NICET Electrical Power Testing
Certification Exam Questions and
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf.
Question 1
A technician is performing insulation resistance testing on a de-
energized medium-voltage cable. Which instrument is most appropriate
for this task?
A. Digital multimeter
B. Clamp-on ammeter
C. Megohmmeter (Insulation Resistance Tester)
D. Oscilloscope
Rationale: A megohmmeter applies a high DC voltage (commonly 500 V,
1 kV, 2.5 kV, or 5 kV depending on the equipment) to measure insulation
resistance. It is specifically designed to detect insulation deterioration,
moisture contamination, and leakage paths. A standard multimeter
cannot adequately test insulation integrity because it applies only a low
test voltage.
,Question 2
Before conducting any electrical power testing on energized equipment,
the technician's highest priority is to:
A. Verify equipment age
B. Review previous maintenance records
C. Follow lockout/tagout procedures and applicable electrical safety
requirements
D. Clean all testing instruments
Rationale: Personnel safety is always the first priority. Lockout/tagout
(LOTO), verification of absence of voltage, proper PPE selection, and
compliance with NFPA 70E and OSHA requirements help prevent
electrical shock, arc flash, and equipment damage during testing.
Question 3
What is the primary purpose of a transformer turns ratio (TTR) test?
A. Measure winding resistance
B. Evaluate insulation resistance
C. Verify the transformer's turns ratio and detect winding defects
D. Determine transformer oil moisture
Rationale: A transformer turns ratio test confirms that the voltage ratio
matches the design specifications. Deviations may indicate shorted
turns, winding damage, incorrect tap settings, or manufacturing
defects. This test is commonly performed during commissioning and
maintenance.
,Question 4
When measuring contact resistance of a circuit breaker, the preferred
instrument is a:
A. Standard ohmmeter
B. Clamp meter
C. Micro-ohmmeter (DLRO)
D. Phase rotation meter
Rationale: Contact resistance measurements require high-current
injection and very accurate low-resistance measurements. A digital low-
resistance ohmmeter (DLRO) or micro-ohmmeter provides precise
readings in micro-ohms, helping identify worn or contaminated breaker
contacts.
Question 5
A current transformer (CT) secondary should never be left open while
the primary is energized because:
A. The CT will stop producing current.
B. The CT fuse will always blow.
C. Dangerously high voltages may develop across the secondary
terminals.
D. The primary winding will short circuit.
Rationale: An energized CT with an open secondary can generate
hazardous voltages capable of damaging equipment and causing severe
injury. CT secondary circuits should always remain connected to a
burden or be shorted before disconnecting instrumentation.
, Question 6
Which document provides acceptance testing specifications commonly
used for electrical power equipment?
A. NEC Article 250
B. IEEE 1584
C. NETA Acceptance Testing Specifications (ATS)
D. ANSI Z535
Rationale: NETA ATS provides detailed acceptance testing procedures,
recommended test values, and inspection criteria for newly installed
electrical equipment. It is widely used during commissioning and quality
assurance.
Question 7
A polarization index (PI) test compares insulation resistance measured
after:
A. 30 seconds and 1 minute
B. 1 minute and 10 minutes
C. 2 minutes and 20 minutes
D. 10 minutes and 20 minutes
Rationale: The polarization index is calculated by dividing the 10-minute
insulation resistance value by the 1-minute value. A higher PI generally
indicates cleaner and drier insulation with good dielectric properties.
Certification Exam Questions and
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf.
Question 1
A technician is performing insulation resistance testing on a de-
energized medium-voltage cable. Which instrument is most appropriate
for this task?
A. Digital multimeter
B. Clamp-on ammeter
C. Megohmmeter (Insulation Resistance Tester)
D. Oscilloscope
Rationale: A megohmmeter applies a high DC voltage (commonly 500 V,
1 kV, 2.5 kV, or 5 kV depending on the equipment) to measure insulation
resistance. It is specifically designed to detect insulation deterioration,
moisture contamination, and leakage paths. A standard multimeter
cannot adequately test insulation integrity because it applies only a low
test voltage.
,Question 2
Before conducting any electrical power testing on energized equipment,
the technician's highest priority is to:
A. Verify equipment age
B. Review previous maintenance records
C. Follow lockout/tagout procedures and applicable electrical safety
requirements
D. Clean all testing instruments
Rationale: Personnel safety is always the first priority. Lockout/tagout
(LOTO), verification of absence of voltage, proper PPE selection, and
compliance with NFPA 70E and OSHA requirements help prevent
electrical shock, arc flash, and equipment damage during testing.
Question 3
What is the primary purpose of a transformer turns ratio (TTR) test?
A. Measure winding resistance
B. Evaluate insulation resistance
C. Verify the transformer's turns ratio and detect winding defects
D. Determine transformer oil moisture
Rationale: A transformer turns ratio test confirms that the voltage ratio
matches the design specifications. Deviations may indicate shorted
turns, winding damage, incorrect tap settings, or manufacturing
defects. This test is commonly performed during commissioning and
maintenance.
,Question 4
When measuring contact resistance of a circuit breaker, the preferred
instrument is a:
A. Standard ohmmeter
B. Clamp meter
C. Micro-ohmmeter (DLRO)
D. Phase rotation meter
Rationale: Contact resistance measurements require high-current
injection and very accurate low-resistance measurements. A digital low-
resistance ohmmeter (DLRO) or micro-ohmmeter provides precise
readings in micro-ohms, helping identify worn or contaminated breaker
contacts.
Question 5
A current transformer (CT) secondary should never be left open while
the primary is energized because:
A. The CT will stop producing current.
B. The CT fuse will always blow.
C. Dangerously high voltages may develop across the secondary
terminals.
D. The primary winding will short circuit.
Rationale: An energized CT with an open secondary can generate
hazardous voltages capable of damaging equipment and causing severe
injury. CT secondary circuits should always remain connected to a
burden or be shorted before disconnecting instrumentation.
, Question 6
Which document provides acceptance testing specifications commonly
used for electrical power equipment?
A. NEC Article 250
B. IEEE 1584
C. NETA Acceptance Testing Specifications (ATS)
D. ANSI Z535
Rationale: NETA ATS provides detailed acceptance testing procedures,
recommended test values, and inspection criteria for newly installed
electrical equipment. It is widely used during commissioning and quality
assurance.
Question 7
A polarization index (PI) test compares insulation resistance measured
after:
A. 30 seconds and 1 minute
B. 1 minute and 10 minutes
C. 2 minutes and 20 minutes
D. 10 minutes and 20 minutes
Rationale: The polarization index is calculated by dividing the 10-minute
insulation resistance value by the 1-minute value. A higher PI generally
indicates cleaner and drier insulation with good dielectric properties.
