a DC motor is important to ensure it lasts a long time, doesn’t break down unexpectedly, and runs as efficiently as possible.
If you’re responsible for maintaining equipment, following these steps will help ensure your motors run reliably, increase your productivity, and reduce your repair costs.
Here are ten maintenance tips to help you keep your DC motors running smoothly.
Regular DC motor maintenance includes checking the condition of the brushes and commutator, testing the insulation resistance, and lubricating the bearings. Performing these tasks will help your motors run more efficiently, reduce downtime, and keep your operations running smoothly.
1. Check the Brushes and Commutator
Brushes and commutators are critical components in DC motors and should be inspected regularly. The brushes wear down as they rub against the commutator. If they wear down too far, they can cause sparking, power loss, or even motor failure.
Check the length of the brushes and inspect the surface for wear, chips, or burning. If the brushes are shorter than the manufacturer’s specifications, replace them to ensure they make good contact with the commutator.
What Happens If You Don’t Do This?
If you don’t maintain the brushes and commutator, they can create excessive sparking.
This can cause the motor to overheat and damage other components. This can lead to expensive repairs or complete motor failure, which can cause unexpected downtime and reduce your productivity.
2. Check the Insulation Resistance (IR)
Measuring the insulation resistance (IR) is an important step to ensure the motor is electrically sound. You should use a 500V insulation tester to measure the IR of the field and armature circuits. The IR should be greater than 20 MOhms.
This test will help you identify insulation breakdown due to moisture, dust, or age.
What Happens If You Don’t Do This?
If you don’t measure the insulation resistance, you won’t know if moisture or dust is building up in the motor.
This can cause a short circuit, which can damage the internal components and cause the motor to fail. This will increase your repair and replacement costs.
3. Keep It Properly Lubricated
Lubrication reduces friction, which protects moving parts such as bearings and prevents them from wearing out.
You should lubricate the motor according to the manufacturer’s recommendations. If you over-lubricate the motor, the excess lubricant can attract dust and create a buildup that can reduce the motor’s performance.
What Happens If You Don’t Do This?
If you don’t lubricate the motor, the friction on the moving parts will increase.
This will cause them to wear out, make noise, and overheat. The bearings will wear out quickly, which can cause the motor to fail. This will increase your repair costs and cause downtime.
4. Check the Armature Resistance
Testing the armature resistance is an easy way to identify electrical problems.
You should use a calibrated ohmmeter and compare the readings to the manufacturer’s specifications. This will help you identify damaged windings or weak connections.
What Happens If You Don’t Do This?
If you don’t measure the armature resistance, you won’t be able to identify electrical problems such as damaged windings or loose connections.
This can cause the motor to generate excessive heat and reduce its efficiency.
5. Check the Temperature and Cooling System
Controlling the temperature is important to prevent the motor from overheating.
You should inspect the fans, vents, and heat sinks for dust buildup. This can restrict airflow and reduce the effectiveness of the motor’s cooling system.
What Happens If You Don’t Do This?
If you don’t control the temperature, the insulation will break down, the lubricant will degrade, and the mechanical components will wear out.
This will reduce the life of the motor and increase your repair costs.
6. Check for Vibration
Vibration analysis is an effective way to identify problems such as misalignment, bearing wear, or loose components.
You should use a vibration meter to establish a baseline and monitor the motor for sudden increases in vibration.
What Happens If You Don’t Do This?
If you don’t monitor the vibration, it can cause the motor to become misaligned and put excessive stress on the components.
This can cause significant damage to the internal components and increase your downtime and repair costs.
7. Keep the Motor Clean
Dust and dirt can affect both the insulation and the moving parts.
Wipe the outside of the motor with a rag and vacuum the ventilation openings to remove dust and dirt.
What Happens If You Don’t Do This?
Dust buildup can block airflow, causing the motor to overheat and the insulation to break down. This will reduce the efficiency of the motor and cause it to fail prematurely.
8. Tighten the Electrical Connections
Loose electrical connections can cause the motor to lose power or spark.
Check all the electrical connections, especially at the terminals and junctions, and tighten them if they’re loose.
What Happens If You Don’t Do This?
Loose electrical connections can cause arcing, which can damage the electrical circuits and cause the power to go out.
9. Store and Handle the Motor Correctly
Use the First-In-First-Out (FIFO) method to manage your motor inventory.
Keep the motor in a dry, temperature-controlled environment, cover it to keep the dust off, and don’t set it directly on the ground.
What Happens If You Don’t Do This?
If you don’t store the motor properly, moisture, dust, and temperature fluctuations can cause the motor to corrode, the seals to wear out, and the lubricant to break down.
10. Perform Preventive Maintenance
A preventive maintenance schedule will help you keep up with all the things you need to do to keep the motor running and prevent it from breaking down.
Keep a record of each inspection, including the amount of brush wear, insulation resistance, and lubrication.
Summary
DC motors are used in a wide variety of applications. If you take care of them, they’ll last for many years. If you follow these ten tips, you’ll reduce downtime and improve the efficiency of the motor.
You’ll protect your investment, improve productivity, and extend the life of the motor.
