CPCD30－S型叉车采用苏福马490型柴油机，用户反映启动困难。症状是，启动过程中，发动机尚未正常运转时，启动机就受到启动保护而自动停止工作。原因似乎是启动保护电路提前起作用。我们可根据启动保护电路图（见图1）来进行分析。假如蓄电池电容量不足，会出现启动无力，不会 CPCD30-S forklift with Sufu 490-type diesel engine, the user reflects the start-up difficulties. Symptoms are that, during start-up, the engine is not functioning properly and the starter is stopped and started automatically. The reason seems to be to start the protection circuit in advance to work. We can start the protection circuit diagram (see Figure 1) to analyze. If the battery capacity is insufficient, there will be weak start, no