and disconnected, so contact welding failures are prone to occur. When the crane needs to be accurately positioned or emergency stopped during operation, a collision accident may occur if the crane refuses to stop due to contact welding. In order to solve this problem, a crane lift mechanism rejection design was proposed.РFrom three aspects to solve this problem, one is that contactor contact welding leads to its illogical action, which can be increased by an intermediate relay to determine; Second, in order to avoid contactor, relay petition leading to protection from false start, This refusal protection set a short time delay, ie, a time relay is needed. The third is that once the contactor refuses to jump, the shunt trip action of the main circuit breaker is used to perform protection.
全文预览
