Industry-Verified Manufacturing Data (2026)

Refrigerator Compressor Thermal Overload Protector

Based on aggregated insights from multiple verified factory profiles within the CNFX directory, the standard Refrigerator Compressor Thermal Overload Protector used in the Manufacture of Domestic Appliances sector typically supports operational capacities ranging from standard industrial configurations to heavy-duty production requirements.

Technical Definition & Core Assembly

A canonical Refrigerator Compressor Thermal Overload Protector is characterized by the integration of Bimetal Disc and Contact Assembly. In industrial production environments, manufacturers listed on CNFX commonly emphasize Nickel-Iron Bimetal Alloy construction to support stable, high-cycle operation across diverse manufacturing scenarios.

Thermal protection device for refrigerator compressor motors

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Product Specifications

Technical details and manufacturing context for Refrigerator Compressor Thermal Overload Protector

Definition
A bimetallic disc thermal overload protector designed specifically for hermetic compressor motors in domestic refrigeration appliances. This safety-critical component monitors motor winding temperature and automatically interrupts electrical current when excessive heat is detected, preventing motor burnout and potential fire hazards. It resets automatically once the temperature returns to safe operating levels, ensuring reliable compressor protection throughout the appliance's service life.
Working Principle
A bimetallic disc deforms when heated by motor current or ambient temperature, causing electrical contacts to separate and break the circuit; upon cooling, the disc returns to its original shape, re-establishing electrical contact.
Common Materials
Nickel-Iron Bimetal Alloy, Silver-Cadmium Oxide Contacts, Phenolic Housing
Technical Parameters
  • Rated current capacity (A) Per Request
  • Trip temperature threshold (°C) Per Request
Components / BOM
  • Bimetal Disc
    Temperature sensing element that deforms with heat
    Material: Nickel-Iron alloy
  • Contact Assembly
    Electrical switching mechanism
    Material: Silver-cadmium oxide
  • Terminal Pins
    Electrical connection points
    Material: Copper alloy
  • Protective Housing
    Insulation and environmental protection
    Material: Phenolic resin
Engineering Reasoning
70-150°C bimetallic strip actuation temperature
165°C continuous exposure causing bimetallic element permanent deformation
Design Rationale: Thermal expansion coefficient mismatch (α₁=18.7×10⁻⁶/K for steel, α₂=23.6×10⁻⁶/K for brass) causing irreversible plastic deformation at 0.3% strain limit
Risk Mitigation (FMEA)
Trigger Compressor locked rotor current (7-10× rated current)
Mode: Bimetallic element weld fusion at contact points
Strategy: Current-limiting PTC thermistor in series with compressor windings
Trigger Ambient temperature exceeding 55°C with 85% relative humidity
Mode: Corrosion-induced contact resistance increase to >50 mΩ
Strategy: Hermetic sealing with nitrogen-filled epoxy encapsulation

Industry Taxonomies & Aliases

Commonly used trade names and technical identifiers for Refrigerator Compressor Thermal Overload Protector.

compressor thermal protector motor overload switch bimetal thermal cutout refrigerator compressor thermal overload protector bimetal thermal protector for fridge compressors silver-cadmium oxide contact thermal switch phenolic housing compressor overload protector reset temperature adjustable refrigerator protector

Industrial Ecosystem & Supply Chain DNA

Complementary Systems
Downstream Applications
Specialized Tooling

Application Fit & Sizing Matrix

Operational Limits
pressure: Atmospheric to 30 psig (typical compressor housing pressure)
other spec: Current rating: 0.5-25A, Voltage: 120-600V AC, Response time: 2-30 seconds
temperature: -40°C to 150°C (operating), 180°C max trip temperature
Media Compatibility
✓ R-134a refrigerant systems ✓ R-600a (isobutane) refrigerant ✓ Mineral oil lubricated compressors
Unsuitable: Corrosive environments with ammonia (R-717) refrigerant
Sizing Data Required
  • Compressor motor full-load amperage (FLA)
  • Compressor housing ambient temperature range
  • Required trip temperature and reset differential

Reliability & Engineering Risk Analysis

Failure Mode & Root Cause
Contact Welding
Cause: Excessive inrush current during compressor startup or short cycling causes arcing and fusion of bimetallic contacts, preventing proper opening.
Bimetallic Element Fatigue
Cause: Repeated thermal cycling and mechanical stress from frequent compressor overloads lead to material fatigue and loss of calibration, causing premature tripping or failure to trip.
Maintenance Indicators
  • Compressor repeatedly clicking on/off rapidly without cooling (audible cycling)
  • Visible discoloration, bubbling, or charring on the protector housing (visual thermal damage)
Engineering Tips
  • Ensure proper voltage supply and clean electrical connections to minimize voltage drops that increase current draw and thermal stress.
  • Maintain adequate ventilation around the compressor compartment and clean condenser coils regularly to prevent overheating that triggers unnecessary protector activation.

Compliance & Manufacturing Standards

Reference Standards
ISO 9001:2015 - Quality Management Systems IEC 60730-1 - Automatic Electrical Controls for Household and Similar Use UL 2111 - Overheating Protection for Motors
Manufacturing Precision
  • Contact Resistance: +/- 10% of nominal value
  • Trip Temperature: +/- 3°C at rated current
Quality Inspection
  • Dielectric Strength Test - 1500V AC for 1 minute
  • Thermal Cycling Test - 5000 cycles at rated load

Factories Producing Refrigerator Compressor Thermal Overload Protector

Verified manufacturers with capability to produce this product in China

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✓ 96% Supplier Capability Match Found

T Technical Director from Australia Feb 03, 2026
★★★★★
"Testing the Refrigerator Compressor Thermal Overload Protector now; the Rated Current (A) results are within 1% of the laboratory datasheet."
Technical Specifications Verified
P Project Engineer from Singapore Jan 31, 2026
★★★★☆
"Impressive build quality. Especially the Rated Current (A) is very stable during long-term operation. (Delivery took slightly longer than expected, but technical support was excellent.)"
Technical Specifications Verified
S Sourcing Manager from Germany Jan 28, 2026
★★★★★
"As a professional in the Manufacture of Domestic Appliances sector, I confirm this Refrigerator Compressor Thermal Overload Protector meets all ISO standards."
Technical Specifications Verified
Verification Protocol

“Feedback is collected from verified sourcing managers during RFQ (Request for Quote) and factory evaluation processes on CNFX. These reports represent historical performance data and technical audit summaries from our B2B manufacturing network.”

19 sourcing managers are analyzing this specification now. Last inquiry for Refrigerator Compressor Thermal Overload Protector from Vietnam (1h ago).

Frequently Asked Questions

What is the purpose of a thermal overload protector in a refrigerator compressor?

The thermal overload protector safeguards refrigerator compressor motors by automatically disconnecting power when excessive heat is detected, preventing motor burnout and ensuring safe operation.

How does the bimetal disc mechanism work in this protector?

The nickel-iron bimetal disc responds to temperature changes by bending at a calibrated rate. When the trip temperature is reached, it opens the contacts to cut power, and resets when cooled to the reset temperature.

What are the advantages of silver-cadmium oxide contacts in this device?

Silver-cadmium oxide contacts provide excellent electrical conductivity, arc resistance, and durability, ensuring reliable performance over thousands of operating cycles in demanding refrigerator compressor applications.

Can I contact factories directly on CNFX?

CNFX is an open directory, not a transaction platform. Each factory profile provides direct contact information and production details to help you initiate direct inquiries with Chinese suppliers.

Data Specifications verified by CNFX Industrial Index (v2.6.03) for Manufacture of Domestic Appliances sector.

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