1. When does a motor operate poorly? 2. What should be done in case the motor is overloaded?
3. What should be done in case the fuses are faulty?
4. What should be done in case the rheostat is shorted?
5. What should be done in case the brushes spark?
6. What should be done in case the pressure is low?
7. What should be done in case the ventilation does not operate?
8. What should be done in case the rotor brushes against stator?

1. Motor operates poorly when it experiences issues such as decreased power output, unusual noises, overheating, or frequent tripping of circuit breakers. These issues can be caused by various factors such as worn-out components, incorrect voltage, or improper maintenance.

To determine the specific cause of the poor motor performance, the following steps can be taken:
- Check the power supply: Ensure that the motor is receiving the correct voltage and that there are no fluctuations or imbalances in the power supply.
- Check for mechanical issues: Inspect the motor for any loose connections, damaged wiring, or worn-out components such as belts, bearings, or gears.
- Check for electrical issues: Verify that all electrical connections are secure and tight, and check for any signs of insulation breakdown or short circuits.

2. If the motor is overloaded, immediate action should be taken to prevent damage and ensure safety. Overloading can occur when the motor is required to work beyond its capacity or when there is an excessive power demand.

In case of motor overload:
- Disconnect the power supply: Safely turn off the motor and disconnect it from the power source.
- Reduce the load: Identify and reduce the load that the motor is operating under. This could involve reducing the mechanical load or adjusting the operating conditions.
- Allow the motor to cool down: Overheating can further degrade the motor's performance, so it is essential to allow it to cool down before restarting.
- Inspect for underlying issues: Once cooled down, investigate the cause of the overload. It could be due to incorrect motor sizing, mechanical issues, or electrical faults. Address the underlying problem to prevent future overloading.

3. If the fuses are faulty, they need to be replaced promptly. Faulty fuses can cause interruptions in the electrical circuit and lead to motor failure or damage.

To replace faulty fuses:
- Disconnect the power supply: Ensure that the motor is safely turned off and disconnected from the power source.
- Locate the faulty fuse: Identify the specific fuse that needs replacement. Fuses are usually located in the motor control panel or the main electrical panel.
- Remove the faulty fuse: Using the appropriate tools, carefully remove the faulty fuse.
- Install a new fuse: Select a fuse of the correct rating and install it securely in place of the faulty one.
- Test the motor: Once the new fuse is in place, reconnect the power supply and test the motor's operation to ensure that the issue has been resolved.

4. If the rheostat is shorted, it can affect the motor's speed control or cause it to operate at maximum speed. A shorted rheostat means that there is a direct connection between the terminals, bypassing the necessary resistance.

To address a shorted rheostat:
- Disconnect the power supply: Safely turn off the motor and disconnect it from the power source.
- Inspect the rheostat: Identify the shorted terminals or any visible signs of damage, such as burnt or melted components.
- Replace the rheostat: If the rheostat is irreparable, it should be replaced with a new one of the correct specifications.
- Test the motor: Once the new rheostat is installed, reconnect the power supply and test the motor to ensure that it functions properly.

5. If the brushes spark, it indicates poor contact between the brushes and the commutator, which can lead to reduced motor efficiency and eventual failure.

To address sparking brushes:
- Disconnect the power supply: Safely turn off the motor and disconnect it from the power source.
- Inspect the brushes: Determine if the brushes are worn out, damaged, or improperly aligned. If there is excessive brush wear, they may need replacement.
- Clean the commutator: Use a brush or cloth to gently clean the commutator surface, removing any debris or build-up that may be preventing proper contact.
- Adjust or replace brushes: If the brushes are misaligned or damaged, they should be repositioned or replaced with new ones following the manufacturer's guidelines.
- Test the motor: After addressing the sparking brushes, reconnect the power supply and test the motor to ensure that the issue has been resolved.

6. If the pressure is low, it can affect the motor's efficiency, performance, and output. Low pressure may indicate a problem with the fluid or air supply system that powers the motor.

To address low pressure:
- Check the fluid or air supply system: Review the components responsible for providing pressure to the motor. This could include pumps, compressors, pipes, filters, or regulators.
- Inspect for leaks or blockages: Carefully check all connections, valves, and lines for any leaks or blockages that could be causing the pressure drop.
- Clear blockages: If blockages are identified, remove them or clean the affected components to restore proper flow.
- Repair or replace faulty components: If any components are damaged or malfunctioning, repair or replace them as necessary.
- Test the motor: Once the pressure issue has been addressed, reconnect the power supply and test the motor to ensure that it operates at the desired pressure level.

7. If the ventilation system does not operate, it can cause the motor to overheat, leading to reduced performance, increased wear, and potential damage.

To troubleshoot a non-operating ventilation system:
- Check the power supply: Ensure that the motor's power supply is functioning correctly and providing the necessary energy for the ventilation system.
- Inspect for obstructions: Check for any debris, dirt, or blockages that may be preventing the ventilation system from operating effectively.
- Clean or replace filters: If the ventilation system has filters, clean or replace them to ensure unobstructed airflow.
- Inspect the fan: Check if the fan blades are intact, properly aligned, and free from any obstructions. If necessary, clean the fan or repair/replace it if damaged.
- Verify connections and controls: Ensure that all wiring and controls associated with the ventilation system are properly connected and functioning as intended.
- Test the motor: Once the ventilation system is repaired or cleared of any issues, reconnect the power supply and test the motor to ensure that the ventilation is operating properly.

8. If the rotor brushes against the stator, it can cause mechanical damage to the motor and disrupt its smooth operation. This condition, referred to as "rubbing" or "contact," can lead to increased friction, heat generation, and potential electrical faults.

To address rotor-stator rubbing:
- Disconnect the power supply: Safely turn off the motor and disconnect it from the power source.
- Inspect for visible damage: Carefully examine the rotor and stator for any signs of physical contact, such as scratches, marks, or deformation.
- Adjust rotor position: If there is rubbing, adjust the rotor's position to ensure an appropriate air gap between the rotor and stator. The manufacturer's guidelines should be followed for proper alignment.
- Repair or replace damaged parts: If there is significant damage to the rotor or stator, it may be necessary to repair or replace the affected components.
- Test the motor: Once the necessary adjustments or repairs have been made, reconnect the power supply and test the motor to ensure that the rubbing issue has been resolved.

Remember, it is essential for qualified professionals or trained technicians to handle motor-related issues to ensure safety and proper resolution.