The fault code "7807" on Siemens drives indeed indicates a "Short-circuit" fault. This fault occurs when there is an unintended connection between two conductors, resulting in a sudden increase in current flow, potentially damaging the drive or connected equipment. Here's how to address it:

1. Isolate Power: Immediately isolate power to the drive to prevent further damage or hazards. Follow proper lockout/tagout procedures to ensure the system remains de-energized during troubleshooting.

2. Inspect Motor and Drive Wiring: Carefully inspect all wiring connections, terminals, and cables associated with the drive and the motor. Look for any signs of damage, exposed wires, loose connections, or any visible indication of a short circuit. Pay close attention to areas where cables may have been pinched or crushed.

3. Check Motor Windings: Inspect the motor windings for any signs of damage, such as burnt insulation, melted wires, or visual indications of overheating. A short circuit within the motor windings can trigger this fault. If damage is evident, the motor may need to be repaired or replaced.

4. Verify Motor Parameters: Ensure that the motor parameters are correctly configured in the drive's settings. Incorrect motor parameters can lead to excessive current flow and trigger a short-circuit fault. Check parameters such as rated current, voltage, and frequency.

5. Inspect Drive Output Section: Check the drive's output section, including power transistors and IGBT modules, for any signs of damage or failure. A short-circuit fault in the drive's output section can trigger the fault code. Replace any faulty components as needed.

6. Review Drive Settings: Check the drive's control parameters and settings related to current limits and motor protection. Ensure that the settings are appropriate for the application and adjust them as necessary to prevent short-circuit faults.

7. Inspect Cooling System: Ensure that the cooling system for the drive and motor is functioning properly. Overheating can increase the risk of short circuits. Check for blocked ventilation openings, dirty cooling fins, or malfunctioning cooling fans.

8. Check for Ground Faults: Inspect the motor and drive system for ground faults. A ground fault can cause abnormal currents to flow through the motor, leading to short circuits. Use a multimeter or insulation tester to check for ground faults and address any issues found.

9. Consult Technical Documentation: Refer to the drive's user manual, technical documentation, or contact Siemens technical support for specific guidance on troubleshooting and resolving short-circuit faults.

By following these steps and addressing the potential causes, you can troubleshoot and resolve the short-circuit fault (7807) in your Siemens drive.