Question 229Electricity/Electronics - 1st Asst/Chief70% to pass
What can insufficient brush pressure on a DC motor cause?
AI Explanation
The correct answer is B) sparking of the brushes.
Insufficient brush pressure on a DC motor can cause the brushes to lose contact with the commutator, leading to sparking. This sparking occurs because the commutator segments are not making proper electrical contact with the brushes, causing an uneven and inconsistent flow of current. This can lead to accelerated wear of the brushes and commutator, and potentially damage the motor over time.
The other answer choices are incorrect. Insufficient brush pressure does not directly cause excess residual magnetism (A), water vapor absorption (C), or generator overload (D). These issues are typically caused by other factors related to the motor's design, maintenance, or operating conditions.
Related Questions
#227 How may temporary repairs to an open DC propulsion armature coil be made, allowing continued operation until permanent repairs can be made? #228 Besides a condition of overload, what could be a cause of an open armature connection in a DC propulsion motor? #230 An open in the armature of a DC motor is suspected, but is not found by visual inspection of the commutator. What would be the next step in troubleshooting this problem? #231 As shown in the illustration, what type of motor and motor starter are featured? Illustration EL-0137 #232 Referring to figure "B" of the illustrated control circuit schematic diagram, which of the following statements is true when the motor is running in the forward direction? Illustration EL-0011