EVT EVT Charging Systems & Infrastructure 1 — Questions and Answers
Question 1: What SAE standard defines the Combined Charging System (CCS) connector used for DC fast charging in North America?
- SAE J1772 (Correct answer)
- SAE J2954
- SAE J1171
- SAE J1113
Correct answer: SAE J1772
SAE J1772 defines both the AC Level 1/Level 2 and the CCS DC fast-charge connector standard widely used in North America.
Question 2: A Level 2 EVSE operates at 240V AC and delivers up to 80A continuous. What is the maximum continuous output power in kilowatts?
- 12.8 kW
- 19.2 kW (Correct answer)
- 7.2 kW
- 11.5 kW
Correct answer: 19.2 kW
Power equals voltage × current, so 240V × 80A = 19,200 W = 19.2 kW.
Question 3: Which communication protocol does the CCS DC fast charger use to negotiate charging parameters with the vehicle?
- CAN bus
- ISO 15118 / DIN 70121 (Correct answer)
- MODBUS RTU
- J1850 VPW
Correct answer: ISO 15118 / DIN 70121
ISO 15118 (and its predecessor DIN 70121) defines the power line communication protocol used between CCS chargers and EVs to negotiate voltage, current, and authentication.
Question 4: What is the purpose of the Control Pilot (CP) signal in an SAE J1772 charging circuit?
- It measures the state of charge of the battery
- It carries the AC power to the vehicle inlet
- It communicates vehicle connection state and maximum available current to the EVSE (Correct answer)
- It monitors ground fault current
Correct answer: It communicates vehicle connection state and maximum available current to the EVSE
The Control Pilot is a PWM signal whose duty cycle tells the vehicle the EVSE's maximum available current, and whose voltage level indicates the connection state.
Question 5: A technician measures 0V on the Control Pilot line while the EV is plugged into a Level 2 EVSE. What does this most likely indicate?
- Normal state – vehicle is fully charged
- EVSE is in a fault or not energized state (Correct answer)
- Vehicle is actively drawing maximum charge current
- Ground fault detected in the cable
Correct answer: EVSE is in a fault or not energized state
A 0V CP signal indicates the EVSE is de-energized or in a fault condition; normal standby is +12V DC.
Question 6: Which NEC article primarily governs the installation of electric vehicle supply equipment (EVSE) in the United States?
- NEC Article 480
- NEC Article 625 (Correct answer)
- NEC Article 702
- NEC Article 445
Correct answer: NEC Article 625
NEC Article 625 covers Electric Vehicle Power Transfer Systems, including EVSE installation requirements for wiring, grounding, and protection.
EVT EVT Charging Systems & Infrastructure 1
What SAE standard defines the Combined Charging System (CCS) connector used for DC fast charging in North America?