Control Circuit Undervoltage

What does UV2 mean?

This fault indicates that the internal control power supply voltage within the inverter has dropped below its acceptable level. This often points to an issue with the inverter's internal power supply board or auxiliary power components. When the control circuit loses stable power, the inverter cannot operate reliably or safely, leading to a complete shutdown.

• Internal power supply component failure within the inverter's control section (e.g., DC-DC converter).
• Excessive load placed on the inverter's auxiliary power outputs (e.g., 24VDC output supplying too many external devices).
• Short circuit detected on an auxiliary power output (e.g., 24VDC, 10V analog supply) or connected control wiring.
• Damaged or faulty control board within the inverter, preventing stable internal power regulation.
• High ambient temperature stressing internal power supply components.

Click steps to track your progress.

1. 1

   1. Measure the internal 24VDC control supply output (if accessible) using a multimeter to verify stable voltage.

2. 2

   2. Disconnect all external devices connected to the inverter's auxiliary power outputs (e.g., 24VDC terminals, 10V analog supply).

3. 3

   3. Check for short circuits on the control wiring connected to inverter I/O terminals (e.g., digital inputs, analog outputs).

4. 4

   4. Visually inspect the inverter's control board for any signs of physical damage, burnt components, or loose ribbon cable connections.

5. 5

   5. Verify the ambient operating temperature is within the inverter's specified range, as excessive heat can degrade internal components.