The applications of micro-coils in tower cranes

The applications of micro-coils in tower cranes are mainly reflected in the electrical control system, particularly playing a crucial role in components such as DC contactors and relays. The specifics are as follows:

Applications in DC Contactors

Arc Extinction by Magnetic Blowout: DC contactors in tower cranes need to address the arc-drawing phenomenon that occurs when the contacts interrupt DC current. The micro-coil (magnetic blowout coil) generates a magnetic field when the contacts open, stretching the arc length and increasing the arc voltage drop, thereby achieving rapid arc extinction. This function ensures the electrical safety of the crane during frequent starts and stops, preventing contact erosion or short-circuit risks caused by arcs.
Model Adaptation: Commonly used DC contactor models include CZ0 and CZ0-40C. The CZ0 type DC contactor is available in various current ratings and comes in both single-pole and double-pole versions. When selecting a DC contactor, it is essential to ensure the capacity matching of the magnetic blowout coil to guarantee arc-extinguishing performance.

Applications in Relays

Overcurrent Protection: The micro-coil in an overcurrent relay is used to protect the motor from overload and short circuits. When a short circuit or overload occurs in the motor, the magnetic force generated by the micro-coil pulls up the armature, cutting off the control circuit and thus protecting the motor.
Time Control: The micro-coil in a time relay is used to achieve delayed action functionality. After receiving a conditioning signal, the micro-coil controls the working contacts to act after a certain period, meeting specific control requirements.