EVT Safety Standards & Regulatory 3 — Questions and Answers
Question 1: What is the primary purpose of the interlock system required by SAE J1772 on EV charging connectors?
- To measure charging current accuracy
- To prevent the vehicle from moving while plugged in (Correct answer)
- To regulate battery cell balancing during charging
- To communicate state of charge to the EVSE
Correct answer: To prevent the vehicle from moving while plugged in
The proximity pilot and control pilot interlock in SAE J1772 prevents the vehicle from driving away while the charging connector is still engaged.
Question 2: Under NFPA 70 (NEC), Article 625 governs EV charging equipment. What minimum clearance is typically required between an outdoor EVSE and a building's gas meter?
- 2 feet
- 3 feet (Correct answer)
- 5 feet
- 10 feet
Correct answer: 3 feet
NEC Article 625 and local codes generally require a minimum 3-foot clearance between EVSE installations and gas service meters to reduce ignition risk.
Question 3: Which standard defines the Combined Charging System (CCS) connector and its communication protocol used in North American DC fast charging?
- SAE J1772
- SAE J2847 (Correct answer)
- SAE J1850
- SAE J3068
Correct answer: SAE J2847
SAE J2847 (along with J1772 for the physical connector) defines the communication requirements for the CCS DC fast charging system used in North America.
Question 4: An EV technician discovers a damaged high-voltage orange cable during inspection. Per safety regulations, what is the correct immediate action?
- Wrap the damaged area with electrical tape and document for next service
- Disable the vehicle and do not operate until the cable is replaced (Correct answer)
- Reroute the cable away from heat sources and continue service
- Apply dielectric grease to the damaged area as a temporary fix
Correct answer: Disable the vehicle and do not operate until the cable is replaced
A damaged HV orange cable poses immediate electrocution and fire risk; the vehicle must be taken out of service and the cable replaced before any operation.
Question 5: What does the term 'de-energization' mean in the context of OSHA Lockout/Tagout procedures for EV service?
- Draining the 12V auxiliary battery
- Removing all electrical energy sources and verifying zero energy state (Correct answer)
- Disconnecting the vehicle from shore power only
- Placing the vehicle in park and turning off the ignition
Correct answer: Removing all electrical energy sources and verifying zero energy state
De-energization under LOTO means isolating all energy sources—including HV battery—and verifying through measurement that the system is at zero energy state before work begins.
Question 6: California's Zero Emission Vehicle (ZEV) mandate is enforced by which state agency?
- California Department of Motor Vehicles (DMV)
- California Air Resources Board (CARB) (Correct answer)
- California Energy Commission (CEC)
- California Public Utilities Commission (CPUC)
Correct answer: California Air Resources Board (CARB)
The California Air Resources Board (CARB) enforces the ZEV mandate, requiring automakers to sell a percentage of zero-emission vehicles in California.
Question 7: What is the purpose of the 'ground fault' protection circuit required in EVSE installations per NEC Article 625?
- To protect the vehicle battery from overcharging
- To detect unintended current paths to ground and interrupt the circuit (Correct answer)
- To regulate voltage fluctuations from the utility grid
- To monitor the charging cable temperature
Correct answer: To detect unintended current paths to ground and interrupt the circuit
Ground fault protection detects current leakage through unintended paths (like a person's body) and interrupts the circuit to prevent electrocution.
EVT Safety Standards & Regulatory 3
What is the primary purpose of the interlock system required by SAE J1772 on EV charging connectors?