WorksheetsBaldor Motor Basics Quiz (USE PDF)
Total questions: 21
Worksheet time: 11mins
In the USA, utilities that supply AC power to the incoming point of a facility are required to provide power in multiples of how many volts?
100 volts
110 volts
120 volts
130 volts
What is the voltage difference between the two "hot" wires in most single-phase residential systems?
120 volts
240 volts
360 volts
480 volts
Which type of system is described as having a voltage difference of 240 volts between the three "hot" wires?
Single-phase system
3-phase, 3-wire ungrounded system
4-wire grounded wye system
3-phase, 4-wire grounded system
What is the typical voltage rating for single-phase motors operating at 120/208 volts in commercial and industrial settings?
115 volts
230 volts
277 volts
460 volts
What is the classification of a 3-phase, 3-wire delta connected system operating at 2400 volts?
Low Voltage
Medium Voltage
High Voltage
Extra High Voltage
What is the typical voltage range for a motor nameplated at 460 volts?
506 volts to 414 volts
460 volts to 230 volts
500 volts to 400 volts
480 volts to 220 volts
What is the main issue with using a 230-volt motor on a 208-volt power system?
The motor will overheat
The motor will run too fast and overload
The operating voltage on the motor may not be low enough to run
The motor will consume more power
What is the new standard voltage in European countries for motors that can run on either a 380-volt system or a 415-volt system?
220/380 volts
230/400 volts
240/415 volts
250/440 volts
In table 2, what is the system voltage rating for a 3-phase - 3 wire motor in a 50 Hz power system with a supply voltage of 220 volts?
115 volts
127 volts
220 volts
440 volts
In the chart (Typical 3-phase Transformer Connections) which of the following is a 4 Wire Grounded Wye connection in a 3-phase transformer?
(A)
(B)
(C)
None of the above
What happens to the current when the voltage drops below the nameplate rating for an electric motor?
A) The current decreases
B) The current remains the same
C) The current increases
D) The current fluctuates
What is the effect of a 10% voltage decrease on the amperage of an electric motor?
A) 5% amperage increase
B) 10% amperage increase
C) 15% amperage increase
D) No change in amperage
What is the effect of a 10% reduction from nameplate voltage on the starting torque of an induction motor?
A) Reduces by a factor of 0.9
B) Reduces by a factor of 0.8
C) Increases by a factor of 1.1
D) No effect
What is the result of operating an electric motor at 80% of the full voltage value?
A) 64% of the full voltage value
B) 81% of the full voltage value
C) 90% of the full voltage value
D) 100% of the full voltage value
What is a common misconception about the effects of high voltage on electric motors?
A) High voltage increases the amperage draw
B) High voltage decreases the amperage draw
C) High voltage has no effect on the amperage draw
D) High voltage stabilizes the amperage draw
What is the effect of operating a motor at a voltage above its designed voltage?
It will decrease the motor's efficiency.
It will cause the amperage to go up, leading to increased heating and a shorter motor life.
It will have no effect on the motor's performance.
It will improve the motor's performance.
What is the tolerance band for older motors rated at 220/440 volts?
Plus/minus 5%
Plus/minus 10%
Plus/minus 15%
Plus/minus 20%
What is the effect of a 5% increase in voltage on incandescent lights?
10% reduction in bulb life
20% reduction in bulb life
50% reduction in bulb life
70% reduction in bulb life
When dealing with 3-phase, which type of motors are more sensitive to over-voltage?
Single-phase motors
Small motors
Premium efficiency Super-E motors
Two-pole and four-pole motors
What happens to the power factor when voltage is either high or low?
It improves with higher voltage and drops sharply with low voltage.
It drops with higher voltage and improves with low voltage.
It remains constant regardless of voltage.
It improves with both high and low voltage.
In newer installations, the most popular configuration is the 4-wire grounded wye system. The low-voltage supply to this system is 120/208 V. What is the higher-voltage supply rated at?
120/480 volts
1000 volts
277/480 volts
600 volts
