Crane overload limit device basic function

1. Early warning function
When the weight is ≥90%(manual change) of the rated load, the low frequency sound and light alarm is issued.

2. Alarm protection
When the weight is ≥100%(can be manually changed) rated load, emit a high-frequency audible and visual alarm, if a delay of a certain time (can be manually set), still not eliminate the alarm, then automatically disconnect the rising circuit, prohibit lifting action, and emit a continuous long alarm sound and alarm indicator high frequency flashing.

3. Immediate protection
When the weight is greater than 110%(can be manually changed) of the rated load, immediately disconnect the lifting circuit, prohibit lifting action, and emit a long alarm sound and alarm light flashing at high frequency.

4. Phase sequence protection
When the phase sequence of the connected three-phase power supply is wrong, the sound and light alarm is issued, the fault code is displayed, and the total power control contact and the rise circuit control contact are disconnected, and all operations are prohibited.

5. Lack of phase protection
A. When the device is connected to the power supply, if there is no phase a or phase B, the device does not work because of no working power supply, and the normally open contact inside the device is disconnected in the crane control loop, so that the crane cannot rise and fall operations, but the silent light alarm and fault code are displayed.
B. When the device is connected to the power supply, if there is a lack of phase C, the sound and light alarm will be issued, the fault code will be displayed, and the total power control contact and the control contact of the ascending circuit will be disconnected, and all operations will be prohibited.
c, in the working process of the crane motor, when a phase current is detected to be zero, sound and light alarm is issued, after a delay of a period of time (can be manually set), the fault code is displayed, and at the same time, the total power control contact and the rise circuit control contact are disconnected, and all operations are prohibited.

6. Short circuit protection
When the working current of any phase of the motor is greater than or equal to 600% of the rated current, the audible and visual alarm is issued. If it is not eliminated for 0.8 seconds, the fault code is displayed. At the same time, the total power control contact and the ascending circuit control contact are disconnected, and all operations are prohibited.

7. Blocked rotation protection
When the working current of any phase of the motor is ≥400% of the rated current, the audible and visual alarm is issued, and if it continues to be not eliminated within the starting time, the fault code is displayed, and the total power control contact and the rising circuit control contact are disconnected, and all operations are prohibited.

8. Three-phase imbalance protection When the current difference between any two phases is ≥60%, an audible and visual alarm is issued, if it is not eliminated for 5 seconds, the fault code is displayed, and the total power control contact and the control contact of the rising circuit are disconnected, and all operations are prohibited. 9. Undervoltage protection When the average voltage of the three-phase power supply is less than the undervoltage set value, the audible and visual alarm is issued, if it is not eliminated for 5 seconds, the fault code is displayed, and the total power control contact and the control contact of the rising circuit are disconnected, and all operations are prohibited. 10. Overvoltage protection When the average voltage of the three-phase power supply is greater than the overvoltage set value, sound and light alarm is issued, if it is not eliminated for 5 seconds, the fault code is displayed, and the total power control contact and the control contact of the rising circuit are disconnected, and all operations are prohibited. 11. Overcurrent protection Overcurrent protection action time for the inverse time characteristic protection, protection action time can be set according to user needs, the corresponding current multiple and protection action time characteristics of the value serial number are detailed in the manual.