Michigan Fire Suppression System
Contractor Licensing Exam
1. A contractor is installing a wet pipe sprinkler system in a high-rise building in Detroit.
The system is required to have a fire pump. According to the Michigan Building Code
and NFPA 20, what is the primary reason the fire pump controller must be listed for the
specific type of pump motor (electric vs. diesel)?
A) To ensure the controller can step down the voltage for the building's lighting circuits.
B) To ensure the controller provides the appropriate starting method and overcurrent
protection for the motor's unique starting characteristics and locked rotor current.
C) To comply with the building owner's preference for a specific brand of electrical
panel.
D) To allow the fire alarm system to shut down the pump after 30 minutes of operation.
Rationale: The correct answer is B. Fire pump controllers are specifically engineered and
listed for the type of motor they serve. An electric motor has different starting current
(locked rotor) and running characteristics than a diesel engine. Using a non-listed
controller could result in failure to start, nuisance tripping, or catastrophic failure during
a fire. NFPA 20 mandates that controllers be listed and labeled for fire pump service.
Option A is incorrect because controllers do not step down voltage for other building
systems. Option C is irrelevant to code. Option D is false; fire pumps are designed to run
continuously until manually stopped or they fail, not to be shut down by the fire alarm
system.
2. During a final inspection of a new restaurant, the authority having jurisdiction (AHJ)
notes that the fire suppression system for the kitchen hood is a pre-engineered wet
chemical system. The contractor installed the system. What is the most critical
,requirement regarding the system's operation that the contractor must verify to pass
inspection?
A) The system must automatically shut down the electrical power to all kitchen
equipment, regardless of its proximity to the hood.
B) The system must be interconnected to the building's fire alarm system to initiate a
general evacuation.
C) The system must simultaneously shut off the fuel supply (gas or electric) to the
appliances under the hood and provide a visual indicator that the system has activated.
D) The system must be equipped with a manual pull station located at the main building
entrance for firefighter use.
Rationale: The correct answer is C. A pre-engineered wet chemical system's primary
function is to suppress a fire at the appliance. A critical safety interlock is the
simultaneous shutdown of fuel (gas or electric) to the appliances under the hood to
prevent reignition or fuel contribution to the fire. NFPA 17A requires this interlock.
Option A is too broad; it only requires equipment under the hood to be shut down.
Option B is not always a requirement unless local codes mandate it for commercial
kitchens. Option D is incorrect because the manual pull station is typically located at an
egress path from the kitchen area, not necessarily the main building entrance.
3. A contractor is bidding on a job to install a fire pump in an existing building. The
pump room is located on the first floor with the sole entrance from the exterior. What is
the minimum required fire-resistance rating for the walls and floor-ceiling assembly of
the pump room, assuming the building is not high-rise and the pump is for a sprinkler
system?
A) 1-hour
B) 2-hours
C) 3-hours
D) No fire-resistance rating is required if the room has a direct exterior entrance.
,Rationale: The correct answer is B. NFPA 20 requires fire pump rooms to be enclosed
with a 2-hour fire-resistance-rated construction. This is to protect the fire pump from a
fire occurring elsewhere in the building. While having a direct exterior entrance is
beneficial for firefighter access, it does not negate the requirement for the fire-resistive
enclosure. Option A (1-hour) is insufficient. Option C (3-hours) is typically for high-rise
building fire command centers. Option D is incorrect as it misinterprets the code.
4. You are a licensed contractor installing a dry pipe sprinkler system in an unheated
warehouse in the Upper Peninsula. After filling the system with air, you are performing a
trip test. What is the maximum allowable time from the opening of the inspector's test
valve until water flows from the inspector's test connection?
A) 30 seconds
B) 60 seconds
C) 90 seconds
D) 120 seconds
Rationale: The correct answer is B. NFPA 13 (2016 and later editions) requires that for a
dry pipe system, water must flow from the inspector’s test connection within 60 seconds
of the test valve being fully opened. This is to ensure that the system’s air pressure is
maintained correctly and the dry pipe valve will operate quickly enough to control a fire.
A time longer than 60 seconds indicates a potential issue with the air supply, valve size,
or system volume. Option A (30 seconds) is too restrictive. Option C (90 seconds) and D
(120 seconds) were acceptable in older editions but are no longer the current standard
for new installations.
5. A contractor is installing an underground fire main for a new industrial facility. The
pipe is ductile iron. What is the minimum depth of cover required below finished grade
to protect the pipe from damage, assuming the area is subject to light vehicular traffic
(e.g., parking lots)?
, A) 2 feet 6 inches (0.76 m)
B) 3 feet 0 inches (0.91 m)
C) 3 feet 6 inches (1.07 m)
D) 4 feet 0 inches (1.22 m)
Rationale: The correct answer is C. NFPA 24, Standard for the Installation of Private Fire
Service Mains, specifies minimum cover for underground piping. For areas subject to
light vehicular traffic, the minimum cover for ductile iron pipe is 3 feet 6 inches (1.07 m).
This depth is required to prevent mechanical damage from vehicle loads and also helps
protect against freezing in colder climates like Michigan. Option A is for non-vehicular
areas. Option B and D are incorrect per NFPA 24 tables.
6. A fire suppression contractor is hired to modify an existing wet pipe system to add
several new sprinklers. The existing system has a maximum operating pressure of 175
psi. The contractor installs new piping that is rated for 300 psi. What is the primary code
requirement regarding pressure ratings for the new pipe?
A) The new pipe must be rated for a minimum of 300 psi because it is a modification.
B) The new pipe must have a pressure rating that is at least equal to the maximum
system pressure the pipe may be subjected to.
C) The new pipe must be rated for 175 psi, but all fittings must be rated for 300 psi.
D) The pressure rating of the new pipe is irrelevant as long as it is the same material as
the existing pipe.
Rationale: The correct answer is B. NFPA 13 requires that all piping, valves, and fittings
in a sprinkler system be rated for the maximum potential system pressure they may
experience. While the existing system operates at 175 psi, a modification must not
introduce a weaker link. Using 300 psi rated pipe is acceptable and often done, but the
requirement is that the pipe’s rating meets or exceeds the system’s maximum pressure.
Option A is incorrect; there is no blanket requirement for 300 psi in modifications.
Contractor Licensing Exam
1. A contractor is installing a wet pipe sprinkler system in a high-rise building in Detroit.
The system is required to have a fire pump. According to the Michigan Building Code
and NFPA 20, what is the primary reason the fire pump controller must be listed for the
specific type of pump motor (electric vs. diesel)?
A) To ensure the controller can step down the voltage for the building's lighting circuits.
B) To ensure the controller provides the appropriate starting method and overcurrent
protection for the motor's unique starting characteristics and locked rotor current.
C) To comply with the building owner's preference for a specific brand of electrical
panel.
D) To allow the fire alarm system to shut down the pump after 30 minutes of operation.
Rationale: The correct answer is B. Fire pump controllers are specifically engineered and
listed for the type of motor they serve. An electric motor has different starting current
(locked rotor) and running characteristics than a diesel engine. Using a non-listed
controller could result in failure to start, nuisance tripping, or catastrophic failure during
a fire. NFPA 20 mandates that controllers be listed and labeled for fire pump service.
Option A is incorrect because controllers do not step down voltage for other building
systems. Option C is irrelevant to code. Option D is false; fire pumps are designed to run
continuously until manually stopped or they fail, not to be shut down by the fire alarm
system.
2. During a final inspection of a new restaurant, the authority having jurisdiction (AHJ)
notes that the fire suppression system for the kitchen hood is a pre-engineered wet
chemical system. The contractor installed the system. What is the most critical
,requirement regarding the system's operation that the contractor must verify to pass
inspection?
A) The system must automatically shut down the electrical power to all kitchen
equipment, regardless of its proximity to the hood.
B) The system must be interconnected to the building's fire alarm system to initiate a
general evacuation.
C) The system must simultaneously shut off the fuel supply (gas or electric) to the
appliances under the hood and provide a visual indicator that the system has activated.
D) The system must be equipped with a manual pull station located at the main building
entrance for firefighter use.
Rationale: The correct answer is C. A pre-engineered wet chemical system's primary
function is to suppress a fire at the appliance. A critical safety interlock is the
simultaneous shutdown of fuel (gas or electric) to the appliances under the hood to
prevent reignition or fuel contribution to the fire. NFPA 17A requires this interlock.
Option A is too broad; it only requires equipment under the hood to be shut down.
Option B is not always a requirement unless local codes mandate it for commercial
kitchens. Option D is incorrect because the manual pull station is typically located at an
egress path from the kitchen area, not necessarily the main building entrance.
3. A contractor is bidding on a job to install a fire pump in an existing building. The
pump room is located on the first floor with the sole entrance from the exterior. What is
the minimum required fire-resistance rating for the walls and floor-ceiling assembly of
the pump room, assuming the building is not high-rise and the pump is for a sprinkler
system?
A) 1-hour
B) 2-hours
C) 3-hours
D) No fire-resistance rating is required if the room has a direct exterior entrance.
,Rationale: The correct answer is B. NFPA 20 requires fire pump rooms to be enclosed
with a 2-hour fire-resistance-rated construction. This is to protect the fire pump from a
fire occurring elsewhere in the building. While having a direct exterior entrance is
beneficial for firefighter access, it does not negate the requirement for the fire-resistive
enclosure. Option A (1-hour) is insufficient. Option C (3-hours) is typically for high-rise
building fire command centers. Option D is incorrect as it misinterprets the code.
4. You are a licensed contractor installing a dry pipe sprinkler system in an unheated
warehouse in the Upper Peninsula. After filling the system with air, you are performing a
trip test. What is the maximum allowable time from the opening of the inspector's test
valve until water flows from the inspector's test connection?
A) 30 seconds
B) 60 seconds
C) 90 seconds
D) 120 seconds
Rationale: The correct answer is B. NFPA 13 (2016 and later editions) requires that for a
dry pipe system, water must flow from the inspector’s test connection within 60 seconds
of the test valve being fully opened. This is to ensure that the system’s air pressure is
maintained correctly and the dry pipe valve will operate quickly enough to control a fire.
A time longer than 60 seconds indicates a potential issue with the air supply, valve size,
or system volume. Option A (30 seconds) is too restrictive. Option C (90 seconds) and D
(120 seconds) were acceptable in older editions but are no longer the current standard
for new installations.
5. A contractor is installing an underground fire main for a new industrial facility. The
pipe is ductile iron. What is the minimum depth of cover required below finished grade
to protect the pipe from damage, assuming the area is subject to light vehicular traffic
(e.g., parking lots)?
, A) 2 feet 6 inches (0.76 m)
B) 3 feet 0 inches (0.91 m)
C) 3 feet 6 inches (1.07 m)
D) 4 feet 0 inches (1.22 m)
Rationale: The correct answer is C. NFPA 24, Standard for the Installation of Private Fire
Service Mains, specifies minimum cover for underground piping. For areas subject to
light vehicular traffic, the minimum cover for ductile iron pipe is 3 feet 6 inches (1.07 m).
This depth is required to prevent mechanical damage from vehicle loads and also helps
protect against freezing in colder climates like Michigan. Option A is for non-vehicular
areas. Option B and D are incorrect per NFPA 24 tables.
6. A fire suppression contractor is hired to modify an existing wet pipe system to add
several new sprinklers. The existing system has a maximum operating pressure of 175
psi. The contractor installs new piping that is rated for 300 psi. What is the primary code
requirement regarding pressure ratings for the new pipe?
A) The new pipe must be rated for a minimum of 300 psi because it is a modification.
B) The new pipe must have a pressure rating that is at least equal to the maximum
system pressure the pipe may be subjected to.
C) The new pipe must be rated for 175 psi, but all fittings must be rated for 300 psi.
D) The pressure rating of the new pipe is irrelevant as long as it is the same material as
the existing pipe.
Rationale: The correct answer is B. NFPA 13 requires that all piping, valves, and fittings
in a sprinkler system be rated for the maximum potential system pressure they may
experience. While the existing system operates at 175 psi, a modification must not
introduce a weaker link. Using 300 psi rated pipe is acceptable and often done, but the
requirement is that the pipe’s rating meets or exceeds the system’s maximum pressure.
Option A is incorrect; there is no blanket requirement for 300 psi in modifications.
