Zaptec charger displays E04; app message: ‘Overcurrent / load exceeded’ and charging stops shortly after start

Safety first: Overcurrent can overheat wiring. If you smell burning or see discoloration near the charger, switch off power and call a professional.

Steps:

• Check configured current limit: In the Zaptec app or backend, verify that the maximum current is set to match the circuit breaker rating (e.g., 16 A or 32 A). Reduce the limit if necessary.
• Check for simultaneous loads: If the charger is part of a load-balancing group, ensure the building’s main fuse is not overloaded by other appliances. Reduce other loads and retry.
• Inspect supply breaker: Confirm the breaker feeding the charger is correctly rated and not undersized.
• Power-cycle and test: Turn the breaker OFF for 2 minutes, then ON. Start a new session and monitor if E04 reappears immediately or only at high current.
• If E04 persists at low current: The internal current sensor (CT) or measurement circuit may be faulty. A technician should open the unit, inspect terminals for heat damage, and replace the main control board if needed.