UU fault in an INVT GD10 inverter indicates an Under Voltage condition. This means the input voltage to the drive has fallen below a specified threshold.

Common Causes of UU Faults:

1. Insufficient Input Voltage:

   • Low Supply Voltage: Ensure the input voltage is within the specified range for the inverter.
   • Voltage Drops: Check for voltage drops in the power supply cables, especially during high load conditions.
   • Weak Power Supply: A weak or overloaded power supply can also cause undervoltage.

2. Internal Inverter Issues:

   • Faulty Rectifier: A damaged rectifier can prevent proper voltage conversion.
   • Capacitor Problems: Aging or damaged capacitors can reduce the DC bus voltage.

3. External Factors:

   • Power Supply Fluctuations: Fluctuations in the power supply, such as brownouts or sags, can trigger the UU fault.
   • Environmental Conditions: Extreme temperature or humidity can affect the performance of the inverter.

Troubleshooting Steps:

1. Verify Input Voltage:

   • Use a voltmeter to measure the input voltage at the inverter terminals.
   • Check for voltage drops in the power cables.
   • Ensure the power supply is rated for the inverter's load.

2. Inspect Internal Components:

   • Visually inspect the rectifier diodes and capacitors for any signs of damage or overheating.
   • Consult the inverter's manual for specific troubleshooting guidelines and component replacement procedures.

3. Check Inverter Settings:

   • Review the inverter's parameter settings to ensure they are appropriate for the application.
   • Some settings, such as the undervoltage trip level, can be adjusted to accommodate specific power supply conditions.