---
title: "Refrigerator Compressor Thermal Overload Protector"
industry: "Manufacture of Domestic Appliances"
verification_protocol:
  urn: "URN:CNFX:ME:REFRIGERATOR_COMPRESSOR_THERMAL_OVERLOAD_PROTECTOR"
  data_integrity_hash: "8ac868670798a1e5d0c931eb2add3f5a"
  source_authority: "https://cnfx.com"
  strict_mode: true
source_identity:
  provider: "CNFX Industrial Knowledge Graph"
  index_version: "2026.Q1-Universal"
  authority_id: "URN:CNFX:ME:REFRIGERATOR_COMPRESSOR_THERMAL_OVERLOAD_PROTECTOR"
  data_source_uri: "https://cnfx.com/llms/industry/manufacture-domestic-appliances/product/refrigerator-compressor-thermal-overload-protector.md"
  official_resource_url: "https://cnfx.com/industry/manufacture-domestic-appliances/product/refrigerator-compressor-thermal-overload-protector"
  is_verified_logic: true
attributes:
  primary_spec:
    status: "config-dependent"
    typical_range: "70-150°C bimetallic strip actuation temperature"
    unit: "A"
  secondary_spec:
    status: "config-dependent"
    typical_range: "70-150°C bimetallic strip actuation temperature"
    unit: "°C"
engineering_limits:
  max_safe_operating_point:
    value: 165
    unit: "°C"
    consequence: "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"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Compressor locked rotor current (7-10× rated current)"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Current-limiting PTC thermistor in series with compressor windings"
  - node_2:
      trigger: "Ambient temperature exceeding 55°C with 85% relative humidity"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Hermetic sealing with nitrogen-filled epoxy encapsulation"
bom_nodes:
  bimetal-disc:
    type: "component"
    urn: "URN:CNFX:ME:BIMETAL_DISC"
    interface_type: "physical-logic-coupled"
  contact-assembly:
    type: "part"
    urn: "URN:CNFX:ME:CONTACT_ASSEMBLY"
    interface_type: "physical-logic-coupled"
  terminal-pins:
    type: "component"
    urn: "URN:CNFX:ME:TERMINAL_PINS"
    interface_type: "physical-logic-coupled"
  protective-housing:
    type: "component"
    urn: "URN:CNFX:ME:PROTECTIVE_HOUSING"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
  - standard: "ISO 9001:2015 - QUALITY MANAGEMENT SYSTEMS"
    scope: "Verified Engineering Specification"
url: "https://cnfx.com/llms/industry/manufacture-domestic-appliances/product/refrigerator-compressor-thermal-overload-protector.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "d826af9323a7b9c49ce76df0617a681756551a66f5067f91f81175bb42f5ca6f"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Refrigerator Compressor Thermal Overload Protector

## 1. Technical Definition
Thermal protection device for refrigerator compressor motors

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **70-150°C bimetallic strip actuation temperature**. Failure boundary: **165°C continuous exposure causing bimetallic element permanent deformation**, Mechanism: **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**.

### 2.1 Analytical Physics Model
Governed by the **Joule Heating & Thermal Resistance**:

> **Primary Equation**: $P = I^2 R = \frac{V^2}{R}$  
> **Engineering Impact**: Governs heating element sizing for shrink tunnels/sealers.

| Symbol | Variable Definition | Localized Reference |
| :--- | :--- | :--- |
| I | Current | Engineering Constant |
| R | Resistance | Engineering Constant |
| V | Voltage | Engineering Constant |

### 2.2 FMEA (Failure Mode & Effects Analysis)
| Event Trigger | Severity | Failure Mode | Mitigation Strategy |
| :--- | :--- | :--- | :--- |
| Compressor locked rotor current (7-10× rated current) | 8 | Bimetallic element weld fusion at contact points | Current-limiting PTC thermistor in series with compressor windings |
| Ambient temperature exceeding 55°C with 85% relative humidity | 8 | Corrosion-induced contact resistance increase to &gt;50 mΩ | Hermetic sealing with nitrogen-filled epoxy encapsulation |

## 3. Key Technical Parameters
| Parameter | Value | Unit | Status |
| :--- | :--- | :--- | :--- |
| primary_spec | Config-dependent | A | Verified |
| secondary_spec | Config-dependent | °C | Verified |

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)
- [Contact Assembly](https://cnfx.com/llms/industry/electrical-equipment-manufacturing/product/contact-assembly.md) `(Standalone System)`

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **Temperature Calibration Chamber**, **Automatic Coil Winding Machine**, **Hermetic Sealing Tester**  
**Downstream Applications**: Domestic Refrigerators, Commercial Refrigeration Units, Air Conditioning Systems  

## 5. Engineering Risks & FAQ
- **Caution**: 
- **Caution**: 
- **Caution**: 

### Q: What is the purpose of a thermal overload protector in a refrigerator compressor?
**A**: The thermal overload protector safeguards refrigerator compressor motors by automatically disconnecting power when excessive heat is detected, preventing motor burnout and ensuring safe operation.

### Q: How does the bimetal disc mechanism work in this protector?
**A**: 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.

### Q: What are the advantages of silver-cadmium oxide contacts in this device?
**A**: 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.

## 6. Manufacturing Compliance
- ISO 9001:2015 - QUALITY MANAGEMENT SYSTEMS

---
### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Refrigerator Compressor Thermal Overload Protector](https://cnfx.com/industry/manufacture-domestic-appliances/product/refrigerator-compressor-thermal-overload-protector)**

### 🌐 Knowledge Graph Topology
> **Node Status**: Verified Engineering Spec
> **Connectivity**: Linked to **4** standalone system nodes
> **Global Context**: Part of a 5,814 node industrial cluster within the CNFX Graph

> **Reference ID**: REFRIGERATOR_COMPRESSOR_THERMAL_OVERLOAD_PROTECTOR | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: 7c6a696b
