求翻译：确认起重机上无人时，才可以闭合主电源。如电源断路装置上加锁或有标牌时，应由有关人员除掉后，才可以闭合主电源。闭合主电源前，应使所有控制器手柄置于零位。是什么意思？

Sure no one on the crane when it can close the main power supply. If power disconnect device lock or signs, the officers concerned should be removed before it can close the main power supply. Before closing the main power should be placed on controller handle all zero.

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Confirmed when on hoist crane nobody, only then may close the main power source.When the power source shutting-off device locks or has the product label, should after the concerned personnel remove, only then may close the main power source.In front of the closed main power source, should cause all

Confirm when no one on the crane can only closing main power. Power lock on a trip or when there are signs, should be made by the officer after you get rid of before we can close main power. Before closing main power, should make all controller handles at the zero position.

Confirm when no one on the crane can only closing main power. Power lock on a trip or when there are signs, should be made by the officer after you get rid of before we can close main power. Before closing main power, should make all controller handles at the zero position.