EV High Voltage Safety Technician
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A Instant Download Pdf
1. What is the primary purpose of a high-voltage safety system in an electric
vehicle?
A. To increase charging speed
B. To protect occupants and technicians from hazardous electrical energy
C. To improve battery capacity
D. To reduce vehicle weight
Answer: To protect occupants and technicians from hazardous electrical energy
Rationale: The high-voltage safety system is designed to prevent unintended
contact with dangerous electrical energy and to isolate the high-voltage system
when necessary.
2. Which component commonly stores the highest amount of electrical
energy in an EV?
A. 12-volt battery
B. High-voltage traction battery
C. Auxiliary fuse
D. Infotainment capacitor
Answer: High-voltage traction battery
,Rationale: The traction battery contains substantial stored electrical energy and
can present severe shock, arc-flash, and fire hazards.
3. What should a technician do before beginning high-voltage service?
A. Remove the vehicle's tires
B. Disable the high-voltage system according to the manufacturer's procedure
C. Disconnect the radio
D. Start the engine
Answer: Disable the high-voltage system according to the manufacturer's
procedure
Rationale: Manufacturer procedures identify the required shutdown, isolation,
lockout, and verification steps for safely servicing the vehicle.
4. What does PPE stand for?
A. Power Protection Equipment
B. Personal Protective Equipment
C. Primary Power Enclosure
D. Protective Power Electronics
Answer: Personal Protective Equipment
Rationale: PPE includes equipment such as voltage-rated gloves, eye protection,
and other protective items used to reduce exposure to workplace hazards.
5. Why are voltage-rated insulating gloves used when servicing high-voltage
EV systems?
A. To improve grip only
B. To provide electrical insulation against hazardous voltage
C. To prevent hand fatigue
D. To increase tool accuracy
Answer: To provide electrical insulation against hazardous voltage
,Rationale: Properly rated and maintained insulating gloves provide a barrier
between the technician and potentially energized conductors.
6. What is an important inspection requirement for insulating gloves?
A. They should only be inspected annually
B. They should be inspected before use for damage and contamination
C. They should be painted before use
D. They should always be stored wet
Answer: They should be inspected before use for damage and contamination
Rationale: Cuts, punctures, chemical contamination, aging, or other damage can
compromise glove insulation and increase shock risk.
7. What is the purpose of a high-voltage interlock circuit?
A. To control windshield wipers
B. To detect an open or improperly secured high-voltage connection
C. To adjust tire pressure
D. To regulate cabin temperature only
Answer: To detect an open or improperly secured high-voltage connection
Rationale: The interlock circuit helps prevent high-voltage operation when
connectors, covers, or other protected components are not properly secured.
8. Which color is commonly associated with high-voltage wiring in EVs?
A. Green
B. Orange
C. White
D. Blue
Answer: Orange
, Rationale: Orange is widely used by EV manufacturers to identify high-voltage
cables and components, although technicians should always verify the
manufacturer's identification system.
9. What is the safest assumption about an unidentified orange cable?
A. It is always low voltage
B. It may contain hazardous high voltage
C. It is a communication cable
D. It is a ground wire
Answer: It may contain hazardous high voltage
Rationale: Orange EV wiring should be treated as potentially hazardous until the
system has been properly isolated and verified according to service procedures.
10.What is the main danger of an electric arc?
A. Reduced tire pressure
B. Electrical burns, eye injury, fire, and blast effects
C. Battery discharge only
D. Reduced vehicle performance
Answer: Electrical burns, eye injury, fire, and blast effects
Rationale: An electrical arc can produce extreme heat, intense light, molten
metal, pressure, and hazardous fumes.
11.What should a technician use to verify the absence of voltage?
A. A flashlight
B. An appropriately rated voltage tester or multimeter
C. A tire gauge
D. A scan tool alone
Answer: An appropriately rated voltage tester or multimeter
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A Instant Download Pdf
1. What is the primary purpose of a high-voltage safety system in an electric
vehicle?
A. To increase charging speed
B. To protect occupants and technicians from hazardous electrical energy
C. To improve battery capacity
D. To reduce vehicle weight
Answer: To protect occupants and technicians from hazardous electrical energy
Rationale: The high-voltage safety system is designed to prevent unintended
contact with dangerous electrical energy and to isolate the high-voltage system
when necessary.
2. Which component commonly stores the highest amount of electrical
energy in an EV?
A. 12-volt battery
B. High-voltage traction battery
C. Auxiliary fuse
D. Infotainment capacitor
Answer: High-voltage traction battery
,Rationale: The traction battery contains substantial stored electrical energy and
can present severe shock, arc-flash, and fire hazards.
3. What should a technician do before beginning high-voltage service?
A. Remove the vehicle's tires
B. Disable the high-voltage system according to the manufacturer's procedure
C. Disconnect the radio
D. Start the engine
Answer: Disable the high-voltage system according to the manufacturer's
procedure
Rationale: Manufacturer procedures identify the required shutdown, isolation,
lockout, and verification steps for safely servicing the vehicle.
4. What does PPE stand for?
A. Power Protection Equipment
B. Personal Protective Equipment
C. Primary Power Enclosure
D. Protective Power Electronics
Answer: Personal Protective Equipment
Rationale: PPE includes equipment such as voltage-rated gloves, eye protection,
and other protective items used to reduce exposure to workplace hazards.
5. Why are voltage-rated insulating gloves used when servicing high-voltage
EV systems?
A. To improve grip only
B. To provide electrical insulation against hazardous voltage
C. To prevent hand fatigue
D. To increase tool accuracy
Answer: To provide electrical insulation against hazardous voltage
,Rationale: Properly rated and maintained insulating gloves provide a barrier
between the technician and potentially energized conductors.
6. What is an important inspection requirement for insulating gloves?
A. They should only be inspected annually
B. They should be inspected before use for damage and contamination
C. They should be painted before use
D. They should always be stored wet
Answer: They should be inspected before use for damage and contamination
Rationale: Cuts, punctures, chemical contamination, aging, or other damage can
compromise glove insulation and increase shock risk.
7. What is the purpose of a high-voltage interlock circuit?
A. To control windshield wipers
B. To detect an open or improperly secured high-voltage connection
C. To adjust tire pressure
D. To regulate cabin temperature only
Answer: To detect an open or improperly secured high-voltage connection
Rationale: The interlock circuit helps prevent high-voltage operation when
connectors, covers, or other protected components are not properly secured.
8. Which color is commonly associated with high-voltage wiring in EVs?
A. Green
B. Orange
C. White
D. Blue
Answer: Orange
, Rationale: Orange is widely used by EV manufacturers to identify high-voltage
cables and components, although technicians should always verify the
manufacturer's identification system.
9. What is the safest assumption about an unidentified orange cable?
A. It is always low voltage
B. It may contain hazardous high voltage
C. It is a communication cable
D. It is a ground wire
Answer: It may contain hazardous high voltage
Rationale: Orange EV wiring should be treated as potentially hazardous until the
system has been properly isolated and verified according to service procedures.
10.What is the main danger of an electric arc?
A. Reduced tire pressure
B. Electrical burns, eye injury, fire, and blast effects
C. Battery discharge only
D. Reduced vehicle performance
Answer: Electrical burns, eye injury, fire, and blast effects
Rationale: An electrical arc can produce extreme heat, intense light, molten
metal, pressure, and hazardous fumes.
11.What should a technician use to verify the absence of voltage?
A. A flashlight
B. An appropriately rated voltage tester or multimeter
C. A tire gauge
D. A scan tool alone
Answer: An appropriately rated voltage tester or multimeter
