435 neiep
Each phase follows the other by what degree - ANS-120 degrees
If a squirrel cage motor rotation is clockwise with ABC phase sequence, and the phase
sequence ACB is applied, which statement is correct? - ANS-The motor will run in the counter
clockwise direction
The ANS-Walking beam is the device used to prevent starting simultaneously in wye and delta.
ANS-3.58 percent is the slip rate for a six-pole, three-phase, 60Hz motor that rotates at 1157
rpm. 1200-1157= 43
43x100= 4300
4300/1200= 3.58% slip
What is the purpose of the blocked rotor test? - ANS-Determines the normal initial starting
current.
What is the rotating speed of a three-phase 30 Hz 6 pole motor? - ANS-600rpm
30x60=1800 P/2
6/2=3 1800/3= 600
What is the rotating speed of a three-phase 60Hz 4 pole motor? - ANS-1800rpm
60x60= 3600 P/2
3600 divided by 2 = 1800
ANS-1732rpm is the rotor speed for a 4 pole, 60Hz squirrel cage motor with a slip rate of 3.76
percent. What would be the rotor slip frequency for a six pole, 60Hz motor that is rotating at
1170 rpm? - ANS-1.5Hz
60x60= 3600 6p/2
3600/3= 1200-1170= 30
30x100= 3000/1200= 2.5
2.5=.025
.025x60= 1.5Hz
Which of the following best describes the split-phase motor? - ANS-It uses the difference in
winding inductance to offset the phases.
Which of the following is a motor that can be run on both AC and DC? - ANS-Universal motor
Which of the following is repairable on fractional horsepower motors? - ANS-Brush replacement
Which of the following is true about universal motors? ANS: Current flows in the same direction
through the armature and field. Which of the following statements best describes the rotor on a
squirrel cage Indiction motor? - ANS-The rotor consists of heavy bars and rods connected
together at the ends.
Which of the following is true about AC induction motors? ANS: Use a stator as a rotating field.
ANS: The rotational speed of an induction motor's stator's magnetic field. Which statement
describes synchronous speed?
Each phase follows the other by what degree - ANS-120 degrees
If a squirrel cage motor rotation is clockwise with ABC phase sequence, and the phase
sequence ACB is applied, which statement is correct? - ANS-The motor will run in the counter
clockwise direction
The ANS-Walking beam is the device used to prevent starting simultaneously in wye and delta.
ANS-3.58 percent is the slip rate for a six-pole, three-phase, 60Hz motor that rotates at 1157
rpm. 1200-1157= 43
43x100= 4300
4300/1200= 3.58% slip
What is the purpose of the blocked rotor test? - ANS-Determines the normal initial starting
current.
What is the rotating speed of a three-phase 30 Hz 6 pole motor? - ANS-600rpm
30x60=1800 P/2
6/2=3 1800/3= 600
What is the rotating speed of a three-phase 60Hz 4 pole motor? - ANS-1800rpm
60x60= 3600 P/2
3600 divided by 2 = 1800
ANS-1732rpm is the rotor speed for a 4 pole, 60Hz squirrel cage motor with a slip rate of 3.76
percent. What would be the rotor slip frequency for a six pole, 60Hz motor that is rotating at
1170 rpm? - ANS-1.5Hz
60x60= 3600 6p/2
3600/3= 1200-1170= 30
30x100= 3000/1200= 2.5
2.5=.025
.025x60= 1.5Hz
Which of the following best describes the split-phase motor? - ANS-It uses the difference in
winding inductance to offset the phases.
Which of the following is a motor that can be run on both AC and DC? - ANS-Universal motor
Which of the following is repairable on fractional horsepower motors? - ANS-Brush replacement
Which of the following is true about universal motors? ANS: Current flows in the same direction
through the armature and field. Which of the following statements best describes the rotor on a
squirrel cage Indiction motor? - ANS-The rotor consists of heavy bars and rods connected
together at the ends.
Which of the following is true about AC induction motors? ANS: Use a stator as a rotating field.
ANS: The rotational speed of an induction motor's stator's magnetic field. Which statement
describes synchronous speed?
