In order to protect the electrical equipment and workers’ safety, the electrical control system of crane should have the following protection measures.
1. Main disconnector.  You check and maintain the electrical equipment after cutting off the power .Therefore; it has a disconnector or other precautions between the electrical equipment and grid. When the disconnector turns down, there must be a clear breakpoint to make sure the serviceman can see intuitively.
2. Short-circuit protection of total power circuit.  When the electrical equipment have broken insulation and phase fault ect, the short-circuit protection should cut off the power quickly. The short-circuit protection consists of fuse box and circuit breaker.
3. No-voltage protection of total power circuit. It means when the power is cut off, the total power circuit can break automatically. And when power restoration, the circuit can’t connect automatically.
4. Zero protection. The motor adopt the controller which can’t reset automatically.
5. Surge protection of motor. When the rated power > 1KW, the surge protection can be set up alone.
6. Emergency power switch. It can’t reset automatically.
7. Safety interlocks protection. The crane should equip with the safety interlock. When opening the port, it can cut off the power.
8. Limiting position protection. In order to avoid the mistakes and negligence of work, the crane should have the limiting protection.