External Fault (LI/Bit)
Schneider Electric · Altivar Machine ATV320 Variable Speed Drive
¿Qué significa EPF1 ?
An external fault detected from a logic input (LI) or a local link. This indicates that an external safety device, sensor, or interlock has triggered a fault condition, causing the drive to stop. The specific cause depends on the connected device and its state.
Causas comunes
- Open circuit in the wiring connecting an external safety device (e.g., E-stop, limit switch) to the drive's logic input (e.g., LI3).
- Mechanical failure of an external sensor or interlock switch preventing its contacts from closing or opening correctly.
- Incorrect configuration of the drive's logic input (e.g., Parameter P5-01 set to N.O. instead of N.C. contact).
- Loss of 24VDC supply to the external control circuit, causing all connected inputs to appear open.
- Electrical noise or transient voltage on the logic input line causing a false fault trigger.
Pasos de reparación & Lista de verificación
Haga clic en los pasos para seguir su progreso.
- 1
1. Identify which logic input (e.g., LI3, LI4) is configured as the external fault trigger using the drive's parameter list (e.g., Parameter P5-01).
- 2
2. With input power OFF, verify continuity of the wiring from the external device's contacts to the drive's specified logic input terminal.
- 3
3. Monitor the status of the relevant logic input (e.g., LI3) on the drive's HMI or diagnostic display while actuating the external device.
- 4
4. Check the 24VDC power supply for the external control circuit to ensure it is within specified voltage range.
- 5
5. Temporarily bypass the external device (if safe to do so and following lockout/tagout) to confirm if the device itself is faulty.