| Alarm ID | Alarm Name | Alarm Severity | Possible Cause | Suggestion |
| 301 | Abnormal Grid Voltage | Major | The power grid voltage is beyond the acceptable range. The possible causes are as follows:
| Cause ID = 4 1. If the alarm occurs accidentally, the power grid may be abnormal temporarily. The SUN2000 automatically recovers after detecting that the power grid becomes normal. 2. If the alarm occurs frequently, check whether the power grid voltage is within the acceptable range. If no, contact the local power operator. If yes, log in to the SUN2000 APP, SmartLogger, or NMS to modify the power grid overvoltage and undervoltage protection thresholds with the consent of the local power operator. 3. If the fault persists for a long time, check the AC switch and AC output power cable. Cause ID = 16/19/26 1. Check whether the grid-tied voltage exceeds the upper threshold. If yes, contact the local power operator. 2. If you have confirmed that the grid-tied voltage exceeds the upper threshold and obtained the consent of the local power operator, modify the overvoltage and undervoltage protection thresholds. 3. Check whether the peak power grid voltage exceeds the upper threshold. Cause ID = 28 1. If the exception is caused by an external fault, the SUN2000 automatically recovers after the fault is rectified. 2. If the alarm persists and affects the energy yield of the power station, contact the local power operator. Cause ID = 29 1. Check the AC voltage. 2. Check that the AC power cable is securely connected and that the AC switch is ON. Cause ID = 31/32/33 Check the impedance of output phase wire A (Cause ID = 31)/B (Cause ID = 32)/C (Cause ID = 33) to the PE and locate the position with lower impedance and resolve the issue. |