Overcurrent protection for feeders and branch circuits supplying EVSE shall be sized for ____.

Overcurrent protection for feeders and branch circuits supplying EVSE shall be sized for ____.

• A. In-Rush Current
• B. Nominal Voltage
• C. Intermittent Duty
• D. Continuous Duty

Answer: (D)

EV charging sessions can run for hours, so the circuits feeding EVSE are treated as continuous loads. Because of that, overcurrent protection must be sized to handle the ongoing current, typically at 125% of the continuous operating current, to prevent nuisance tripping while still protecting conductors. The inrush surge at connection is a transient and not the basis for continuous-duty sizing. Nominal voltage and intermittent duty describe different aspects that don’t drive the sizing rule for EVSE. So the correct concept is continuous duty.

EV charging sessions can run for hours, so the circuits feeding EVSE are treated as continuous loads. Because of that, overcurrent protection must be sized to handle the ongoing current, typically at 125% of the continuous operating current, to prevent nuisance tripping while still protecting conductors. The inrush surge at connection is a transient and not the basis for continuous-duty sizing. Nominal voltage and intermittent duty describe different aspects that don’t drive the sizing rule for EVSE. So the correct concept is continuous duty.