中文
含义
低压保护。制冷系统低压侧压力低于安全下限，低压开关断开或压力传感器检测到超低值，系统停机以防止压缩机回液或干运行。
常见原因
- 系统制冷剂严重泄漏，缺少制冷剂
- 室内机蒸发器结霜严重，气流通道堵塞
- 室内机滤网或蒸发器严重脏堵
- 制冷剂管路过滤器（干燥过滤器）堵塞
- 膨胀阀或毛细管冰堵（系统中水分含量过高）
自助排查
- 检查低压表读数——停机后平衡压力若低于0.3MPa（R32）则制冷剂严重不足
- 清洗室内机滤网和蒸发器翅片
- 观察室内机蒸发器是否有结霜现象，若有则可能是滤网脏堵或风量不足
- 若确认制冷剂不足，需检漏补氟；若过滤器堵塞则需更换并彻底抽真空
English
Meaning
Low pressure protection. The low-side refrigerant pressure has dropped below the safety limit — the low-pressure switch has opened or the pressure sensor detects an under-limit value. The system stops to prevent liquid slugging or dry compressor operation.
Common Causes
- Severe refrigerant leak — the system is low on refrigerant
- Heavy frost buildup on the indoor evaporator blocking the airflow path
- Clogged indoor air filter or heavily fouled evaporator coils
- Blocked filter drier in the refrigerant line
- Iced-up expansion valve or capillary tube (excessive moisture in the system)
Self-Check Steps
- Check the low-pressure gauge reading — if the static pressure after shutdown is below 0.3MPa (R32), refrigerant is critically low
- Clean the indoor air filter and evaporator fins
- Check for frost on the evaporator — frost indicates a dirty filter or insufficient airflow
- If refrigerant is confirmed low, locate the leak and recharge; if the filter drier is blocked, replace it and evacuate the system thoroughly