Engineered to withstand harsh electrical switching cycles, mechanical stress, and volatile environments.
Definite Purpose (DP) contactors are the unsung heart of modern industrial, commercial, and residential HVAC systems. Tasked with handling extreme start-stop switching operations, these electromagnetic switches direct the high-amperage electrical current flowing directly to heavy inductive loads like compressors, condenser fans, and blower motors.
With urbanization rapidly accelerating in the global south and smart-grid integrations becoming mandatory across North America and Europe, the demand for highly reliable, surge-resistant AC contactors has exploded. Today’s procurement teams require components capable of withstanding massive inrush currents (up to 6 times the Full Load Amperes, or FLA) while maintaining minimal contact bounce to prolong the operational lifespan of expensive compressor systems.
Engineering heavy-duty contactors, copper filter driers, and high-efficiency refrigeration accessories.
Our contactors are designed using premium silver-tin oxide (AgSnO2) contacts, providing superior anti-welding properties and minimizing arc damage during severe inductive switching.
TAOJUN copper filter driers feature high-purity copper shells welded via argon arc processes, packed with 3A molecular sieves providing moisture absorption ≥20% to safeguard the compressor.
Integrated varistors and suppression circuits reduce electromagnetic interference (EMI) and protect modern residential and industrial microcontroller units (MCUs) from coil back-EMF spikes.
Sourcing Definite Purpose contactors and filtration systems from China offers unparalleled strategic advantages in logistics speed, material scale, and structural cost optimizations. At Ningbo Taojun Refrigeration Equipment Co., Ltd., we combine the localized supply of premium electrical-grade copper, precision tooling, and high-conductivity silvers with advanced European technologies.
By establishing strategic joint laboratories with local prestigious research universities, we implement rigorous product updates that would normally take years. This ecosystem enables us to keep lead times to a minimum and quickly adapt to custom configuration requests, ensuring our international OEM and distribution clients stay ahead in their markets.
Established in 1988, Ningbo Taojun Refrigeration has been a domestic leader in researching and fabricating premium HVAC electrical controllers and filtration parts. Experience our automated processing facility firsthand.
Year of Incorporation
Countries Exported to Globally
Ph.D. & Professor Level R&D Engineers
Continuous High-Humidity Aging Tests
35 years of engineering breakthroughs in HVAC refrigeration controls and molecular filtration components.
Originating as the Xiangshan Refrigeration Accessories Factory of Zhejiang University. Our design foundation was formed through rigorous academic collaborations, laying the groundwork for custom thermodynamic and electromagnetic accessories.
Implementation of the MES (Manufacturing Execution System) intelligent workshop management program, transitioning all key production paths to automatic tracking and data logging systems.
Expansion to custom IoT Definite Purpose contactor testing and automated helium mass spectrometer leak detection lines, ensuring absolute durability for next-generation climate systems.
Ensuring system durability and energy efficiency across commercial, marine, and extreme climates.
Single and double-pole definite purpose contactors are used to cycle compressor loads, while copper filter driers protect capillaries from freezing due to moisture intrusion.
High-reliability contacts manage heavy three-phase starting currents, preventing premature contact failure under high switching frequencies.
Our heavy-duty switch solutions work alongside robust filters and accumulators to protect system compressors during continuous, low-temperature cycles.
Specially coated magnetic coils and high-purity copper shells provide superior corrosion resistance against humid, salty maritime environments.
Taojun Refrigeration maintains an uncompromising commitment to international standards. Our manufacturing processes are fully certified to GB/T19001-2016/ISO9001:2015 (Registration No.: 41325Q00065R0S) for the design and production of precision refrigeration components including filter driers, condensers, and access valves.
To ensure seamless compatibility and safety compliance globally, our product families carry UL, CE, and EU RoHS environmental directives. Our incoming materials, from Japanese-imported ITO film to European insulation compounds, undergo comprehensive testing before entering production.
UL Standards Compliance
RoHS Environmental
European CE Approval
ISO9001 Registration
National Hi-Tech Status
Supporting global brands with high-performance manufacturing, design customization, and reliable engineering support.
We work closely with clients to review system specifications and address potential field failure modes. With 15+ years of pump and compressor engineering experience, our team helps select the right coil configurations and terminal layouts for your application.
We provide full technical support throughout the operational lifecycle of our products, backed by a comprehensive one-year replacement warranty on all standard catalog components.
Answers to common questions about definite purpose contactor design, selection, and sourcing.
A 1-pole contactor switches only one live line, leaving the neutral line constantly connected. This design is common in residential systems but carries a minor electrical risk as the compressor terminals remain energized even when the system is off. A 2-pole contactor switches both lines, fully isolating the motor or compressor. A 3-pole contactor is used for heavy-duty commercial three-phase equipment (such as 380V-480V systems) to balance phase loads and prevent single-phase failure modes.
Full Load Amperes (FLA) represents the continuous current drawing capability of the compressor under normal operating conditions. Locked Rotor Amperes (LRA) represents the initial inrush current drawn when the compressor starts from a complete standstill, which is significantly higher. A contactor must have an LRA rating that exceeds the compressor's startup inrush current to prevent the contacts from welding together.
We use 3A molecular sieves, which have an effective pore size of approximately 3 Angstroms. This specific size is chosen because it easily adsorbs water molecules (which have a kinetic diameter of 2.65 Å) while excluding common HCFC/HFC refrigerant molecules (such as R134a, R32, R410A) and lubricant mixtures. Selecting the correct pore size prevents competitive adsorption and system clogging.
Contactor chatter is often caused by voltage fluctuations in the control circuit or dirt build-up in the magnetic armature gap. This rapid oscillation can quickly burn out the contact faces. We address this by using high-tension, precision coil windings and dust-sealed housings, which maintain a strong magnetic hold even during minor system voltage drops.
Every filter drier and accumulator undergoes rigorous leak testing. We utilize high-sensitivity helium mass spectrometer leak detectors capable of detecting microscopic leaks down to 1x10^-9 Pa·m³/s. This ensures long-term hermetic seal integrity in high-vibration environments.
Direct supply of certified components for global distribution networks and OEM system integrators.
Taojun