Applicable Systems
Sunny Boy
Symptoms
Frequency shift out of range. The rate of change of grid frequency (df/dt) exceeds the allowed limit.
Possible Causes
- Grid with high renewable penetration causing rapid frequency changes
- Grid generator governor response too slow
- Large load connection or disconnection causing frequency step
- Inverter frequency measurement noise or interference
Troubleshooting Steps
- Step 1: Check the equipment status and fault indicators to confirm the active fault code
Fault indicator or HMI displays code 701 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 701 mean on the SMA Sunny Boy?
Fault 701 on the SMA Sunny Boy indicates: Frequency shift out of range. The rate of change of grid frequency (df/dt) exceeds the allowed limit. Refer to the equipment manual and manufacturer support for specific troubleshooting steps.
- Q: Can I continue operating the equipment with fault 701 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.
Comments (0)
Share your experience to help others facing the same problem.
Leave a Comment
Source: SMA Sunny Boy Inverter Installation and Operation Manual, SMA Official Documentation
Category: PLC & VFD
Published: 2026-10-02
No comments yet. Be the first to share your experience!