Explore our foundational refrigeration line engineered for high water absorption, mechanical durability, and electrical protection system integration.
In the modern commercial and industrial refrigeration landscape, continuous operations rely on the flawless integration of mechanical and electrical systems. Compressors represent the heart of these thermal systems, making them highly susceptible to phase failures, voltage instabilities, and thermal overloads. Thermal Overload Relays act as the vital electrical circuit protection shield, safeguarding compressor motors from irreversible burnout.
As a premier supplier in the HVAC/R domain, Ningbo Taojun Refrigeration Equipment Co., Ltd. bridge the gap between high-precision mechanical piping, custom filtering components, and electrical safeguarding systems. Combining our 38 years of experience in component design with state-of-the-art motor overload prevention technologies, we empower global OEMs and distributors with the resilient components needed to maintain high coefficient of performance (COP) and zero unplanned downtime.
Ningbo Taojun Refrigeration Equipment Co., Ltd. is located in Xiangshan, Ningbo, a strategic coastal transport hub. Founded in 1988, the company's predecessor was the Xiangshan Refrigeration Accessories Factory of Zhejiang University. This foundational relationship with one of China's most prestigious academic institutions established an early standard of technical rigour and engineering precision that defines our operations to this day.
Our flagship brand, "Lingshan" filters, has become a household name within the domestic refrigeration market, celebrated for custom geometries and unmatched durability. By 2021, Taojun was recognized as a national High-Tech Enterprise, solidifying our footprint in precision component manufacturing.
With official ISO9001:2015 quality management system certification, EU ROHS directive environmental compliance, and US UL listings, Taojun provides robust global supply guarantees to market leaders including Haier, Xinfei, Midea, Gree, Whirlpool, Electrolux, and Huarui.
How bimetallic and electronic overload protections integrate with advanced drying filters and condensers across key global regions.
In European markets, stringent efficiency regulations dictate motor and compressor protection standards. Under IEC 60947-4-1 compliance, overload protection relays must mitigate phase asymmetry and phase loss within 2 seconds. Meanwhile, in North America, NEMA compliance sets strict parameters for trip class (Class 10, Class 20, Class 30). By configuring bimetallic strips and digital ambient compensation sensors directly alongside core refrigeration elements, our mechanical components perform under controlled thermal envelopes.
Thermal bimetallic relays rely on expansion coefficients of laminated metal plates to physically trip the circuit. Our engineering department is pivoting towards Electronic Overload Relays (EOLRs). EOLRs leverage current transformers to measure exact mechanical load parameters. This transition minimizes energy leakage as heat within the control box, helping large cold storages reduce system resistance, optimize refrigerant flow, and support smart diagnostics.
Fluctuating grid infrastructure in developing economies exposes refrigeration systems to voltage sags and spikes. Our integrated solutions focus on building resilience against these conditions. By utilizing high-purity copper housings, molecular sieves with water absorption metrics ≥ 20%, and thermal relay setups configured for automatic or manual reset options, we safeguard industrial cooling systems from early motor failure under poor power grids.
Ningbo Taojun's competitive edge is anchored in our advanced manufacturing ecosystems and raw material vertical integration. Key raw materials—such as high-end ITO film ensuring zero shrinkage and liquid crystal spacers imported from Japan, along with thermal-resistant adhesives from Europe—must pass rigorous incoming inspection protocols.
Our core manufacturing facility operates under the Manufacturing Execution System (MES), enabling real-time tracing of component assembly. Advanced automated testing includes helium mass spectrometer leak detection to guarantee zero-leakage joints, CCD visual dimensional checks, and automatic copper pipe cutting systems. With a target defect rate of less than 0.05%, Taojun stands as a globally verified Tier-1 OEM/ODM partner.
A global brand is supported by a strong corporate culture: Honesty, Innovation, Responsibility, and Cooperation.
Established as the Xiangshan Refrigeration Accessories Factory of Zhejiang University, setting the course for science-backed manufacturing.
Relocated to custom facility plants to ramp up national domestic demand for copper filters and access valves.
Introduced MES workshop management systems, mapping batch control and tracking quality across components.
Officially established Ningbo Taojun Refrigeration Equipment Co., Ltd. and developed customized condenser and valve product portfolios.
Upgraded to cleanrooms for complex cooling assemblies, targeting carbon-neutral and eco-friendly packaging initiatives.
Providing official compliance verification, sustainable manufacturing practices, and structural product safety approvals.
ISO 9001 Quality Certification
Certified Scope of Manufacturing
US UL Safety Listed
RoHS Environmental Conformity
Verification of accreditation can be queried at the official CNCA database (www.cnca.gov.cn) under registration number 41325Q00065R0S.
Where our copper accessories, filter driers, and electrical protection systems integrate globally.
Explore our highly-conductive brass fittings, control units, and brazing materials for complete system installations.
Get authoritative technical insights directly from our senior engineering team.
Bimetallic overload relays monitor the active current consumed by the refrigeration compressor's motor. They feature bimetallic strips inside each phase path. When an overcurrent or prolonged high mechanical load occurs, the thermal energy generated bends the bimetallic strips (due to differing thermal expansion rates of the two metals). This mechanical deflection physically triggers a contact set to break the control circuit, turning off the compressor contactor before the motor coils exceed their rated insulation temperature limit.
Our copper filter driers utilize a premium 3A molecular sieve desiccant core. It features a water absorption capability of ≥20% of its dry weight. The 3A molecular sieve selectively adsorbs water molecules while leaving refrigerants like R134a, R22, and R600a untouched, preventing capillary tube freezing and chemical acid formation within the compressor.
Unlike thermal relays that rely on bimetallic strips heated by line current, electronic overload relays (EOLRs) utilize internal current transformers (CTs) to digitally read the current. EOLRs offer much higher accuracy, generate almost no internal heat (preventing ambient temperature de-rating), and provide faster trip curves under severe faults like phase failure or locked rotor conditions.
Refrigeration equipment mechanical rooms often experience high ambient temperatures. A standard, uncompensated thermal overload relay might trip prematurely under high ambient temperatures even if the compressor motor current is normal. Compensated overload relays feature a secondary, non-current-carrying bimetallic strip that bends in the opposite direction to cancel out the effect of external ambient heat, ensuring the relay trips solely in response to motor overcurrent.
All finned tube condensers and access valves undergo dual helium leak detection and high-pressure nitrogen testing (up to 4.5 MPa depending on the specification) to ensure high-pressure seal integrity. Additionally, components are subjected to a 500-hour damp heat test to verify corrosion resistance in marine or high-humidity tropical climates.
Supported by our R&D center of engineers and our MES system, we accommodate custom requirements down to a 500-unit MOQ. Partners can share targeted specifications—such as precise piping dimensions, custom capillary configurations, or specific trip thresholds—and our engineering team will compile CAD design validations within 48 hours.
Leveraging our facility location in Xiangshan, Ningbo, we utilize direct access to Ningbo-Zhoushan Port. Standard production cycles take 15 to 25 days depending on the volume, with rush capabilities supported by our automated manufacturing lines. Urgent replacements can be dispatched globally within 72 hours via air freight partners.
Taojun