BY CJ19-25 Series Modular Din Rail AC Magnetic Contactor Automatic Control Motor Reversing 380V 3 Pole

Main Specifications Data of CJ19-25 Series Intelligent Contactor 

Introduction of CJ19-25 Series Intelligent Contactor 

The Main Features of CJ19-25 Series Intelligent Contactor 

 1. Powerful three-phase motor control
BY CJ19-25 series provides precise three-phase contactor performance for industrial motor applications. Designed for 380V/3-pole operation, this series ensures reliable switching of high current loads up to 25A in automation systems, HVAC units and manufacturing equipment. Its AC electromagnetic contactor design utilizes electromagnetic coil technology for fast circuit connection/disconnection and minimizes arcing through integrated arc suppression. This reduces voltage spikes and keeps the motor running steadily during frequent starts/stops, which is critical for pumps, compressors and conveyor systems. Ideal for automatic motor reversing devices that require stable torque and direction control.

2. Enhance power quality protection
Mitigate harmonic distortion and voltage instability with our contactors’ power quality optimization capabilities. By minimizing switching transients and electromagnetic interference (EMI), it prevents waveform distortion that can disrupt sensitive electronic equipment. This is critical for facilities using inverters or rectifiers, where harmonic currents (e.g., 3rd, 5th, 7th) can reduce grid stability. The contactor’s low-resistance silver-tungsten alloy contacts reduce Joule heating, thereby suppressing voltage drops and unbalanced three-phase currents. Used in conjunction with harmonic mitigation solutions such as active power filters (APFs), THD-induced equipment failures can be fully prevented.

3. Industrial-grade reliability and lifespan
Designed for harsh environments, the contactor has a mechanical life of over 10 million operations, 10 times longer than standard relays. Its modular DIN rail design allows tool-free installation and seamless integration into control panels. Oil-immersed contacts and fully sealed construction protect against dust, moisture and corrosion, ensuring normal operation in temperatures ranging from -40°C to +85°C. With a short-circuit withstand rating of up to 90kA/1s, it protects motors from overload and phase failure, reducing downtime in factories, water treatment facilities and renewable energy sites.

4. Anti-harmonic switching technology
The zero-crossing optimization and anti-vibration architecture of our contactors can effectively combat harmonic pollution generated by non-linear loads (such as inverters and switching power supplies). The electromagnetic coil uses a silicon steel core and a short-circuit ring to suppress eddy currents, thereby reducing harmonic generation during switching. This minimizes current distortion (THiD < 3%) and prevents resonance amplification in the capacitor bank. For places with severe harmonics (such as data centers and laboratories), BY's harmonic control system can be used to achieve THD 148 level in accordance with standards.

5. Modular flexibility to provide customized solutions
This modular DIN rail contactor easily upgrades older systems. Its plug-in auxiliary contacts (NO/NC) support custom configurations for interlocking, signaling, or unbalanced load compensation. Use multiple contactors to build auto-commutation circuits, or combine with BY's reactive power compensation modules to achieve power factor (PF) correction >0.95. Its compact form factor saves 40% panel space compared to traditional contactors, while optional thermal protectors and surge suppressors provide customized protection against overvoltage and phase loss.

Working Conditions of CJ19-25 Series Intelligent Contactor 

Surrounding air temperature

• Applicable temperature range: -5℃ to +40℃
• The 24-hour average temperature must be kept at or below +35°C.

Altitude:

• The installation altitude shall not exceed 2000 meters.

Weather conditions

Shock and Tremor

• The product should be installed in an environment without significant shaking, shock and vibration to ensure optimal performance and extend service life.

Working Steps of CJ19-25 Series Intelligent Contactor 

Electromagnetic operation coil and magnetic core:
Its core operating principle relies on an electromagnetic system. When the control circuit applies voltage (usually 380V) to the AC contactor coil, a magnetic field is generated. This field magnetizes and attracts the movable ferromagnetic core (armature) to move toward the fixed core, overcoming the spring tension. This physical movement is the basic action to trigger the contact closure. The coil is designed for high efficiency in three-phase contactor applications, which keeps power consumption to a minimum, thereby indirectly improving the overall energy efficiency of the system. Reliable electromagnetic action ensures a fast response to motor starting, stopping or automatic control sequences in switchboards focused on power quality or circuit protection solutions.

Main current-carrying contacts and arc suppression:
The contactor's primary function is accomplished through its rugged three-pole silver alloy main contacts (one set per phase). When the electromagnetic coil is energized and the armature is attracted, these contacts close with high force, creating a low resistance path for the main load current (e.g., to the motor). Crucially, during the period when the contacts are open (de-energized), high currents can generate damaging arcs. Integrated arc extinguishing chambers use metal baffles to quickly cool, prolong, and extinguish the arc. This effective arc suppression is critical for contactors in motor control and circuit protection to prevent contact welding and minimize electrical noise that could interfere with sensitive equipment or affect local power quality.

Modular DIN rail mounting and auxiliary contacts:
Its key feature is its modular design, optimized for DIN rail mounting. This allows for fast, tool-free installation and easy integration with other power quality devices within the control panel, such as relays, miniature circuit breakers or harmonic mitigation devices. Contactors typically contain snap-on modular auxiliary contacts (NO/NC). These low-current signal contacts are mechanically connected to the movement of the main contactor. They provide the necessary status feedback (e.g. "main contact closed") to the control system for motor commutation, interlocking or sequencing control of PLCs in complex automatic control schemes for three-phase systems, thereby enhancing the monitoring and safety of circuit protection solutions.

Reverse interlock mechanism (applicable to reversing models):
In a motor reversing configuration, two CJ19-25 contactors are used (one for forward and one for reverse). Their operation is controlled by critical mechanical and/or electrical interlocks. This prevents both three-phase contactors from being energized simultaneously, which could result in a catastrophic phase-to-phase short. The interlock physically blocks the armature of the second contactor from closing if the first contactor is closed, and the electrical interlock is often integrated into the control circuit. This ensures safe, orderly, automatic control of motor direction changes, an essential requirement for applications such as conveyors or elevators, protecting the motor and upstream circuit protection devices from damage due to misoperation.

Size of CJ19-25 Series Intelligent Contactor