Controller shows E015 Earth Fault / Ground Fault, generator trips off load

Safety first: Earth faults can be hazardous. Do not repeatedly reset and re‑energize without finding the cause. Only qualified electricians should work on live circuits.

• Inspect cables and junction boxes: Look for damaged insulation, water ingress, or burnt marks on generator output cables and terminations.
• Check insulation resistance: With the generator isolated and de‑energized, perform an insulation resistance test (megger) between phases and earth. Low readings indicate a fault.
• Verify bonding: Confirm that neutral‑earth bonding is configured as per Atlas Copco and site design (TN, TT, etc.). Incorrect bonding can cause nuisance trips.
• Examine earth fault CT and relay: Ensure the CT is correctly installed around all phase conductors and wired properly to the relay or controller input.

Persistent earth fault alarms require detailed electrical testing and should be handled by a specialist.