Master Electrician Exam (NEC)Special Occupancies, Equipment, and ConditionsEasy
A master electrician is installing a new electric vehicle (EV) charging station at a commercial parking garage. The charging station is rated for 48A continuous operation. Which of the following overcurrent protective device (OCPD) ratings is compliant with NEC requirements for this installation?
- A80A
- B50A
- C60A
- D70A
Show answer & explanationAnswer & explanation
Correct answer: C. 60A
According to NEC 625.41, the overcurrent device for EV charging equipment must be sized for not less than 125% of the maximum continuous load. For a 48A continuous load, the minimum OCPD size is 48A * 1.25 = 60A.
Why the other options are wrong
- A. 80A is larger than required but acceptable if the next standard size is used and conductor protection is maintained.
- B. 50A is too small (48A * 1.25 = 60A).
- D. 70A is larger than required but acceptable if the next standard size is used and conductor protection is maintained.
EV Charger OCPD Sizing
Overcurrent protective devices for electric vehicle charging equipment must be sized for not less than 125% of the maximum continuous load.
- Continuous load factor: 125%.
- Applies to EV charging equipment.
- Ensures OCPD can handle prolonged operation without nuisance tripping.
Memory trick: EV Chargers: Just like ovens, they're continuous, so add 25% for safety.