Undervoltage
Mitsubishi Electric · FR-D700 Inverter
Was bedeutet Undervoltage ?
The voltage at the main circuit power supply has dropped below an acceptable operating level. This can be caused by issues in the incoming power supply line, insufficient capacity, or a fault within the power supply itself, leading to insufficient power for the inverter and potential damage if the voltage fluctuates excessively. The inverter output is shut off.
Häufige Ursachen
- Sag or complete loss of one or more phases in the incoming AC main power supply (e.g., R/L1, S/L2, T/L3 terminals).
- Insufficient power supply capacity for the driven load, causing voltage drops during peak current demand.
- Loose or corroded connections in the main power circuit, leading to voltage drop under load.
- Faulty main circuit capacitors within the inverter, affecting DC bus voltage regulation.
Reparaturschritte & Checkliste
Klicken Sie auf Schritte, um Ihren Fortschritt zu verfolgen.
- 1
Measure the incoming AC line voltage at the inverter's main input terminals (R/L1, S/L2, T/L3) using a multimeter or power quality analyzer.
- 2
Check for loose connections or corrosion on the main power wiring terminals, both at the inverter and upstream circuit breakers/contactors.
- 3
Verify the capacity of the upstream transformer and circuit breaker to ensure they can adequately supply the inverter and motor.
- 4
Monitor the DC bus voltage (e.g., using Pr. 08 "DC Bus Voltage" monitor function) during operation to observe sag trends.
- 5
Consult an electrician to inspect the facility's power distribution system for sags or imbalances affecting the inverter's supply.