What is a ceramic tube fuse?

Comprehensive analysis of ceramic tube fuses
1、 Definition and Structure
Ceramic tube fuse is a fuse device with a ceramic tube as the outer shell, which contains metal fuse elements (such as copper, nickel alloy wire), lead terminals, and fillers (such as quartz sand or mineral powder) inside. Its core structure includes:
Ceramic tube shell: provides mechanical protection and electrical insulation, high temperature resistance, and corrosion resistance.
Fuse element: composed of metal wire or sheet, which melts when the current is overloaded.
Filler: Absorbs the arc energy generated during melting to enhance safety.
Lead terminal: Connect external circuits to ensure stable conductivity.
2、 Working principle
Based on the thermal effect, when the circuit current exceeds the rated value:
Heat accumulation: The fuse element generates heat due to resistance, causing the temperature to rise.
Material melting: After reaching the melting point, the metal fuse element melts and cuts off the circuit.
Arc suppression: Ceramic tubes and fillers quickly absorb arc energy to prevent explosions or sparks.
3、 Core Features
High temperature resistance and explosion-proof
Ceramic materials can withstand high temperatures (up to 400 ℃), with no risk of explosion when blown, and are suitable for high current or harsh environments.
High insulation
Ceramic casing provides reliable electrical insulation and reduces the risk of short circuits.
Strong breaking ability
Can safely disconnect high currents (such as short-circuit currents) and protect equipment from damage.
Diversified types
Fast break type: With a fast response speed, it is used for short-circuit protection (such as power circuits).
Slow break type: with a longer melting time, suitable for overload protection of capacitive loads such as motors.
Time delayed type: Provides brief overcurrent protection (such as motor start-up).
4、 Application scenarios
High current/high voltage equipment
Power system: Overload and short-circuit protection for transformers, generators, and switchgear.
Industrial equipment: motors, welding machines, frequency converters, and other scenarios that require high breaking capacity.
Explosion proof requirements for places
Aerospace: resistant to vibration and high temperature, ensuring the safety of electronic devices.
Petrochemical/Mining: Prevent accidents caused by electric arcs in flammable and explosive environments.
Automotive Electronics
Engine, headlights, and air conditioning circuit protection, suitable for high temperature and vibration environments.
Household Electric Appliances
TV sets, refrigerators, air conditioners, etc., especially those that require high temperature resistance and moisture resistance.
5、 Compared with other types of fuses
Characteristics: Ceramic tube fuse, glass tube fuse, plastic shell fuse
Shell material: Ceramic (high temperature resistant, explosion-proof), Glass (transparent but fragile), Plastic (low cost but poor temperature resistance)
Suitable for high current (such as 10A-30A), low current (usually ≤ 10A), and low current (usually ≤ 5A)
Excellent explosion-proof performance (no explosion risk), poor (may rupture), moderate (may burn)
Application scenarios: Industrial, automotive, aerospace household appliances, low-voltage control boards, consumer electronics, low-voltage circuits
6、 Selection Guide
Rated current
Choose a model slightly higher than the normal operating current of the circuit to ensure reliable melting in case of overload.
Example: The working current of the circuit is 5A, and a 6A ceramic tube fuse can be selected.
Voltage level
The withstand voltage should be higher than the working voltage of the circuit (such as using a 250VAC fuse for a 220V circuit).
Environmental adaptability
High temperature environment: Choose models that can withstand temperatures above 400 ℃.
Wet/Corrosive Environment: Choose ceramic tube fuses that are moisture-proof and dust-proof.
Fusing characteristics
Quick break type: Short circuit protection (such as power circuit).
Slow break type: Overload protection for capacitive loads such as motors and transformers.
7、 Summary
Ceramic tube fuses have become the preferred choice for circuit protection in high current, high voltage, and harsh environments due to their high temperature resistance, explosion resistance, high insulation, and strong breaking ability. Users need to choose the appropriate model based on specific scenarios (such as industrial equipment, automotive electronics) and circuit parameters (current, voltage) to ensure safe and stable operation of the equipment.