TEXAS SINGLEPHASE PUMP EXAM
COMPLETE QUESTIONS AND
DETAILED SOLUTIONS LATEST
UPDATE THIS YEAR-JUST RELEASED
Question 1
A technician measures 240 volts at a single-phase pump
motor, but the motor only hums loudly without rotating.
Which condition is MOST likely causing this problem?
A. Open grounding conductor
B. Failed start capacitor
C. Excessive water pressure
D. Oversized pressure tank
Answer: B. Failed start capacitor
Rationale:
Single-phase motors commonly rely on a start capacitor to
create starting torque. When the capacitor fails, the motor
often hums because the run winding energizes without
sufficient starting torque to rotate the shaft.
Question 2
,A centrifugal pump repeatedly loses prime after shutting
off overnight in a residential well system. Which
component failure is MOST likely responsible?
A. Thermal overload protector
B. Grounding electrode conductor
C. Check valve leakage
D. Pressure gauge blockage
Answer: C. Check valve leakage
Rationale:
A leaking check valve allows water to drain backward,
causing the pump to lose prime. Centrifugal and jet pumps
require retained water within the suction line for proper
startup.
Question 3
During troubleshooting, a pump motor repeatedly trips its
breaker immediately after startup. Which condition
should be checked FIRST?
A. Water tank color
B. Locked rotor condition
C. Pressure switch calibration sticker
D. Pipe insulation thickness
Answer: B. Locked rotor condition
,Rationale:
A locked rotor draws extremely high inrush current,
frequently causing breaker trips. Mechanical seizure,
bearing failure, or jammed impellers commonly create this
condition.
Question 4
A technician installs undersized conductors on a long-
distance pump circuit. What is the MOST likely
operational consequence?
A. Increased pump efficiency
B. Lower starting current
C. Excessive voltage drop
D. Reduced grounding resistance
Answer: C. Excessive voltage drop
Rationale:
Undersized conductors increase resistance, causing voltage
drop. Motors operating under low voltage may overheat,
draw excessive current, and experience shortened service
life.
Question 5
, Which NEC article primarily governs motor installations
and motor branch-circuit protection requirements?
A. Article 250
B. Article 430
C. Article 310
D. Article 680
Answer: B. Article 430
Rationale:
NEC Article 430 specifically covers motors, motor circuits,
controllers, disconnects, overload protection, and branch-
circuit short-circuit protection.
Question 6
A pump system short cycles rapidly between start and
stop conditions. Which issue is MOST likely responsible?
A. Oversized grounding conductor
B. Waterlogged pressure tank
C. Excessive conduit support spacing
D. Low branch-circuit resistance
Answer: B. Waterlogged pressure tank
Rationale:
A waterlogged pressure tank lacks adequate air cushion,
COMPLETE QUESTIONS AND
DETAILED SOLUTIONS LATEST
UPDATE THIS YEAR-JUST RELEASED
Question 1
A technician measures 240 volts at a single-phase pump
motor, but the motor only hums loudly without rotating.
Which condition is MOST likely causing this problem?
A. Open grounding conductor
B. Failed start capacitor
C. Excessive water pressure
D. Oversized pressure tank
Answer: B. Failed start capacitor
Rationale:
Single-phase motors commonly rely on a start capacitor to
create starting torque. When the capacitor fails, the motor
often hums because the run winding energizes without
sufficient starting torque to rotate the shaft.
Question 2
,A centrifugal pump repeatedly loses prime after shutting
off overnight in a residential well system. Which
component failure is MOST likely responsible?
A. Thermal overload protector
B. Grounding electrode conductor
C. Check valve leakage
D. Pressure gauge blockage
Answer: C. Check valve leakage
Rationale:
A leaking check valve allows water to drain backward,
causing the pump to lose prime. Centrifugal and jet pumps
require retained water within the suction line for proper
startup.
Question 3
During troubleshooting, a pump motor repeatedly trips its
breaker immediately after startup. Which condition
should be checked FIRST?
A. Water tank color
B. Locked rotor condition
C. Pressure switch calibration sticker
D. Pipe insulation thickness
Answer: B. Locked rotor condition
,Rationale:
A locked rotor draws extremely high inrush current,
frequently causing breaker trips. Mechanical seizure,
bearing failure, or jammed impellers commonly create this
condition.
Question 4
A technician installs undersized conductors on a long-
distance pump circuit. What is the MOST likely
operational consequence?
A. Increased pump efficiency
B. Lower starting current
C. Excessive voltage drop
D. Reduced grounding resistance
Answer: C. Excessive voltage drop
Rationale:
Undersized conductors increase resistance, causing voltage
drop. Motors operating under low voltage may overheat,
draw excessive current, and experience shortened service
life.
Question 5
, Which NEC article primarily governs motor installations
and motor branch-circuit protection requirements?
A. Article 250
B. Article 430
C. Article 310
D. Article 680
Answer: B. Article 430
Rationale:
NEC Article 430 specifically covers motors, motor circuits,
controllers, disconnects, overload protection, and branch-
circuit short-circuit protection.
Question 6
A pump system short cycles rapidly between start and
stop conditions. Which issue is MOST likely responsible?
A. Oversized grounding conductor
B. Waterlogged pressure tank
C. Excessive conduit support spacing
D. Low branch-circuit resistance
Answer: B. Waterlogged pressure tank
Rationale:
A waterlogged pressure tank lacks adequate air cushion,
