Motor Troubleshooting

Winding insulation breakdown and bearing wear are the two most common causes of motor failure, but those conditions arise for many different reasons.

What is the first thing you should do when troubleshooting a motor?

For the supply, test first with the motor disconnect open and locked out. ... Final tests and procedures.

1. Listen for unusual noises.
2. Smell for smoke or hot insulation.
3. Feel the motor for excessive heat or vibration.
4. Look for possible obstructions.

How do you check a motor problem?

How To Check If an Electric Motor Is Going Bad

1. Check the Bearings and Shaft. A motor's bearings are one of the most common components to go bad.
2. Inspect the Motor Windings With a Multimeter. ...
3. Test the Power With a Multimeter. ...
4. Ensure the Fan Is in Good Shape and Secure.

What are the faults in motor?

5 Common Faults In Electric Motors

• High Temperatures And Overheating. Most motor failures and deterioration can be due to exposure to extreme heat.
• Accumulation of Dust And Debris. ...
• Sudden Power Surges. ...
• Wear And Damage of Bearing Over Time. ...
• Humidity and Moisture.

What are the symptoms of motor failure?

4 Signs of Electric Motor Failure

• Worsening Performance. Improper mounting and insufficient lubrication are two common causes of a reduction in electric motor performance.
• Loss of Power. A short circuit or electrical overload could cause your electric motor to suddenly shut off. ...
• Overheating. ...
• Vibrations.

What are the three most common electrical problems in an electric motor?

Electric motor problems and solutions

• Low resistance. Low resistance is the most common cause of failure in electric motors.
• Overheating. Overheating is generally caused by either a high temperature in the operating environment or poor power quality. ...
• Electrical overload. ...
• Vibration. ...
• Contamination.

What are the 7 troubleshooting steps?

Troubleshooting methodologies vary, but the following seven steps are often used.

1. Gather information.
2. Describe the problem. ...
3. Determine the most probable cause. ...
4. Create a plan of action and test a solution. ...
5. Implement the solution. ...
6. Analyze the results. ...
7. Document the process.

How do you troubleshoot a mechanical problem?

Here are the five basic steps to troubleshooting equipment breakdowns:

1. Verify a Problem Actually Exists. The troubleshooting process begins with symptom recognition.
2. Narrow Down the Problem's Root Cause. ...
3. Correcting the Cause of the Problem. ...
4. Verify the Problem Is Corrected. ...
5. Prevent Future Issues By Following Up.

What are the common problems found in a 3 phase motor?

The main types of external faults experienced by these motors are over loading, single phasing, unbalanced supply voltage, locked rotor, phase reversal, ground fault, under voltage and over voltage.

How do you know if motor winding is good or bad?

Testing for short to ground Using Ohm meter: Disconnect all power from machine. Check all three wires singly T1,T2,T3 (all three phases) to the ground wire. Readings should be infinite. If its zero or reads any continuity at all, then a problem exists with either the motor or cable .

How do you check a motor capacitor?

To test a single capacitor. Use a probe to touch one of the terminals. And the second probe to touch

What does it mean when a motor hums?

A slightly misaligned or bent motor shaft will produce a humming sound. A similar noise can be created if there is a minor fault in the transmission equipment attached to the motor shaft. The latter can be confirmed by disconnecting the motor shaft from the load and turning it on.

Why does a motor run slow?

Worn bearing: Worn bearing increases the friction between shaft and motor, this will rise in temperature and decreases the speed of the motor. Shorted running winding: When running winding is shirted then excessive current is flow and the motor will burn.

Why do motors overload?

Motor overload occurs when a motor is under excessive load. The primary symptoms that accompany a motor overload are excessive current draw, insufficient torque and overheating. Excessive motor heat is a major cause of motor failure.

What causes a 3 phase motor to fail?

Phase damage due to unbalanced voltage Thermal deterioration of insulation in one phase of the stator winding can result from unequal voltage between phases. Unequal voltages usually are caused by unbalanced loads on the power source, a poor connection at the motor terminal, or a high resistance contact (weak spring).

What would cause a electric motor not to start?

It might be that the wiring has come loose, or is simply of the wrong gauge. You might also have broken or frayed wiring. All of these issues could prevent the motor from starting up. Make sure you carefully inspect all of the wiring in the starting circuit of the motor.

Can you repair a motor?

So long as the shell exists, a motor can be repaired and reconditioned. The key is to remember that eventually that motor will need a burnout and rewind before it is insulated again. Then, with proper maintenance and smart reconditioning, there is no limit to how many times you can have that motor repaired.

How do motor windings fail?

Electrical failures disrupt the power supply to the motor. This includes single-phased winding failures (wye- or delta-connected) caused by an opening from a blown fuse, open contactor, broken power line or bad connection. Insulation failures are typically caused by contaminants, abrasion, vibration, or voltage surge.

How do you tell if an electric motor is burnt out?

When a motor burns out, a short circuit occurs in the windings and the motor ceases to turn. You can test for a short circuit by checking the resistance of the windings with an ohmmeter; a reading of 0 ohms (Ω) indicates a short.

Why does my electric motor hum but not turn?

If the motor hums but won't turn when power is applied, it indicates that one phase of a three-phase motor is open, or the start winding of a single-phase motor is open. You can use a clamp-on ammeter to locate the line that is not drawing current in the three-phase motor.