Undervoltage

What does E.UVT mean?

This fault indicates that the DC bus voltage within the FR-A800 inverter has dropped below a specified minimum threshold. This typically occurs due to low incoming AC supply voltage or during an instantaneous power failure event. The inverter trips to prevent damage from insufficient operating voltage.

• The incoming AC power supply voltage is consistently below the FR-A800 inverter's rated input voltage.
• Significant voltage sag or transient dip in the power supply.
• Loose or high-resistance connections in the main power circuit to the inverter.
• Internal FR-A800 inverter power supply issue (less common if other faults are not present).

Click steps to track your progress.

1. 1

   Measure the incoming AC line voltage (R1/L11, S1/L21, T1/L31) at the FR-A800 inverter's input terminals and compare it to the inverter's rated input voltage.

2. 2

   Inspect all main circuit power wiring and connections for looseness, corrosion, or signs of overheating.

3. 3

   Verify that the power supply capacity is sufficient and not subject to excessive voltage drop under load.

4. 4

   Check for any external devices or loads connected to the same power circuit that might be causing voltage dips.

5. 5

   If the undervoltage persists and the external power supply is confirmed stable and correct, the inverter's rectifier or DC bus capacitor bank may be degraded, requiring professional service.