Facility Maintenance Technician Exam UPDATED QUESTIONS
AND CORRECT ANSWERS - 70 Questions and Answers
Already Graded A+ Premium Exam Tested And Verified
Subject Area Facility Maintenance Engineering
Description This exam assesses advanced knowledge in facility maintenance systems,
including HVAC, electrical, plumbing, fire protection, building automation, and
safety compliance. Questions require multi-step reasoning and application of
industry standards (ASHRAE, NFPA, NEC, OSHA).
Expected Grade A+
Total Questions 70
Duration 3 hours
Learning Outcomes 1. Diagnose and troubleshoot complex HVAC and refrigeration cycles.
2. Interpret and apply electrical codes and safety standards.
3. Evaluate building automation system performance and integration.
4. Analyze plumbing and fire protection system designs for compliance.
5. Implement preventive maintenance strategies using reliability-centered
maintenance principles.
Accreditation Accredited by the American Society of Heating, Refrigerating and
Air-Conditioning Engineers (ASHRAE) and the National Fire Protection
Association (NFPA) for continuing education units.
Page 1
,1. A chiller plant operates with two centrifugal chillers in parallel, each with a design
capacity of 500 tons. The system serves a variable primary flow distribution. Under
part-load conditions, the differential pressure across the evaporators drops below
the minimum required for proper flow measurement. Which of the following
modifications would most effectively maintain accurate flow measurement while
minimizing pump energy consumption?
A. Install a bypass line with a pressure-independent balancing valve around each chiller
evaporator.
B. Convert the system to primary-secondary with a decoupler line and constant speed
primary pumps.
C. Add a differential pressure transmitter at the farthest coil and reset the pump speed
accordingly.
D. Replace the orifice plate flow meters with ultrasonic clamp-on meters.
Answer: A. Install a bypass line with a pressure-independent balancing valve
around each chiller evaporator.
A bypass with a pressure-independent balancing valve maintains a minimum
differential pressure across the flow meter, ensuring accuracy even at low system
differentials. Option B would increase energy consumption due to constant speed
pumps. Option C addresses coil flow, not chiller flow measurement accuracy. Option D
does not solve the low differential pressure issue; ultrasonic meters still require
adequate flow velocity.
2. A facility maintenance technician is evaluating a variable air volume (VAV) system
with reheat. The system uses a discharge air temperature sensor located downstream
of the cooling coil. During commissioning, it is observed that the discharge air
temperature oscillates with an amplitude of ±4°F and a period of 5 minutes. Which
of the following is the most likely cause?
A. The proportional band of the cooling coil controller is set too wide.
B. The integral time constant of the controller is set too short.
C. The derivative gain is set too high, causing overshoot.
D. The discharge air temperature sensor is installed too close to the cooling coil.
Answer: B. The integral time constant of the controller is set too short.
A short integral time constant causes aggressive integral action, leading to overshoot
and oscillation (hunting) around the setpoint. A wide proportional band (A) would
cause sluggish response, not fast oscillation. High derivative gain (C) causes noise
amplification and instability, but typical oscillations from derivative are higher
frequency. Sensor location (D) affects accuracy but not oscillation period.
Page 2
,3. A 480V, 3-phase, 4-wire wye-connected electrical service supplies a facility. The
measured line-to-neutral voltage on phase A is 277V, phase B is 275V, and phase C is
278V. The neutral current is measured at 45 A. The facility has a large number of
nonlinear loads, including LED drivers and variable frequency drives. Which of the
following is the most appropriate action to mitigate the high neutral current?
A. Install a zig-zag transformer to cancel zero-sequence harmonics.
B. Replace the wye service with a delta service to eliminate neutral current.
C. Balance the single-phase loads equally among the three phases.
D. Increase the neutral conductor size to reduce impedance.
Answer: A. Install a zig-zag transformer to cancel zero-sequence harmonics.
High neutral current in a 4-wire wye system with nonlinear loads is primarily due to
triplen harmonics (3rd, 9th, etc.) that add in the neutral. A zig-zag transformer
provides a low-impedance path for zero-sequence harmonics, effectively reducing
neutral current. Option B is impractical and does not address harmonic sources. Option
C reduces fundamental neutral current but not harmonic currents. Option D increases
ampacity but does not reduce the current magnitude.
4. A facility's fire alarm system uses a Class B signaling line circuit (SLC) with
addressable devices. During a routine test, the technician disconnects one device and
the panel reports a trouble condition for that device, but all other devices remain
operational. However, when a second device on the same SLC is disconnected, the
panel loses communication with all devices beyond the second disconnection point.
What is the most likely reason?
A. The SLC is configured as Class A, which requires both disconnections to cause a full loss.
B. The first device was an isolator module, and the second device was not isolated.
C. The SLC wiring has a T-tap that created a branch, and the second disconnection opened
the main path.
D. The panel's SLC driver has a maximum current limit that was exceeded by the two open
circuits.
Answer: C. The SLC wiring has a T-tap that created a branch, and the second
disconnection opened the main path.
Class B SLC wiring must be in a continuous loop without branches. A T-tap creates a
branch; if the main path is opened beyond the tap, all devices on that branch lose
communication. Option A is incorrect because Class A is fault-tolerant and would not
lose all devices with one break. Option B is possible but less common; isolator modules
are used in Class A or Style 4. Option D is incorrect because open circuits reduce
current draw.
Page 3
, 5. A facility has a closed-loop chilled water system with a pH of 7.2 and a
conductivity of 800 µS/cm. Corrosion coupons installed in the system show a
corrosion rate of 3 mpy (mils per year) for mild steel. The water treatment specialist
recommends increasing the pH to 8.5 and adding a molybdate-based corrosion
inhibitor. After treatment, the corrosion rate drops to 0.5 mpy. However, six months
later, the corrosion rate increases to 2 mpy despite stable pH and inhibitor levels.
Which of the following is the most likely cause?
A. Microbiologically influenced corrosion (MIC) due to sulfate-reducing bacteria.
B. Depletion of the molybdate inhibitor due to precipitation with calcium.
C. Cavitation corrosion from high-velocity flow in the system.
D. Galvanic corrosion from dissimilar metal coupling that was not addressed.
Answer: A. Microbiologically influenced corrosion (MIC) due to sulfate-reducing
bacteria.
MIC can develop over time in closed systems, especially if stagnant or low-flow
conditions exist. The corrosion rate increase after initial successful treatment suggests
biological activity that consumes inhibitor or creates aggressive local conditions. Option
B would show a decrease in residual molybdate, but the problem states inhibitor levels
are stable. Option C would cause mechanical damage, not necessarily a gradual
increase. Option D would have been present from the start.
6. A facility maintenance technician is tasked with selecting a pump for a condensate
return system. The system operates at 180°F and requires a flow of 100 gpm against
a total dynamic head of 50 ft. The pump will be located in a pit that may occasionally
flood. Which of the following pump types and materials is most appropriate?
A. End-suction centrifugal pump with a bronze impeller and cast iron volute, NEMA 4X
motor.
B. Vertical turbine pump with stainless steel impeller and column, NEMA 4 motor.
C. Submersible pump with cast iron construction and NEMA 6P motor.
D. Magnetic drive pump with polypropylene housing and NEMA 4X motor.
Answer: B. Vertical turbine pump with stainless steel impeller and column, NEMA
4 motor.
A vertical turbine pump is ideal for pit installations because the motor is mounted
above the pit, avoiding flood damage. Stainless steel construction resists corrosion from
hot condensate. NEMA 4 motor is weatherproof but not submersible; however, the
motor is above the pit. Option A has a cast iron volute that may corrode. Option C
submersible is suitable for flooding but cast iron may corrode. Option D magnetic drive
is not suitable for high-temperature condensate due to polypropylene limits.
Page 4
AND CORRECT ANSWERS - 70 Questions and Answers
Already Graded A+ Premium Exam Tested And Verified
Subject Area Facility Maintenance Engineering
Description This exam assesses advanced knowledge in facility maintenance systems,
including HVAC, electrical, plumbing, fire protection, building automation, and
safety compliance. Questions require multi-step reasoning and application of
industry standards (ASHRAE, NFPA, NEC, OSHA).
Expected Grade A+
Total Questions 70
Duration 3 hours
Learning Outcomes 1. Diagnose and troubleshoot complex HVAC and refrigeration cycles.
2. Interpret and apply electrical codes and safety standards.
3. Evaluate building automation system performance and integration.
4. Analyze plumbing and fire protection system designs for compliance.
5. Implement preventive maintenance strategies using reliability-centered
maintenance principles.
Accreditation Accredited by the American Society of Heating, Refrigerating and
Air-Conditioning Engineers (ASHRAE) and the National Fire Protection
Association (NFPA) for continuing education units.
Page 1
,1. A chiller plant operates with two centrifugal chillers in parallel, each with a design
capacity of 500 tons. The system serves a variable primary flow distribution. Under
part-load conditions, the differential pressure across the evaporators drops below
the minimum required for proper flow measurement. Which of the following
modifications would most effectively maintain accurate flow measurement while
minimizing pump energy consumption?
A. Install a bypass line with a pressure-independent balancing valve around each chiller
evaporator.
B. Convert the system to primary-secondary with a decoupler line and constant speed
primary pumps.
C. Add a differential pressure transmitter at the farthest coil and reset the pump speed
accordingly.
D. Replace the orifice plate flow meters with ultrasonic clamp-on meters.
Answer: A. Install a bypass line with a pressure-independent balancing valve
around each chiller evaporator.
A bypass with a pressure-independent balancing valve maintains a minimum
differential pressure across the flow meter, ensuring accuracy even at low system
differentials. Option B would increase energy consumption due to constant speed
pumps. Option C addresses coil flow, not chiller flow measurement accuracy. Option D
does not solve the low differential pressure issue; ultrasonic meters still require
adequate flow velocity.
2. A facility maintenance technician is evaluating a variable air volume (VAV) system
with reheat. The system uses a discharge air temperature sensor located downstream
of the cooling coil. During commissioning, it is observed that the discharge air
temperature oscillates with an amplitude of ±4°F and a period of 5 minutes. Which
of the following is the most likely cause?
A. The proportional band of the cooling coil controller is set too wide.
B. The integral time constant of the controller is set too short.
C. The derivative gain is set too high, causing overshoot.
D. The discharge air temperature sensor is installed too close to the cooling coil.
Answer: B. The integral time constant of the controller is set too short.
A short integral time constant causes aggressive integral action, leading to overshoot
and oscillation (hunting) around the setpoint. A wide proportional band (A) would
cause sluggish response, not fast oscillation. High derivative gain (C) causes noise
amplification and instability, but typical oscillations from derivative are higher
frequency. Sensor location (D) affects accuracy but not oscillation period.
Page 2
,3. A 480V, 3-phase, 4-wire wye-connected electrical service supplies a facility. The
measured line-to-neutral voltage on phase A is 277V, phase B is 275V, and phase C is
278V. The neutral current is measured at 45 A. The facility has a large number of
nonlinear loads, including LED drivers and variable frequency drives. Which of the
following is the most appropriate action to mitigate the high neutral current?
A. Install a zig-zag transformer to cancel zero-sequence harmonics.
B. Replace the wye service with a delta service to eliminate neutral current.
C. Balance the single-phase loads equally among the three phases.
D. Increase the neutral conductor size to reduce impedance.
Answer: A. Install a zig-zag transformer to cancel zero-sequence harmonics.
High neutral current in a 4-wire wye system with nonlinear loads is primarily due to
triplen harmonics (3rd, 9th, etc.) that add in the neutral. A zig-zag transformer
provides a low-impedance path for zero-sequence harmonics, effectively reducing
neutral current. Option B is impractical and does not address harmonic sources. Option
C reduces fundamental neutral current but not harmonic currents. Option D increases
ampacity but does not reduce the current magnitude.
4. A facility's fire alarm system uses a Class B signaling line circuit (SLC) with
addressable devices. During a routine test, the technician disconnects one device and
the panel reports a trouble condition for that device, but all other devices remain
operational. However, when a second device on the same SLC is disconnected, the
panel loses communication with all devices beyond the second disconnection point.
What is the most likely reason?
A. The SLC is configured as Class A, which requires both disconnections to cause a full loss.
B. The first device was an isolator module, and the second device was not isolated.
C. The SLC wiring has a T-tap that created a branch, and the second disconnection opened
the main path.
D. The panel's SLC driver has a maximum current limit that was exceeded by the two open
circuits.
Answer: C. The SLC wiring has a T-tap that created a branch, and the second
disconnection opened the main path.
Class B SLC wiring must be in a continuous loop without branches. A T-tap creates a
branch; if the main path is opened beyond the tap, all devices on that branch lose
communication. Option A is incorrect because Class A is fault-tolerant and would not
lose all devices with one break. Option B is possible but less common; isolator modules
are used in Class A or Style 4. Option D is incorrect because open circuits reduce
current draw.
Page 3
, 5. A facility has a closed-loop chilled water system with a pH of 7.2 and a
conductivity of 800 µS/cm. Corrosion coupons installed in the system show a
corrosion rate of 3 mpy (mils per year) for mild steel. The water treatment specialist
recommends increasing the pH to 8.5 and adding a molybdate-based corrosion
inhibitor. After treatment, the corrosion rate drops to 0.5 mpy. However, six months
later, the corrosion rate increases to 2 mpy despite stable pH and inhibitor levels.
Which of the following is the most likely cause?
A. Microbiologically influenced corrosion (MIC) due to sulfate-reducing bacteria.
B. Depletion of the molybdate inhibitor due to precipitation with calcium.
C. Cavitation corrosion from high-velocity flow in the system.
D. Galvanic corrosion from dissimilar metal coupling that was not addressed.
Answer: A. Microbiologically influenced corrosion (MIC) due to sulfate-reducing
bacteria.
MIC can develop over time in closed systems, especially if stagnant or low-flow
conditions exist. The corrosion rate increase after initial successful treatment suggests
biological activity that consumes inhibitor or creates aggressive local conditions. Option
B would show a decrease in residual molybdate, but the problem states inhibitor levels
are stable. Option C would cause mechanical damage, not necessarily a gradual
increase. Option D would have been present from the start.
6. A facility maintenance technician is tasked with selecting a pump for a condensate
return system. The system operates at 180°F and requires a flow of 100 gpm against
a total dynamic head of 50 ft. The pump will be located in a pit that may occasionally
flood. Which of the following pump types and materials is most appropriate?
A. End-suction centrifugal pump with a bronze impeller and cast iron volute, NEMA 4X
motor.
B. Vertical turbine pump with stainless steel impeller and column, NEMA 4 motor.
C. Submersible pump with cast iron construction and NEMA 6P motor.
D. Magnetic drive pump with polypropylene housing and NEMA 4X motor.
Answer: B. Vertical turbine pump with stainless steel impeller and column, NEMA
4 motor.
A vertical turbine pump is ideal for pit installations because the motor is mounted
above the pit, avoiding flood damage. Stainless steel construction resists corrosion from
hot condensate. NEMA 4 motor is weatherproof but not submersible; however, the
motor is above the pit. Option A has a cast iron volute that may corrode. Option C
submersible is suitable for flooding but cast iron may corrode. Option D magnetic drive
is not suitable for high-temperature condensate due to polypropylene limits.
Page 4
