NFPA 110 Emergency Power Systems
Exam Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf.
1. According to NFPA 110, the primary purpose of an Emergency
Power Supply System (EPSS) is to:
A. Reduce facility electrical costs
B. Supply backup lighting only
C. Provide an alternate source of electrical power when the normal
source fails
D. Improve power quality during peak demand
Rationale: NFPA 110 defines an EPSS as a complete system that provides
an alternate source of electrical power when the normal source is
interrupted. The objective is to ensure continuity of critical operations
for life safety, essential business functions, or other designated loads.
2. Which of the following best describes a Level 1 EPSS?
A. A system serving nonessential equipment only
B. A system whose failure could result in loss of human life or serious
injury
,C. A portable generator used for temporary power
D. A system intended only for commercial convenience
Rationale: Level 1 systems are intended for applications where failure of
the emergency power supply could cause loss of life or severe injury.
Hospitals, emergency communications centers, and life safety systems
commonly require Level 1 EPSS installations.
3. Which EPSS classification is intended for applications where failure
is less critical to human safety?
A. Level 0
B. Level 2
C. Level 3
D. Level 4
Rationale: Level 2 systems are installed where interruption of power is
less critical and does not present an immediate threat to life safety.
These systems still require reliable operation but have less stringent
requirements than Level 1 systems.
4. The "Type" designation in NFPA 110 primarily refers to:
A. Generator fuel type
B. Maximum allowable time in seconds to restore power after loss of
the normal source
C. Number of transfer switches installed
D. Generator enclosure construction
,Rationale: The Type classification indicates the maximum acceptable
time between loss of normal power and availability of emergency
power. For example, Type 10 requires restoration of power within 10
seconds.
5. A Type 10 EPSS must restore power within:
A. 5 seconds
B. 10 seconds
C. 30 seconds
D. 60 seconds
Rationale: Type 10 systems are among the most common classifications
and must restore emergency power within 10 seconds following failure
of the normal electrical source.
6. Which component detects failure of the normal electrical source
and initiates generator starting?
A. Voltage regulator
B. Circuit breaker
C. Automatic transfer switch (ATS) sensing controls
D. Governor actuator
Rationale: The sensing circuitry within the automatic transfer switch
continuously monitors the normal source. Upon detecting unacceptable
voltage or frequency conditions, it initiates the generator start
sequence.
, 7. The primary function of an automatic transfer switch is to:
A. Increase generator output voltage
B. Synchronize utility generators
C. Transfer electrical loads between normal and emergency power
sources
D. Regulate generator engine speed
Rationale: The ATS safely transfers electrical loads from the normal
utility source to the emergency source and returns them after utility
power is restored and stabilized.
8. NFPA 110 requires routine exercising of generators primarily to:
A. Reduce fuel consumption
B. Extend battery warranty periods
C. Verify system readiness and identify deficiencies before an
emergency occurs
D. Increase generator horsepower
Rationale: Scheduled exercising confirms that the generator starts, runs,
and carries intended loads. Routine testing identifies maintenance needs
before actual emergencies occur.
9. Which fuel is commonly used for long-duration standby
emergency generators because of its storage stability?
A. Propane cylinders only
B. Diesel fuel
Exam Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf.
1. According to NFPA 110, the primary purpose of an Emergency
Power Supply System (EPSS) is to:
A. Reduce facility electrical costs
B. Supply backup lighting only
C. Provide an alternate source of electrical power when the normal
source fails
D. Improve power quality during peak demand
Rationale: NFPA 110 defines an EPSS as a complete system that provides
an alternate source of electrical power when the normal source is
interrupted. The objective is to ensure continuity of critical operations
for life safety, essential business functions, or other designated loads.
2. Which of the following best describes a Level 1 EPSS?
A. A system serving nonessential equipment only
B. A system whose failure could result in loss of human life or serious
injury
,C. A portable generator used for temporary power
D. A system intended only for commercial convenience
Rationale: Level 1 systems are intended for applications where failure of
the emergency power supply could cause loss of life or severe injury.
Hospitals, emergency communications centers, and life safety systems
commonly require Level 1 EPSS installations.
3. Which EPSS classification is intended for applications where failure
is less critical to human safety?
A. Level 0
B. Level 2
C. Level 3
D. Level 4
Rationale: Level 2 systems are installed where interruption of power is
less critical and does not present an immediate threat to life safety.
These systems still require reliable operation but have less stringent
requirements than Level 1 systems.
4. The "Type" designation in NFPA 110 primarily refers to:
A. Generator fuel type
B. Maximum allowable time in seconds to restore power after loss of
the normal source
C. Number of transfer switches installed
D. Generator enclosure construction
,Rationale: The Type classification indicates the maximum acceptable
time between loss of normal power and availability of emergency
power. For example, Type 10 requires restoration of power within 10
seconds.
5. A Type 10 EPSS must restore power within:
A. 5 seconds
B. 10 seconds
C. 30 seconds
D. 60 seconds
Rationale: Type 10 systems are among the most common classifications
and must restore emergency power within 10 seconds following failure
of the normal electrical source.
6. Which component detects failure of the normal electrical source
and initiates generator starting?
A. Voltage regulator
B. Circuit breaker
C. Automatic transfer switch (ATS) sensing controls
D. Governor actuator
Rationale: The sensing circuitry within the automatic transfer switch
continuously monitors the normal source. Upon detecting unacceptable
voltage or frequency conditions, it initiates the generator start
sequence.
, 7. The primary function of an automatic transfer switch is to:
A. Increase generator output voltage
B. Synchronize utility generators
C. Transfer electrical loads between normal and emergency power
sources
D. Regulate generator engine speed
Rationale: The ATS safely transfers electrical loads from the normal
utility source to the emergency source and returns them after utility
power is restored and stabilized.
8. NFPA 110 requires routine exercising of generators primarily to:
A. Reduce fuel consumption
B. Extend battery warranty periods
C. Verify system readiness and identify deficiencies before an
emergency occurs
D. Increase generator horsepower
Rationale: Scheduled exercising confirms that the generator starts, runs,
and carries intended loads. Routine testing identifies maintenance needs
before actual emergencies occur.
9. Which fuel is commonly used for long-duration standby
emergency generators because of its storage stability?
A. Propane cylinders only
B. Diesel fuel
