Display shows E04 and charging stops shortly after starting, or will not start at all.

Safety first: Overvoltage can permanently damage the charger and vehicle. Turn off power at the breaker before inspection.

• 1. Measure supply voltage: Have a qualified person measure line-to-line and line-to-neutral voltage at the charger input. Confirm it matches the Primecom charger's rating (typically 208–240V AC for Level 2 models).
• 2. Check for miswiring: Ensure the charger is not connected to a 277V or 3-phase circuit unless specifically rated. Correct any miswiring immediately.
• 3. Inspect input terminals: With power off, tighten all line and neutral screws in the input terminal block. Loose connections can cause transient overvoltage.
• 4. Remove surge-prone accessories: Avoid using long, undersized extension cords or questionable adapters that may cause voltage fluctuations.
• 5. If voltage is normal: If measured voltage is within spec and E04 persists, the internal voltage sensing or protection circuit on the main control board may be faulty and require replacement.