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WorksheetsIDA-201 Final
Total questions: 75
Worksheet time: 1hrs 15mins
Name
Class
Date
1.
If the voltage supplied to the motor is well below the motor rated voltage, the current draw will be ____ it should be.
a)
higher than
b)
lower than
c)
the same as
d)
in reverse polarity than
2.
The voltage tolerance of a standard electric motor is ____.
a)
+10% -10%
b)
+5% -10%
c)
+10% -5%
d)
+15% -15%
3.
The locked-rotor amperage is normally ____ times as great as the run-load amperage.
a)
5
b)
2
c)
3
d)
10
4.
A sleeve bearing would typically be used in a motor that operates with a ____.
a)
light load and where noise is a factor
b)
heavy load and where noise is a factor
c)
heavy load in a dirty atmosphere
d)
heavy load in a moist atmosphere
5.
A slotted screw at the bottom of the bearing housing is called a ____.
a)
relief plug
b)
purge screw
c)
drain plug
d)
retaining screw
6.
A direct-drive motor is usually connected to a load with a ____.
a)
coupling
b)
cradle mount
c)
rigid base mount
d)
pulley
7.
Grounding straps are required on resilient mounted motors to ____.
a)
ground the motor in case of winding failure
b)
prevent rotation of the motor in the mount
c)
help reduce motor vibration transfer to the object on which the motor is mounted
d)
act as the position for locating the motor leads
8.
A motor can burn out if the supply voltage is either too high or too low.
a)
True
b)
False
9.
One method a technician can employ to check a motor is to take amperage readings of a motor (both on start-up and after start-up) and compare them to the motor's nameplate.
a)
True
b)
False
10.
Regardless of the type of motor or application, the motor bearings require yearly lubrication.
a)
False
b)
True
11.
The alternating current frequency supplied by the power companies in the United States is ____________________ hertz.
a)
60
b)
80
c)
50
d)
120
12.
If the applied voltage is too high, the motor may develop local hot spots within its windings, but it will not always experience ____________________.
a)
High amperage
b)
Low Voltage
c)
No amperage
d)
No Voltage
13.
The vertical condenser fan is trying to fly downward into the unit to push air out the top, which puts a real load on the end of the bearing, called the ____________________ surface.
a)
Thrust
b)
Rust
c)
Ground
d)
Drive
14.
In order to be electrically safe, a motor that is set in a "resilient" mount, must have a(n) ____________________.
a)
Ground strap
b)
Electrical strap
c)
Voltage strap
d)
Drive strap
15.
Whenever possible, when changing a motor, the _________________________ should be obtained.
a)
Exact replacement
b)
Does not matter
c)
Similar replacement
d)
Drive replacement
16.
The device that transfers the motor's energy to the driven component is called the _________________________.
a)
drive mechanism
b)
power supply
c)
ground strap
d)
transformer
17.
Explain the locked-rotor amperage (LRA).
a)
The LRA is the amperage the motor draws at start-up before the rotor has started to turn.
b)
The LRA is the amperage the motor draws at cool-down before the rotor has started to turn.
c)
The LRA is the amperage the motor draws at start-up after the rotor has started to turn.
d)
The LRA is the amperage the motor draws at cool-down after the rotor has started to turn.
18.
What is the major advantage of a ball bearing motor over the sleeve bearing motor?
a)
It will handle heavier loads on the bearing.
b)
It will handle lighter loads on the bearing.
c)
It will handle heavier loads on the sleeve.
d)
It will not handle heavier loads on the bearing.
19.
T/F: A motor that is "rigid-mounted" is connected directly to the frame of the equipment and will transmit noise and vibration. A "resilient" mount has a rubber ring that prevents the noise and vibration from transmitting.
a)
True
b)
False
20.
Name four basic methods for mounting motors.
a)
Cradle mount, rigid-base mount, end mount, and belly-band strap mount
b)
Cradle mount, rigid-base mount, front-end mount, and belly-band strap mount
c)
Cradle mount, soft-base mount, end mount, and belly-band strap mount
d)
Cradle mount, rigid-base mount, end mount, and belly-band front mount
21.
A motor's speed is determined by ____.
a)
number of motor poles
b)
amperage
c)
voltage
d)
size
22.
Start windings are placed ____ with the run windings.
a)
slightly out of phase
b)
180 degrees out of phase
c)
in phase
d)
in series
23.
The start windings have ____.
a)
more turns than the run windings
b)
fewer turns than the run windings
c)
the same number of turns as the run windings
d)
larger diameter wire than the run windings
24.
A split-phase has a ____ winding and a ____ winding.
a)
start, run
b)
start, common
c)
common, run
d)
run, common
25.
A split-phase motor that has a current relay and a start capacitor is called a(n) ____ motor.
a)
Capacitor Start, Induction Run (CSIR)
b)
Capacitor Start, Capacitor Run (CSCR)
c)
Induction Start, Induction Run (ISIR)
d)
Permanent Split Capacitor (PSC)
26.
When a Capacitor Start Induction Run (CSIR) motor is running and up to speed, what is the total capacitance acting on the motor? (Assume the run capacitor is 5 microfarads and the start capacitor is 20 microfarads, if present.)
a)
5 microfarads
b)
4 microfarads
c)
20 microfarads
d)
25 microfarads
27.
A permanent split capacitor (PSC) motor that is running and up to speed will have the start winding ____.
a)
energized
b)
de-energized
c)
in series with the run winding
d)
removed from the circuit
28.
When a Capacitor Start, Capacitor Run (CSCR) motor initially starts, what is the total capacitance acting on the motor? (Assume the run capacitor is 5 microfarads and the start capacitor is 20 microfarads, if present.)
a)
25 microfarads
b)
20 microfarads
c)
5 microfarads
d)
15 microfarads
29.
Capacitors wired in series with the starting winding provide a(n) ____.
a)
greater starting torque
b)
longer starting time
c)
aid in starting three phase motors
d)
more efficient operation at full load speed
30.
The shaded pole motor ____.
a)
has little starting torque
b)
has excessive starting torque
c)
has greater efficiency than most split-phase motors
d)
will start against a heavy starting load
31.
Three phase motors have ____.
a)
run windings only
b)
three start and three run windings for each phase
c)
one start and one run winding for each phase
d)
a start switch in each phase circuit
32.
A current magnetic relay opens and closes its contacts based on the ____.
a)
current in the run winding
b)
voltage across the run winding
c)
voltage across the start winding
d)
current in the start winding
33.
The starting device usually used on single phase, fractional horsepower motors requiring low starting torque is the ____.
a)
current relay
b)
potential relay
c)
centrifugal switch
d)
differential relay
34.
The positive temperature coefficient resistor start device is a type of ____.
a)
variable resistor
b)
capacitor
c)
switching device
d)
diode
35.
A permanent split-capacitor motor has a ____.
a)
run capacitor only
b)
start and run capacitor
c)
start capacitor only
d)
split phase capacitor
36.
The contact(s) in a potential type starting relay are normally closed.
a)
True
b)
Fasle
37.
Once the start winding and the start capacitor have been removed for the circuit, the motor will continue to operate with only the run winding energized.
a)
True
b)
Fasle
38.
The contact(s) in a current type starting relay are normally closed.
a)
False
b)
True
39.
The resistances of the windings in a three phase motor are all equal.
a)
True
b)
False
40.
The ______________ is a winding that, when energized, will generate a magnetic field as there will be current flowing through it.
a)
Stator
b)
Potential
c)
Microfarad
d)
Capacitor
41.
The rotating portion of an electric motor is called the ____________________.
a)
Rotor
b)
Cage
c)
Phase
d)
Capacitor
42.
On a potential relay, the coil is connected between terminals 2 and ____________________.
a)
5
b)
1
c)
3
d)
4
43.
What is meant by the "phase angle" in an alternating current circuit?
a)
Phase angle refers to the amount by which the current leads or lags the voltage.
b)
Phase angle refers to the amount by which the voltage leads or lags the voltage.
c)
Phase angle refers to the amount by which the watts leads or lags the voltage.
d)
Phase angle refers to the amount by which the microfarads leads or lags the voltage.
44.
When not air cooled, the heat generated by the motor in a hermetic motor-compressor assembly is removed by what?
a)
Refrigerant Vapor
b)
Refrigerant liquid
c)
Water
d)
Water-Vapor
45.
When a contactor's coil is energized, how much resistance should be measured between terminal "L1" and terminal "T1"?
a)
zero ohms
b)
50-3000 ohms
c)
5000-6000 ohms
d)
infinite
46.
An inherent motor protector is a ____.
a)
thermally activated device in the motor winding
b)
circuit breaker
c)
motor starter overload
d)
line fuse
47.
Standards for motor overload protection are set by the ____.
a)
National Electrical Code
b)
United States Department of Transportation
c)
Environmental Protection Agency
d)
American National Standards Institute
48.
Which of the following overload devices is not affected by ambient temperature?
a)
magnetic
b)
solder pot
c)
bimetal
d)
time-delay fuse
49.
The locked rotor amperage, LRA, of a motor is typically five times higher than the full load amperage, FLA, of the motor and can be as high as seven times the FLA.
a)
True
b)
False
50.
Contactor contacts that are badly pitted can cause the motor to burn out.
a)
True
b)
False
51.
Bimetal and solder pot overload devices are thermally operated.
a)
True
b)
False
52.
Magnetic overload devices are the most accurate type of device for electrical protection.
a)
True
b)
False
53.
If a normally operating motor draws 75 amps on startup, it will most likely draw ____________________ amps when running.
a)
15
b)
10
c)
12
d)
17
54.
The best way to repair a defective relay is by ____________________.
a)
Replacemnet
b)
Fixing
c)
Measuring
d)
Conducting
55.
The most common material used on the surface of contacts is ____________________.
a)
Silver
b)
Gold
c)
Brass
d)
Aluminum
56.
If a relay starts the indoor fan in the cooling mode of a central air-conditioning system, it must be able to withstand the ____________________ of the fan motor on start-up.
a)
Inrush current
b)
Outrush current
c)
Voltage
d)
Resistance
57.
Define a motor starter.
a)
A motor starter is a relay or contactor with built-in overload cutouts.
b)
A motor starter is a relay and contactor with built-in overload cutouts.
c)
A motor starter is a relay or contactor with built-out overload cutouts.
d)
A motor starter is a relay or contactor with built-in overload cut-ins.
58.
Define a relay.
a)
A relay is a magnetically controlled set of contacts that are not replaceable.
b)
A relay is a electrically controlled set of contacts that are not replaceable.
c)
A relay is a magnetically controlled set of contacts that are replaceable.
d)
A relay is a electrically controlled set of contacts that are replaceable.
59.
Define a contactor.
a)
A contactor is a magnetically controlled set of contacts that may be rebuilt.
b)
A contactor is a electrically controlled set of contacts that may be rebuilt.
c)
A contactor is a magnetically controlled set of contacts that can not be rebuilt.
d)
A contactor is a electrically controlled set of contacts that can not be rebuilt.
60.
What causes the overload of a starter to open and disable the power circuit?
a)
This occurs because of the heat caused by excess current or ambient heat.
b)
This occurs because of the voltage caused by excess current or ambient heat.
c)
This occurs because of the heat caused by excess voltage or ambient heat.
d)
This occurs because of the heat caused by excess current or ambient cool.
61.
What effect would a loose connection have on a solder pot overload device?
a)
Heat produced by the loose connection can cause the solder pot to trip.
b)
Voltage produced by the loose connection can cause the solder pot to trip.
c)
Heat produced by the loose connection can cause the solder pot to heat.
d)
Voltage produced by the loose connection can cause the solder pot to heat.
62.
Most electrical problems with an electric motor are ____.
a)
short circuited windings. open windings, and grounded windings
b)
short circuited windings, closed windings, and grounded windings
c)
all of the above
d)
none of the above
63.
An open winding in an electric motor means that ____.
a)
a wire in a winding is broken
b)
the winding is making contact with the motor frame
c)
one winding is making contact with another winding
d)
the centrifugal switch to the start winding is open
64.
If the resistance of the run winding decreases, the ____.
a)
motor will draw too much current while it is running
b)
motor probably will not start
c)
centrifugal starting switch will not start the motor
d)
load on the motor is probably too great
65.
If a condenser fan motor grounds out, it will usually ____.
a)
trip a circuit breaker to shut off the unit
b)
keep running as the current is only going to ground
c)
run a little faster because the amperage draw will increase
d)
cause the evaporator to ice up
66.
A megger ____.
a)
measures very high resistances
b)
is an ammeter that can measure very small amounts of current
c)
is a digital voltmeter that measures very high resistances
d)
measures high voltage direct current
67.
If a motor hums but does not start, there is a potential problem ____.
a)
all of the above
b)
with the starting components
c)
with an open winding
d)
with insufficient supply voltage
68.
The wiring and connectors that carry the power to a motor must be in good condition. When a connection becomes loose, oxidation of the copper wire occurs. The oxidation ____.
a)
acts as an electrical resistance and causes the connection to heat more
b)
has no effect on the electrical connection
c)
decreases the resistance
d)
none of the above
69.
What is the best method to repair a fractional horsepower motor that has bad bearings?
a)
Replace the entire motor.
b)
Replace the bearings.
c)
Replace the bearings and shaft.
d)
Add a capacitor to the circuit for added torque.
70.
Belt tension will not have any affect on the wear of the bearings.
a)
False
b)
True
71.
Two common reasons for motor failure are improper pulley alignment and over-tightened belts.
a)
True
b)
False
72.
A motor has four leads out of it: two red and two black. The resistance between the red leads is 3 ohms. The resistance between the black leads is 5 ohms. The black leads are connected to the ____________________ winding.
a)
Start
b)
Run
c)
Common
d)
False
73.
The leads of an ohmmeter using the R x 100 scale are placed on the terminals of a capacitor and then reversed. The needle does not move. This would indicate that the capacitor is ____________________.
a)
Open
b)
Closed
c)
Neutral
d)
None of the above
74.
If the needle of an ohmmeter used to check a capacitor goes to the 0 ohms reading and does not move, this would indicate that the capacitor is ____________________.
a)
Shorted
b)
Open
c)
Closed
d)
Neutral
75.
How can a technician determine if a run capacitor has overheated?
a)
It has Swelled
b)
It is Cold
c)
It isHot
d)
It will Shrink
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