Applicable Systems
SUN2000
Symptoms
Grid undervoltage detected. The inverter measures a grid voltage below the minimum allowed input voltage. Theinverter disconnects to protect against unstable grid conditions and ensure compliance with grid standards.
Possible Causes
- Grid voltage from utility drops below inverter minimum AC voltage rating
- Voltage drop in AC wiring due to undersized cable or long run
- Grid transformer tap setting too low for local conditions
- Inverter AC voltage measurement circuit fault
Troubleshooting Steps
- Step 1: Check the equipment status and fault indicators to confirm the active fault code
Fault indicator or HMI displays code 106 as active - Step 2: Verify all electrical connections, wiring harnesses, and connector seating
All connections secure, no corrosion, loose pins, or damaged wires - Step 3: Measure the input power supply voltage at the equipment terminals with a multimeter
Voltage reading is within the equipment's specified operating range - Step 4: Inspect the power input wiring, breakers, and fuses for damage or degradation
Wiring intact, breakers closed, fuses continuous - Step 5: Check for transient voltage events or power quality issues using a power analyzer
No sustained overvoltage, undervoltage, or phase imbalance detected - Step 6: Reset the fault after correcting the power issue: fix root cause, then press RESET or power-cycle
Fault clears and equipment resumes normal operation
How to Reset
To reset: 1) Identify and fix the root cause described in the fault symptoms. 2) Press RESET on the HMI or controller, or power-cycle the equipment. 3) If the fault recurs, contact manufacturer service. Caution: Document the fault code and context before resetting.
Frequently Asked Questions
- Q: What does fault code 106 mean on the Huawei SUN2000?
Fault 106 on the Huawei SUN2000 indicates: Grid undervoltage detected. The inverter measures a grid voltage below the minimum allowed input voltage. The inverter disconnects to protect against unstable grid conditions and ensure compliance with grid standards. Refer to the equipment manual and manufacturer support for specific troubleshooting steps.
- Q: Can I continue operating the equipment with fault 106 active?
No. The equipment has detected a fault condition and has taken protective action (typically stopping or derating). Continuing to operate without fixing the root cause may cause further damage. Always investigate and fix the fault before resuming operation.
Source: Huawei SUN2000 Series Inverter User Manual, Huawei Official Support (support.huawei.com)
Category: PLC & VFD