Small Household Appliance Circuit Safety Protection SETsafe | SETfuse Solutions and Products

This article focuses on circuit safety protection for small household appliances, covering the following areas:

Over-temperature Protection for Heating Resistor --- Over-temperature Protection

Over-temperature Protection for Heating Tube --- Over-temperature Protection

Over-temperature Protection for Heating Coil --- Over-temperature Protection

Over-temperature Protection for PI Heating Film --- Over-temperature Protection

Over-temperature Protection for PTC Heater --- Over-temperature Protection

Over-temperature Protection for Motor --- Over-temperature Protection

Over-current Protection for Power Supply --- Over-current Protection

Lithium Battery Overcharge/Over-discharge Protection --- Active Protection

Overview

Small household appliances are compact, low-power devices designed for daily household use to enhance convenience and comfort. They span various categories, including kitchen appliances (e.g., rice cookers, microwaves, induction cookers, pressure cookers, ovens, air fryers, juicers, blenders, soy milk makers, coffee machines, bread makers, electric kettles, food processors, and compact dishwashers), cleaning appliances (e.g., vacuum cleaners, robotic vacuums, steam mops, air purifiers, humidifiers, and dehumidifiers), personal care devices (e.g., electric shavers, hair dryers, electric toothbrushes, beauty devices, hair clippers, and epilators), and lifestyle aids (e.g., electric fans, heaters, irons, garment steamers, sewing machines, smart speakers, mosquito repellents, electronic scales, clocks, thermohygrometers, portable power banks, and mini projectors). These appliances are user-friendly, energy-efficient, portable, and some feature smart controls or voice interaction, making them integral to modern households.

According to market research, the global small appliance market is projected to reach USD 118.12 billion to USD 212.3 billion by 2025, with estimates suggesting a market size of approximately USD 186.44 billion to USD 200 billion by 2030, depending on economic conditions, consumer trends, and technological advancements (data sourced from the internet for reference only).

Why Use Disposable Thermal Fuses for Over-Temperature Protection in Heating Resistors

Reasons

Prevent Safety Incidents from Overheating

Heating resistors (e.g., heating tubes or wires) generate high temperatures during operation. Malfunctions such as thermostat failure, fan stoppage, or poor heat dissipation can cause abnormal temperature rises, leading to fires, equipment damage, or personal injury. Disposable thermal fuses (also known as thermal cutoffs or thermal protectors) melt and disconnect the power supply when the temperature reaches a preset danger threshold, preventing further temperature escalation.

High Reliability and Fast Response

Disposable thermal fuses operate based on the physical properties of metal alloy melting points, independent of electronic components or software. This ensures reliable activation even in extreme conditions (e.g., circuit board failure) with rapid response times.

Non-Resettable for Enhanced Safety

Once triggered, disposable thermal fuses cannot be reset, ensuring that equipment experiencing severe overheating cannot be restarted without inspection or fuse replacement. This prevents continued operation with unresolved safety hazards.

Ease of Integration

Their compact design allows easy installation near heating resistors, enabling direct temperature sensing, which suits the space-constrained designs of small appliances.

Standards and Requirements

National Standards

GB 4706.1-2005 (*Household and Similar Electrical Appliances – Safety, Part 1: General Requirements*), equivalent to IEC 60335-1, mandates effective over-temperature protection for appliances under abnormal conditions (e.g., thermostat failure) to prevent fire, electric shock, or other hazards. Specific standards, such as GB 4706.19 (for liquid heaters) or GB 4706.23 (for hair dryers), may further require thermal fuses or equivalent over-temperature protection devices.

Mandatory Requirements

In China, small appliances must pass CCC (China Compulsory Certification) based on the GB 4706 series. If heating resistors pose an overheating risk, certification bodies typically require disposable thermal fuses or equivalent protection devices. Non-compliance results in certification failure.

International Standards

IEC 60335 series standards require over-temperature protection for household appliances. Certifications in Europe (CE) and the U.S. (UL) have similar requirements, and disposable thermal fuses are widely adopted due to their reliability.

Disposable thermal fuses are used in heating resistors to prevent safety risks from overheating. Their non-resettable nature and high reliability make them a common choice. In China, GB 4706 standards and CCC certification indirectly mandate over-temperature protection, with thermal fuses being the industry standard. For specific standard clauses or product requirements, refer to GB 4706 standards or consult CCC certification bodies.

Why Use Disposable Thermal Fuses for Over-Temperature Protection in Heating Tubes

Reasons

Prevent Safety Incidents from Overheating

Heating tubes in appliances (e.g., electric kettles, heaters, or hair dryers) generate high temperatures. Failures such as thermostat malfunctions, poor heat dissipation, or fan stoppage can cause excessive temperature rises, leading to fires, equipment damage, or injury. Disposable thermal fuses melt and cut off power when temperatures exceed safe limits, preventing further escalation.

High Reliability and Fast Response

Operating on the physical principle of metal alloy melting, thermal fuses are independent of electronic components, ensuring reliable and rapid activation even in extreme conditions.

Non-Resettable for Enhanced Safety

Their non-resettable design ensures that equipment cannot resume operation after severe overheating without inspection or fuse replacement, mitigating unresolved risks.

Ease of Integration

Compact and easily installed near heating tubes, thermal fuses directly sense temperature changes, fitting the compact designs of small appliances.

Standards and Requirements

National Standards

GB 4706.1-2005 requires over-temperature protection for appliances under abnormal conditions. Specific standards, such as GB 4706.19 (liquid heaters) or GB 4706.23 (hair dryers), may further mandate over-temperature protection for heating elements. Disposable thermal fuses are commonly used to meet these requirements.

Mandatory Requirements

CCC certification, based on GB 4706 standards, requires over-temperature protection for heating tubes. Certification bodies typically mandate disposable thermal fuses or equivalent devices to ensure compliance.

International Standards

IEC 60335 series and certifications like UL and CE require over-temperature protection, with thermal fuses being a widely adopted solution due to their reliability and cost-effectiveness.

Disposable thermal fuses prevent overheating-related fires or damage in heating tubes. Their reliability, fast response, and non-resettable nature make them ideal. In China, GB 4706 standards and CCC certification indirectly mandate their use, making them an industry standard. Refer to GB 4706 standards or consult CCC certification bodies for specific requirements.

Why Use Disposable Thermal Fuses for Over-Temperature Protection in Heating Coils

Reasons

Prevent Overheating-Related Fires or Damage

Heating coils generate high temperatures during operation. Faults like thermostat failure, poor heat dissipation, or circuit anomalies can cause temperature spikes, risking fires or equipment damage. Thermal fuses permanently disconnect the circuit when temperatures exceed safe thresholds, ensuring safety.

Non-Resettable Protection

Once melted, thermal fuses cannot be reset, preventing equipment restart until the issue is resolved, thus avoiding repeated risks.

Address Multiple Abnormal Conditions

Thermal fuses protect against thermostat failure, overload, short circuits, or design flaws, serving as a final safety barrier.

Compliance with Safety Standards

Global and regional standards mandate over-temperature protection for heating elements. Thermal fuses provide a reliable, cost-effective solution to meet these requirements.

Standards and Requirements

International Standards

IEC 60335-1

Requires over-temperature protection for heating elements, with thermal fuses commonly used to meet abnormal operation and protection clauses. 

IEC 60730-1

Specifies performance, temperature accuracy, and reliability testing for thermal fuses.

National Standards

GB 4706.1

Mandates reliable over-temperature protection for heating elements. 

GB/T 9816

Specifies technical requirements for thermal fuses, including rated temperature, accuracy, and durability. 

GB/T 14536

Covers performance and testing of thermal fuses as protective devices.

Mandatory Requirements

CCC certification, based on GB 4706 standards, requires over-temperature protection for heating coils. Thermal fuses are a common choice, and certification tests verify their effectiveness under abnormal conditions. Non-compliant products are prohibited from sale in China.

Other Regional Standards

UL 873 (U.S.)

Specifies safety requirements for temperature control and protection devices. 

EN 60335-1 (EU)

Similar to IEC 60335-1, requires over-temperature protection. 

CE and UL certifications, as well as Japan’s PSE and Australia’s SAA, often rely on IEC or equivalent standards, with thermal fuses widely used.

Disposable thermal fuses in heating coils prevent overheating-related safety risks and comply with standards like IEC 60335-1 and GB 4706.1. In China, CCC certification mandates over-temperature protection, with thermal fuses as a standard solution. Specific requirements can be found in GB 4706 standards or through CCC certification bodies.

Why Use Disposable Thermal Fuses for Over-Temperature Protection in PI Heating Films

Reasons

Prevent Safety Incidents from Overheating

Polyimide (PI) heating films, used in appliances like heaters or therapeutic devices, generate high temperatures. Faults such as thermostat failure or poor heat dissipation can lead to fires or damage. Thermal fuses cut off power when temperatures exceed safe limits.

High Reliability and Fast Response

Based on metal alloy melting, thermal fuses are reliable and fast, even in extreme conditions, making them suitable for PI heating films’ high-temperature environments.

Non-Resettable for Safety

Their non-resettable nature ensures equipment cannot restart without addressing the overheating issue, enhancing long-term safety.

Suitability for PI Heating Films

PI films require compact, integrated protection devices. Thermal fuses are small, easily installed near the film, and directly sense temperature changes.

High Reliability

Their passive protection mechanism ensures stable performance in high-temperature environments.

Standards and Requirements

National Standards

GB 4706.1-2005 mandates over-temperature protection for appliances, including those with PI heating films. Specific standards (e.g., GB 4706.8 for heating pads) may further require reliable protection devices.

Mandatory Requirements

CCC certification, based on GB 4706 standards, requires over-temperature protection for PI heating films. Thermal fuses are a common solution to meet these requirements.

International Standards

IEC 60335 series and certifications like UL and CE mandate over-temperature protection, with thermal fuses widely used for PI heating films.

Disposable thermal fuses prevent overheating risks in PI heating films, with their reliability, fast response, and compact design making them ideal. In China, GB 4706 standards and CCC certification indirectly mandate their use. Refer to GB 4706 standards or consult CCC certification bodies for specific requirements.

Why Use Disposable Thermal Fuses for Over-Temperature Protection in PTC Heaters

Reasons

Address Overheating Risks in Abnormal Conditions

Despite PTC heaters’ self-limiting properties, faults like poor heat dissipation or fan failure can cause localized overheating, risking fires or damage. Thermal fuses cut off power when temperatures exceed safe limits.

High Reliability and Fast Response

Operating on physical principles, thermal fuses ensure reliable and rapid activation, even in extreme conditions.

Non-Resettable for Safety

Their non-resettable design prevents restart until the issue is resolved, ensuring long-term safety.

Suitability for PTC Heaters

Compact thermal fuses integrate easily near PTC elements, directly sensing temperature changes in space-constrained appliances.

High Reliability

Their passive mechanism ensures stable performance in high-temperature or abnormal conditions.

Standards and Requirements

National Standards

GB 4706.1-2005 mandates over-temperature protection for appliances with PTC heaters. Specific standards (e.g., GB 4706.23 for hair dryers) may further require protection devices.

Mandatory Requirements

CCC certification requires over-temperature protection for PTC heaters, with thermal fuses as a common solution.

International Standards

IEC 60335 series and UL/CE certifications mandate over-temperature protection, with thermal fuses widely used.

Disposable thermal fuses prevent overheating risks in PTC heaters, with their reliability and compact design making them suitable. In China, GB 4706 standards and CCC certification indirectly mandate their use. Refer to GB 4706 standards or consult CCC certification bodies for specific requirements.

Why Use Disposable Thermal Fuses for Over-Temperature Protection in Motors

Reasons

Prevent Safety Incidents from Overheating

Motors in appliances like fans or blenders can overheat due to overload, stalling, or poor heat dissipation, risking insulation damage, fires, or electric shock. Thermal fuses cut off power when temperatures exceed safe limits.

High Reliability and Fast Response

Operating on physical principles, thermal fuses ensure reliable and rapid activation, even in extreme conditions.

Non-Resettable for Safety

Their non-resettable design prevents restart until the issue is resolved, ensuring long-term safety.

Suitability for Motors

Compact thermal fuses integrate easily into motor windings or nearby, sensing temperature changes in space-constrained designs.

High Reliability

Their passive mechanism ensures stable performance in overheating scenarios.

Standards and Requirements

National Standards

GB 4706.1-2005 mandates over-temperature protection for motors under abnormal conditions. Specific standards (e.g., GB 4706.27 for fans) may further require protection devices.

Mandatory Requirements

CCC certification requires over-temperature protection for motors, with thermal fuses or equivalent devices commonly used.

International Standards

IEC 60335 series and UL/CE certifications mandate over-temperature protection, with thermal fuses widely used.

Disposable thermal fuses prevent overheating risks in motors, with their reliability and compact design making them suitable. In China, GB 4706 standards and CCC certification indirectly mandate their use. Refer to GB 4706 standards or consult CCC certification bodies for specific requirements.

Why Use Disposable Current Fuses for Over-Current Protection in Power Supplies

Reasons

Prevent Safety Incidents from Over-Current

Power supplies in small appliances may experience excessive current due to short circuits, overloads, or external power issues, risking wire overheating, circuit damage, fires, or electric shock. Current fuses melt and disconnect the circuit when current exceeds rated values.

High Reliability and Fast Response

Operating on the physical principle of metal wire melting, current fuses ensure reliable and rapid activation, even in extreme conditions.

Non-Resettable for Safety

Their non-resettable design prevents restart until the issue is resolved, ensuring long-term safety.

Suitability for Power Supplies

Compact current fuses integrate easily into power input or critical circuits, fitting the compact designs of small appliances.

High Reliability

Their passive mechanism ensures stable performance in over-current scenarios.

Standards and Requirements

National Standards

GB 4706.1-2005 mandates over-current protection for appliances to prevent fires or electric shock. Specific standards (e.g., GB 4706.27) may further require protection devices.

Mandatory Requirements

CCC certification requires over-current protection for power supplies, with current fuses or equivalent devices commonly used.

International Standards

IEC 60335 series and UL/CE certifications mandate over-current protection, with current fuses widely used.

Disposable current fuses prevent over-current risks in power supplies, with their reliability and compact design making them suitable. In China, GB 4706 standards and CCC certification indirectly mandate their use. Refer to GB 4706 standards or consult CCC certification bodies for specific requirements.

Why Protect Lithium Batteries in Small Appliances Against Overcharge and Over-Discharge

Lithium batteries are used in appliances like vacuum cleaners, electric toothbrushes, portable fans, cordless irons, shavers, and handheld massagers. Their high energy density necessitates protection against overcharge and over-discharge due to the following reasons:

Prevent Overcharge-Related Safety Incidents

Overcharging can cause excessive voltage, leading to electrolyte decomposition, gas generation, battery swelling, or even explosion or fire. Protection circuits (e.g., Battery Management Systems, BMS) monitor voltage and current, cutting off charging when safe thresholds are reached.

Prevent Over-Discharge Damage

Over-discharging can lower battery voltage below safe levels, causing irreversible chemical damage, reducing battery life, or risking short circuits or leakage. Protection circuits disconnect discharge when voltage drops too low.

High Reliability and Safety

Lithium batteries are sensitive to voltage and current changes, risking thermal runaway. Protection mechanisms (e.g., BMS or fuses) provide reliable active or passive protection.

Suitability for Small Appliances

Compact BMS chips integrate easily into battery packs or appliances, meeting portability requirements.

Extend Battery Life

Protection against overcharge and over-discharge extends battery lifespan, reducing replacement costs and enhancing user experience.

Standards and Requirements

National Standards

GB 4706.1-2005

Requires safety protection for appliances under abnormal conditions (e.g., charger or battery faults). 

GB/T 35590-2017

Mandates overcharge, over-discharge, over-current, and short-circuit protection for lithium batteries. 

GB 31241-2022

Requires battery packs to include protection circuits (e.g., BMS) to prevent abnormal conditions.

Mandatory Requirements

CCC certification, based on GB 4706 and GB 31241 standards, mandates overcharge, over-discharge, over-current, and short-circuit protection for lithium batteries, typically achieved through BMS or fuses.

International Standards

IEC 62133-2 and IEC 60335 series require similar protections, with UL/CE certifications enforcing these standards.

Lithium battery protection in small appliances prevents safety risks and extends battery life. In China, GB 31241-2022 and GB 4706 standards, enforced by CCC certification, mandate these protections. Refer to these standards or consult CCC certification bodies for specific requirements.

SETsafe | SETfuse Solutions, Products

Over-Temperature Protection for Heating Resistors

Protection Type: Over-Temperature Protection 

Product:

Thermal-Link (ATCO) - Alloy Type 

Series: 

Radial, Lead: K  Learn more

Radial, Lead: Y  Learn more

Radial, Lead: X  Learn more

Radial, Lead: F  Learn more

Axial, Lead: H  Learn more

Axial, Lead: V  Learn more

Over-Temperature Protection for Heating Tubes

Protection Type: Over-Temperature Protection

Product:

Thermal-Link (ATCO) - Alloy Type

Series: Radial, Lead: SY  Learn more

Product:

Thermal-Link (OTCO) - Organic Type

Series: 

Axial, Lead: RS  Learn More

Axial, Lead: RT  Learn More

Over-Temperature Protection for Heating Coils

Protection Type: Over-Temperature Protection

Product:

Thermal-Link (ATCO) - Alloy Type

Series: Radial, Lead: Y  Learn more

Over-Temperature Protection for PI Heating Films

Protection Type: Over-Temperature Protection 

Product:

Thermal-Link (ATCO) - Alloy Type 

Series: 

Radial, Lead: K  Learn more

Radial, Lead: Y  Learn more

Axial, Lead: H  Learn more

Axial, Lead: C  Learn more

Over-Temperature Protection for PTC Heaters

Protection Type: Over-Temperature Protection 

Product:

Thermal-Link (ATCO) - Alloy Type 

Series: 

Radial, Lead: K  Learn more

Radial, Lead: Y  Learn more

Product:

Thermal-Link (OTCO) - Organic Type 

Series: 

Axial, Lead: RS  Learn More

Axial, Lead: RT  Learn More

Over-Temperature Protection for Motors

Protection Type: Over-Temperature Protection 

Product:

Thermal-Link (OTCO) - Organic Type 

Series: 

Radial, Lead: K  Learn more

Radial, Lead: Y  Learn more

Axial, Lead: H  Learn more

Axial, Lead: C  Learn more

Over-Current Protection for Power Supplies

Protection Type: Over-Current Protection

Product:

Miniature Fuses 

Series: 

Axial Tube, Lead: SCT520 & SCT520P  Learn more

Radial, Lead: SPT478  Learn more

SMD Type: SCT1032  Learn more

SMD Type: SCT6125  Learn more

Overcharge and Over-Discharge Protection for Lithium Batteries

Protection Type: Active Protection 

Product:

Thermal Cutoff (HCO) 

Series: 

SMD Type: SHL  Learn more

SMD Type: SHJ  Learn more

Partner with SETsafe | SETfuse to Transform Technical Challenges into Reliable Solutions

When you encounter technical challenges in selecting circuit protection components or designing system solutions, the professional engineering team at SETsafe | SETfuse is your trusted partner. Specializing in over-temperature, over-current, over-voltage, and active protection technologies, SETsafe | SETfuse offers comprehensive technical expertise and rapid response to meet your needs. Whether you require precise product parameter guidance or comprehensive system-level protection solutions, SETsafe | SETfuse delivers professional, practical, and efficient recommendations and support.

From initial design consultation and solution implementation to post-sales product assurance, we provide end-to-end collaboration, ensuring your project progresses seamlessly and reliably. For any inquiries or requirements, please contact us at: sales@SETfuse.com

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