LADWP ELECTRIC STATION OPERATOR
EXAM — CLASS 5224 WITH QUESTIONS AND
VERIFIED ANSWERS, PLUS DETAILED
RATIONALES/EXPERT VERIFIED FOR
GUARANTEED PASS 2026/LATEST
UPDATE/INSTANT DOWNLOAD PDF
1. An Electric Station Operator is preparing to perform a switching
sequence on a high-voltage circuit. Before operating the first
switching device, the operator reviews the approved switching
order, identifies the equipment by designation, and confirms the
intended electrical configuration. What is the primary reason for
following the switching procedure in the exact prescribed sequence?
A. To reduce the amount of reactive power consumed by the station
B. To ensure equipment is operated in a controlled sequence that
prevents unsafe conditions and unintended system configurations
C. To increase the interrupting rating of the circuit breakers involved
D. To eliminate the need for communication with the system dispatcher
Answer: B. To ensure equipment is operated in a controlled
sequence that prevents unsafe conditions and unintended system
configurations
Rationale: A switching procedure is fundamentally a safety and
system-control document. Each step is sequenced so that equipment is
not energized, de-energized, isolated, grounded, or placed in service
under an unsafe configuration. A seemingly harmless change can
create backfeed, paralleling, excessive loading, an inadvertent
energization, or an unsafe condition for personnel. Reactive power,
breaker interrupting capability, and communication requirements are
1
,separate considerations and are not reasons to bypass the prescribed
sequence.
2. A circuit breaker is rated to interrupt fault current, while a
nearby disconnect switch is not intended to interrupt a significant
fault current. Under normal station operating practice, what is the
most important distinction between these two devices?
A. The disconnect switch changes frequency while the breaker changes
voltage
B. The disconnect switch provides isolation, while the circuit breaker is
designed to interrupt normal and abnormal current within its ratings
C. The circuit breaker provides mechanical isolation only, while the
disconnect switch clears faults automatically
D. Both devices have identical interrupting functions but different
operating handles
Answer: B. The disconnect switch provides isolation, while the
circuit breaker is designed to interrupt normal and abnormal
current within its ratings
Rationale: A circuit breaker is specifically designed to make, carry,
and interrupt current, including fault current within its interrupting
capability. A disconnect or isolating switch is primarily used to
establish a visible or defined isolation point and generally should not
be used to interrupt load or fault current unless specifically designed
and authorized for that purpose. Confusing these functions can result
in severe arcing, equipment damage, or personnel injury.
3. A station operator is told that a transformer is being removed
from service for maintenance. The operator sees that the
transformer circuit breaker has opened but the transformer
2
,terminals remain connected through closed disconnect switches.
What should the operator understand about this condition?
A. The transformer is automatically considered grounded
B. The transformer is isolated and safe because the breaker is open
C. The transformer may still be electrically connected to portions of the
system and requires appropriate isolation before work authorization
D. The transformer has been permanently removed from the electrical
system
Answer: C. The transformer may still be electrically connected to
portions of the system and requires appropriate isolation before
work authorization
Rationale: Opening a circuit breaker does not necessarily establish all
required isolation points. A transformer may remain connected to an
energized source through another circuit, bus, auxiliary connection,
backfeed path, or closed disconnect. Proper clearance procedures
require identification and verification of all possible sources and
establishment of the prescribed isolation and grounding conditions.
4. A 13.8-kV three-phase system has a line-to-line voltage of 13.8 kV.
Approximately what is the line-to-neutral voltage of a balanced wye-
connected system?
A. 3.98 kV
B. 7.97 kV
C. 13.8 kV
D. 23.9 kV
Answer: B. 7.97 kV
Rationale: For a balanced wye-connected three-phase system, line-to-
neutral voltage equals line-to-line voltage divided by √3. Thus, 13.8 kV
÷ 1.732 ≈ 7.97 kV. Recognizing the distinction between line-to-line and
3
, line-to-neutral voltage is essential when interpreting station meters,
transformer connections, and system diagrams.
5. A 60-Hz generator is operating at a stable frequency, but the
station operator observes that the generator terminal voltage is
decreasing while real-power output remains relatively constant.
Which generator control is most directly associated with terminal
voltage and reactive-power behavior?
A. Prime-mover governor
B. Excitation system
C. Mechanical brake
D. Speed-sensing tachometer only
Answer: B. Excitation system
Rationale: The excitation system controls the generator's field strength
and has a major influence on terminal voltage and reactive-power
output. The governor primarily regulates mechanical input and
therefore real-power production and frequency response. Increasing
or decreasing excitation should not be confused with controlling
generator speed or real-power output.
6. A load consumes 80 MVA at a power factor of 0.80 lagging.
Approximately how much real power is being delivered to the load?
A. 48 MW
B. 64 MW
C. 80 MW
D. 100 MW
Answer: B. 64 MW
4
EXAM — CLASS 5224 WITH QUESTIONS AND
VERIFIED ANSWERS, PLUS DETAILED
RATIONALES/EXPERT VERIFIED FOR
GUARANTEED PASS 2026/LATEST
UPDATE/INSTANT DOWNLOAD PDF
1. An Electric Station Operator is preparing to perform a switching
sequence on a high-voltage circuit. Before operating the first
switching device, the operator reviews the approved switching
order, identifies the equipment by designation, and confirms the
intended electrical configuration. What is the primary reason for
following the switching procedure in the exact prescribed sequence?
A. To reduce the amount of reactive power consumed by the station
B. To ensure equipment is operated in a controlled sequence that
prevents unsafe conditions and unintended system configurations
C. To increase the interrupting rating of the circuit breakers involved
D. To eliminate the need for communication with the system dispatcher
Answer: B. To ensure equipment is operated in a controlled
sequence that prevents unsafe conditions and unintended system
configurations
Rationale: A switching procedure is fundamentally a safety and
system-control document. Each step is sequenced so that equipment is
not energized, de-energized, isolated, grounded, or placed in service
under an unsafe configuration. A seemingly harmless change can
create backfeed, paralleling, excessive loading, an inadvertent
energization, or an unsafe condition for personnel. Reactive power,
breaker interrupting capability, and communication requirements are
1
,separate considerations and are not reasons to bypass the prescribed
sequence.
2. A circuit breaker is rated to interrupt fault current, while a
nearby disconnect switch is not intended to interrupt a significant
fault current. Under normal station operating practice, what is the
most important distinction between these two devices?
A. The disconnect switch changes frequency while the breaker changes
voltage
B. The disconnect switch provides isolation, while the circuit breaker is
designed to interrupt normal and abnormal current within its ratings
C. The circuit breaker provides mechanical isolation only, while the
disconnect switch clears faults automatically
D. Both devices have identical interrupting functions but different
operating handles
Answer: B. The disconnect switch provides isolation, while the
circuit breaker is designed to interrupt normal and abnormal
current within its ratings
Rationale: A circuit breaker is specifically designed to make, carry,
and interrupt current, including fault current within its interrupting
capability. A disconnect or isolating switch is primarily used to
establish a visible or defined isolation point and generally should not
be used to interrupt load or fault current unless specifically designed
and authorized for that purpose. Confusing these functions can result
in severe arcing, equipment damage, or personnel injury.
3. A station operator is told that a transformer is being removed
from service for maintenance. The operator sees that the
transformer circuit breaker has opened but the transformer
2
,terminals remain connected through closed disconnect switches.
What should the operator understand about this condition?
A. The transformer is automatically considered grounded
B. The transformer is isolated and safe because the breaker is open
C. The transformer may still be electrically connected to portions of the
system and requires appropriate isolation before work authorization
D. The transformer has been permanently removed from the electrical
system
Answer: C. The transformer may still be electrically connected to
portions of the system and requires appropriate isolation before
work authorization
Rationale: Opening a circuit breaker does not necessarily establish all
required isolation points. A transformer may remain connected to an
energized source through another circuit, bus, auxiliary connection,
backfeed path, or closed disconnect. Proper clearance procedures
require identification and verification of all possible sources and
establishment of the prescribed isolation and grounding conditions.
4. A 13.8-kV three-phase system has a line-to-line voltage of 13.8 kV.
Approximately what is the line-to-neutral voltage of a balanced wye-
connected system?
A. 3.98 kV
B. 7.97 kV
C. 13.8 kV
D. 23.9 kV
Answer: B. 7.97 kV
Rationale: For a balanced wye-connected three-phase system, line-to-
neutral voltage equals line-to-line voltage divided by √3. Thus, 13.8 kV
÷ 1.732 ≈ 7.97 kV. Recognizing the distinction between line-to-line and
3
, line-to-neutral voltage is essential when interpreting station meters,
transformer connections, and system diagrams.
5. A 60-Hz generator is operating at a stable frequency, but the
station operator observes that the generator terminal voltage is
decreasing while real-power output remains relatively constant.
Which generator control is most directly associated with terminal
voltage and reactive-power behavior?
A. Prime-mover governor
B. Excitation system
C. Mechanical brake
D. Speed-sensing tachometer only
Answer: B. Excitation system
Rationale: The excitation system controls the generator's field strength
and has a major influence on terminal voltage and reactive-power
output. The governor primarily regulates mechanical input and
therefore real-power production and frequency response. Increasing
or decreasing excitation should not be confused with controlling
generator speed or real-power output.
6. A load consumes 80 MVA at a power factor of 0.80 lagging.
Approximately how much real power is being delivered to the load?
A. 48 MW
B. 64 MW
C. 80 MW
D. 100 MW
Answer: B. 64 MW
4
