TPC DEVELOPING ELECTRICAL TROUBLESHOOTING
The actual location and routing of circuits is shown on a - Answer -wiring diagram
A power-installation drawing shows - Answer -only power outlets
Changing the number of magnetic poles in the stator of a squirrel-cage motor permits
the motor to run - Answer -two or more fixed speeds
Most reversing starters with low-voltage remote pushbuttons are all of the following
EXCEPT - Answer -mechanically interconnected
Deterioration in a selenium rectifier is indicated by - Answer -a gradual rise in the input
current
In autotransformer input circuits, each input line should be - Answer -fused
Which of the following is NOT a common cause of mechanical vibration? - Answer -
Worn brushes
Overvoltage, excessive current and too-frequent operation are possible causes of -
Answer -burned or short-circuited magnet coils
A relay that has "dogs" located directly above the operating bar is called a
____________ relay - Answer -latching
Which are most affected by overvoltage? - Answer -Slow-speed motors(not sure)
If a motor stops for no apparent reason and you are called to inspect the motor starter,
the first thing you should check is the - Answer -trip levers on the thermal overload
relays
NEMA recommends seasoning linear lamps for _____ hr before dimming - Answer -12
The color temperature of the light produced by a lamp is expressed in degrees -
Answer -Kelvin
Mechanical linkages of motor contacts, relays, and solenoids on new equipment should
- Answer -move freely when the machine is turned on
In the identification 8TR15XTO, the X indicates - Answer -normally closed
Thermal overload relays can generally be reset after cooling for about - Answer -1
minute
, One added feature of newer motor starters is a single-phase sensor that detects -
Answer -current unbalance
A circuit that provides undervoltage release and has two wires connected to the pilot
device that energizes the magnetic control circuit is said to have - Answer -two-wire
control
The ____________ contacts on a motor starter provide a parallel path for the current to
the coil - Answer -auxiliary
Most methods of reducing motor speed when using multispeed controllers involve the
operator - Answer -pressing the STOP button
All of the following are common reasons why a split-phase motor makes a noticeable
noise when operating, EXCEPT - Answer -too little end play
On an electrical diagram, a control relay is indicated by the designation - Answer -CR
The ____________ circuit of an electrical schematic is the simplest part of the diagram
and the easiest to follow. - Answer -power
Mixing brush grades in a dc motor causes - Answer -unequal load distribution among
brushes
A film of oil on the commutator does all of the following EXCEPT - Answer -prolong
brush life
Operating a heavily loaded motor at __________ can cause a high slip - Answer -
reduced voltage
Adding limit switches to the control circuit of a reversing motor provides - Answer -
overtravel protection
On a reversing starter, mechanical interlocks are used to prevent both sets of three-
phase contacts from being operated at the same time. The closing of ____________
operates a mechanism that prevents the closing of the opposite contactor. - Answer -
one contactor
Which of the following is not typically used to identify conductors in a motor-control
circuit? - Answer -Colors
The NEC requires a fuse to be installed in all __________ conductors - Answer -
ungrounded
A sequence of operation - Answer -is used with an elementary diagram
The actual location and routing of circuits is shown on a - Answer -wiring diagram
A power-installation drawing shows - Answer -only power outlets
Changing the number of magnetic poles in the stator of a squirrel-cage motor permits
the motor to run - Answer -two or more fixed speeds
Most reversing starters with low-voltage remote pushbuttons are all of the following
EXCEPT - Answer -mechanically interconnected
Deterioration in a selenium rectifier is indicated by - Answer -a gradual rise in the input
current
In autotransformer input circuits, each input line should be - Answer -fused
Which of the following is NOT a common cause of mechanical vibration? - Answer -
Worn brushes
Overvoltage, excessive current and too-frequent operation are possible causes of -
Answer -burned or short-circuited magnet coils
A relay that has "dogs" located directly above the operating bar is called a
____________ relay - Answer -latching
Which are most affected by overvoltage? - Answer -Slow-speed motors(not sure)
If a motor stops for no apparent reason and you are called to inspect the motor starter,
the first thing you should check is the - Answer -trip levers on the thermal overload
relays
NEMA recommends seasoning linear lamps for _____ hr before dimming - Answer -12
The color temperature of the light produced by a lamp is expressed in degrees -
Answer -Kelvin
Mechanical linkages of motor contacts, relays, and solenoids on new equipment should
- Answer -move freely when the machine is turned on
In the identification 8TR15XTO, the X indicates - Answer -normally closed
Thermal overload relays can generally be reset after cooling for about - Answer -1
minute
, One added feature of newer motor starters is a single-phase sensor that detects -
Answer -current unbalance
A circuit that provides undervoltage release and has two wires connected to the pilot
device that energizes the magnetic control circuit is said to have - Answer -two-wire
control
The ____________ contacts on a motor starter provide a parallel path for the current to
the coil - Answer -auxiliary
Most methods of reducing motor speed when using multispeed controllers involve the
operator - Answer -pressing the STOP button
All of the following are common reasons why a split-phase motor makes a noticeable
noise when operating, EXCEPT - Answer -too little end play
On an electrical diagram, a control relay is indicated by the designation - Answer -CR
The ____________ circuit of an electrical schematic is the simplest part of the diagram
and the easiest to follow. - Answer -power
Mixing brush grades in a dc motor causes - Answer -unequal load distribution among
brushes
A film of oil on the commutator does all of the following EXCEPT - Answer -prolong
brush life
Operating a heavily loaded motor at __________ can cause a high slip - Answer -
reduced voltage
Adding limit switches to the control circuit of a reversing motor provides - Answer -
overtravel protection
On a reversing starter, mechanical interlocks are used to prevent both sets of three-
phase contacts from being operated at the same time. The closing of ____________
operates a mechanism that prevents the closing of the opposite contactor. - Answer -
one contactor
Which of the following is not typically used to identify conductors in a motor-control
circuit? - Answer -Colors
The NEC requires a fuse to be installed in all __________ conductors - Answer -
ungrounded
A sequence of operation - Answer -is used with an elementary diagram
