Unplugged condition: check whether the power supply equipment is sending electricity to the electric hoist switch power supply. Generally, test pen is used to detect it. If there is no electricity, it will work after sending electricity.

2. The condition of being phase deficient: Check the electric hoist main, route of control circuit of electrical damage, broken or poor contact phenomenon, hydraulic jack manufacturer also can make the hoist motor open phase can't normal work, in this situation, need to repair the main, control circuit, maintenance, in order to avoid the main and control circuits to three-phase motor phase and switch power supply damage, or hoist motor to run suddenly, Damage, must will be broken on the way to hoist motor from the power plug, only to master and control circuit of electric transmission, then start to start or stop the power switch and check the profiling control appliances and the work of the route, route of abnormal electrical appliances or carry out repair or moved around, no problem when determining the main and control circuits, trial run again. The working voltage is too low: if the dc voltage of the hydraulic jack is ten percent lower than the rated current, the motor running distance is too small, so that the hoist is not moved goods, and can not work, when checking, use digital multimeter or ammeter to accurately measure the dc voltage of the motor.