Cause : External fault comes when a fault that occurs outside of the drive itself, but can still have a significant impact on its operation. The external fault is designed to protect the drive and the connected motor from damage due to issues outside the drive’s control.

"External fault" in "delta drive" indicate a fault condition that is triggered by an external signal or input. This fault typically does not originate from within the drive itself but is caused by external devices or systems connected to it.

Common Causes of External Fault in Delta Drives:

1. External Emergency Stop:

   • An emergency stop (E-stop) button or circuit is triggered externally, sending a signal to the drive to stop operation and trigger a fault.

2. External Protective Devices:

   • Protective devices such as overload relays, motor protection breakers, or external temperature sensors detect a fault condition and send a fault signal to the drive.

3. PLC or Control System Fault:

   • If the Delta drive is connected to a programmable logic controller (PLC) or external control system, an error or fault in the PLC can send an external fault signal to the drive.

4. Incorrect External Wiring:

   • Incorrect or loose wiring between the drive and external devices, such as sensors, relays, or other control systems, can cause intermittent or continuous external fault signals.

5. Faulty External Devices:

   • Malfunctioning external devices (e.g., relays, limit switches, temperature sensors) can falsely trigger an external fault if they send an erroneous signal to the drive.

6. External Command Signal Failure:

   • A command or control signal from an external source, such as a start/stop signal, may fail, leading to an external fault. This could be due to issues like signal loss or incorrect signal voltage.

7. Power Supply Issues to External Devices:

   • External devices connected to the drive, such as control panels or sensors, may lose power or operate outside their voltage limits, causing them to trigger a fault in the drive.

8. External Feedback Devices:

   • Feedback devices like encoders, thermistors, or tachometers may send faulty or incorrect signals to the drive, causing an external fault.

Troubleshooting Steps for External Fault in Delta Drives:

1. Check External Fault Inputs:

   • Review the wiring diagrams and documentation to identify which external inputs are being used for fault detection. The external fault signal usually enters through a specific terminal on the drive's control board (e.g., DI, Digital Input).

2. Inspect Emergency Stop Circuit:

   • If an emergency stop is connected to the drive, verify that it is not engaged. Check for any issues with the wiring or the E-stop button itself.
   • Reset the emergency stop button if it was engaged and check for proper functioning.

3. Examine External Protective Devices:

   • Check external protective devices such as overload relays, temperature sensors, or external motor protection devices to ensure they are not triggering a fault condition.
   • If any external device has tripped, investigate the root cause of why it was triggered (e.g., motor overload, overheating).

4. Inspect Wiring and Connections:

   • Inspect the wiring between the drive and any connected external devices for loose, disconnected, or damaged wires.
   • Ensure that all connections are properly secured and that there is no corrosion or damage at the terminals.

5. Check External Control System (PLC or HMI):

   • If the drive is connected to a PLC or an HMI (Human Machine Interface), check the logic or configuration to ensure that no fault signals are being sent due to a programming issue or control system malfunction.

6. Test External Command Signals:

   • If the external fault is linked to a start/stop or run command signal, verify that the external signal source is functioning properly and that the correct voltage or current is being supplied to the drive.
   • Use a multimeter to check that control signals from switches, relays, or PLC outputs are correct.