| Question | Answer |
| More motors fail due to ____ than any other reason. | Overloading |
| _____ unbalance is the unbalance that occurs when lines are out-of-phase. | Phase |
| Single phasing is the maximum condition of ____. | Voltage Unbalance |
| All motors produce ____ as they convert electrical energy to mechanical energy. | Heat |
| A ____ is the application of too much load to a motor. | Overload |
| ______ causes metal parts to rust and motor coil insulation to lose some of its insulating driven pulley. | Moisture |
| The ____ of a belt is measured from the center of the drive pulley | Span |
| ____ is usually corrected by placing shims under the feet of the motor or driven equipment. | Misalignment |
| A motor ______ is an imperfection created during the manufactured motor. | Defect |
| Motor _____ is any damage that occurs to a properly manufactured motor. | Damage |
| Water used to clean a motor should no exceed _____ degrees F. | 200 |
| For normal operation, electric motor oil should be added to sleeve bearings of motors after ____ years. | 3 |
| For normal operation, motor ball bearings should be lubricated after _____ years. | 1-10 |
| Motors other than ____ types can usually be mounted in any position. | Drip Proof |
| True/False: Excessive heat is a major cause of motor failure. | True |
| True/False: The insulation class of motors is given in C and/or F. | True |
| True/False : As phase unbalance increases, motor temperature decreases. | False |
| True/False: Motors with a voltage unbalance require derating. | True |
| True/False: Voltage unbalance causes blackening of all stator windings. | False |
| True/False: Single phasing of a delta-connected motor causes severe burning and distortion to two or more phase coils. | False |
| True/False: Over cycling occurs when a motor is repeatedly turned ON or OFF. | True |
| True/False: Couplers compensate for misalignment of the motor and driven load. | True |
| True/False: To force dry a motor, heat is applied for approximately 18-30 hours. | True |
| Whenever more then ____% voltage unbalance is measured, the power company should be notified.
A. 2
B. 4
C. 6
D. 8 | A 2 |
| When one of the 3-Phase lines of a motor no longer delivers voltage to the motor, the motor will ____.
A. not operate
B. operate on one phase
C. operate on two phases
D. not be affected | C operate on two phases |
| Surge voltage is ____ voltage.
A. higher than normal, temporary
B. higher than normal, permanent
C. lower than normal, temporary
D. lower than normal, permanent | A higher than normal, temporary |
| If a motor is drawing rated current, it is ____.
A. barely working
B. working in its lower mid-range
C. working in its upper mid-range
D.working to its maximum | D working to its maximum |
| Motor starting current is usually ____ times the full-load running current of the motor.
A. 2 to 3
B. 3 to 4
C. 4 to 5
D. 5 to 6 | D 5 to 6 |
| When a motor application requires that the motor be cycled often, ____.
A. use a 50 degree C motor
B. use a 1.25 or 1.35 service factor motor
C. provide additional cooling
D. A, B, and C | D A, B, and C |
| When cleaning a motor with water, the water pressure should not exceed ____ psi.
A. 10
B. 15
C. 20
D. 25 | D 25 |
| Single phasing can be reduced by using the ____.
A. proper size dual-element fuse
B. correct heater sizes
C. both A and B
D. neither A nor B | C Both A and B |
| When a motor has failed due to overloading, ____.
A. all motor windings will be blackened evenly
B. there will be obvious damage to the insulation
C. there will be isolated areas of damage
D. A, B, and C | A. all motor windings will be blackened evenly |
| Belt deflection should equal ____" per inch of span.
A. 1/64
B. 1/16
C. 1/4
D. neither A, B, nor C | A 1/64 |
| Type of problem: The first few turns of the windings are burnt and opened. | Voltage Surge |
| Type of problem: All windings are burnt. | Overload |
| Type of problem: One-third of the windings are burnt. (delta connection) | Single Phasing |
| Type of problem: Two-thirds of the windings are burnt. (wye connection) | Single Phasing |
