
Fuses are devices that provide overcurrent protection to electrical circuits. While both fuses and circuit breakers protect electrical circuits, they operate differently. Fuses such as cartridge fuses are single-use devices that must be replaced once they blow, whereas circuit breakers can be reset and reused multiple times. Circuit breakers such as an [RCBO](https://au.rs-online.com/web/content/discovery/ideas-and-advice/rcbo-guide) are more convenient and often used in residential and commercial buildings, but fuses remain popular in certain applications due to their simplicity and reliability.

Among [fuses](https://au.rs-online.com/web/c/fuses-circuit-breakers/fuses/), cartridge fuses are low-cost electrical safety devices used to protect the overload of electrical circuits and appliances. They are cylindrical and have a contact point at each end. Cartridge fuses are typically constructed from ceramic, glass, or porcelain.

Moreover, cartridge fuses come in various sizes to accommodate different electrical loads and applications. The fuse size determines its current rating and voltage capacity, ensuring it can effectively protect the specific circuit it is designed for.

## **How Do Cartridge Fuses Work?**

Cartridge fuses contain a piece of wire that melts when too much current flows through the circuit. When the wire melts, it breaks the circuit, preventing damage to the connected devices and [contactors](https://au.rs-online.com/web/c/automation-control-gear/contactors-auxiliary-contacts/contactors/). This is often referred to as burning out or blowing out. Put simply, when a fuse blows, the circuit is broken. Once a fuse has blown, it will need a replacement to complete the circuit and allow the current to flow. Ensuring proper fuse ratings and [optimising electrical wiring](https://au.rs-online.com/web/content/discovery/ideas-and-advice/optimising-electrical-wiring-with-heat-shrink-tubing) with [heat shrink tubing](https://au.rs-online.com/web/c/cables-wires/cable-joints-cable-sleeving/heat-shrink-tubing/) can significantly enhance the safety and efficiency of your electrical systems.

## **Why Use Cartridge Fuses?**

Cartridge fuses are a relatively cheap way of protecting electrical equipment from short circuits and overcurrents. They are incredibly safe as they do not produce flames, arcs, or gas when they burn out and break the circuit.

## **Types of Fuse Markings and Speed Codes**

Cylindrical cartridge fuses are used in a range of industrial, commercial, and domestic applications. Selecting the correct fuse speed is essential for the protection of your device. Here are some of the most common markings you will find on a cartridge fuse.

- FF = Very Fast Acting (Flink Flink)
- F = Fast Acting (Flink)
- M = Medium Acting (Mitteltrage)
- T = Slow Acting (Trage)
- TT = Very Slow Acting (Trage Trage)

## **What Current Rating Should You Choose?**

Cartridge fuses are available in a range of standard amperages. When choosing the correct fuse for your application, you should select a fuse with a nominally higher current rating than the device that it is being used in. This means that if there is a slight, harmless power increase, the fuse will not blow.

Cartridge fuses come in various current ratings, typically ranging from fractions of an ampere to several hundred amperes. Here’s a breakdown of common cartridge fuse ratings:

- **20 Amp Cartridge Fuse:** Ideal for protecting household appliances, small motors, and lighting circuits.
- **30 Amp Cartridge Fuse:** Commonly used in larger household appliances and small industrial equipment.
- **40 Amp Cartridge Fuse:** Suitable for moderate industrial applications and larger residential systems.
- **50 Amp Cartridge Fuse:** Often used in heavy-duty industrial equipment, large HVAC systems, and significant residential power needs.
- **60 Amp Cartridge Fuse:** Typically found in industrial machinery, large electrical panels, and commercial HVAC systems.
- **80 Amp Cartridge Fuse:** Used for very high-power applications, such as industrial plants, large machinery, and main electrical service panels.

In addition to the current rating, consider the breaking capacity of the cartridge fuse. Breaking capacity is the maximum current a fuse can safely interrupt without exploding or rupturing. The breaking capacity should always exceed the fault current of your circuit to ensure safety.

## **Industrial Applications of Cartridge Fuses**

Cartridge fuses are used in different types of industrial settings for protecting heavy machinery and electrical equipment from overcurrent conditions.

For example, in manufacturing plants, cartridge fuses safeguard motors, transformers, and control circuits, preventing costly downtime and equipment damage. 

Additionally, cartridge fuses are used in [HVAC systems](https://au.rs-online.com/web/c/hvac-fans-thermal-management/) to protect compressors and fans, and in industrial automation to secure programmable logic controllers (PLCs) and other control devices.

## **Buying Cartridge Fuses: Ordering and Delivery Information for Australia**

RS is a trusted supplier and distributor of cartridge fuses, offering a comprehensive range from industry-leading brands such as [Eaton](https://au.rs-online.com/web/c/fuses-circuit-breakers/fuses/cartridge-fuses/?applied-dimensions=4294966708), [Littelfuse](https://au.rs-online.com/web/c/fuses-circuit-breakers/fuses/cartridge-fuses/?applied-dimensions=4294966152), [Mersen](https://au.rs-online.com/web/c/fuses-circuit-breakers/fuses/cartridge-fuses/?applied-dimensions=4294966048), and [RS PRO](https://au.rs-online.com/web/c/fuses-circuit-breakers/fuses/cartridge-fuses/?applied-dimensions=4291780588). 

We also ensure reliable delivery, offering next working day service if ordered before 5 pm AEST Monday to Friday or a specific day within the next 12 months. 

For detailed information regarding ordering and [delivery](https://au.rs-online.com/web/content/support/all-articles/delivery), please call our customer service.



Cartridge Fuses

Fuses

Fuses & Circuit Breakers

Electrical, Automation & Cables

Automation & Control Gear

Automation Signalling

Contactors & Auxiliary Contacts

Electric Motors

Industrial Robots

PLCs, HMIs & Industrial Computing

Process Control

Sensors

Solenoids

Cables & Wires

AV Cables

Cable Glands & Fittings

Cable Joints & Cable Sleeving

Cable Management

Cable Ties & Fixings

Computer Cables

Electrical Power & Industrial Cables

Networking & Coaxial Cables

Single Core Cable

Wire to Board Cables & Ribbon Cable

Enclosures & Server Racks

19-Inch Racking

Enclosures

Enclosures & Racking Components

Circuit Breakers

Earth & Lightning Protection

Fuse Holders & Accessories

HVAC, Fans & Thermal Management

Air Conditioning & Fans

Air Conditioning & Heating Accessories

Building Automation

Electronics Heating & Cooling Components

Fan Accessories

Heaters & Radiators

Lighting

Fluorescent Lamps & Tubes

Light Bulbs, Lamps & Tubes

Light Fittings, Fixtures & Luminaires

Lighting Components

Torches & Inspection Lamps

Relays & Signal Conditioning

Relay Accessories

Relays

Signal Conditioners & Isolators

Switches

Capacitive, Magnetic and Piezo Switches

DIP & Rotary Encoded Switches

Domestic Installation Switches

Foot Switches & Components

Joysticks & Components

Key Switches & Selector Switches

Keyboard & Keypad Switches

Limit & Position Switches

Micro Switches & Detector Switches

Push Button Switches & Components

Rocker Switches & Components

Rope Pull Switches & Components

Rotary Switches & Components

Safety Enabling & Control Switches

Safety Interlock Switches & Components

Switch Disconnectors & Components

Toggle Switches & Slide Switches

Electronic Components, Power & Connectors

Batteries & Chargers

Battery & Charger Accessories

Battery Chargers & Power Banks

Non-Rechargeable Batteries

Rechargeable Batteries

Connectors

AV Connectors

Automotive Electrical Connectors

Backplane & Rack Connectors

Circular Connectors

IC Sockets & Adapters

Mains & DC Power Connectors

Network & Telecom Connectors

PCB Connectors & Wire Housings

Power Connectors

RF Coaxial Connectors & Adapters

Terminal Blocks

USB, D Sub & Computing Connectors

Wire Terminals & Splices

Displays & Optoelectronics

Display Modules

Fibre Optic Components

Indicators & Indicator Components

LED Lighting Components

LEDs - Light Emitting Diodes

Laser Modules & Components

Optocouplers & Photodetectors

ESD Control, Cleanroom & PCB Prototyping

ESD Control & Clean Room

PCB Etching, Preparation & Developing

PCB Handling

PCB Spacers, Pillars & Supports

PCB Tools

Prototyping Boards

Passive Components

Antennas

Capacitors

Crystals, Oscillators & Resonators

EMI Filters & Protection

Fixed Resistors

Inductors

Passive Components Kits

Rotary Encoders

Sounder, Buzzer & Microphone Components

Surge Protection Components

Variable Resistors

Power Supplies & Transformers

Power Supplies

Renewable Energy

Transformers

Voltage Converters

Raspberry Pi, Arduino, ROCK, STEM Education & Development Tools

Arduino Shop

BBC micro:bit Shop

Development Tools & Single Board Computers

ROCK SBC Shop

Raspberry Pi Shop

STEM Education

Semiconductors

Amplifiers & Comparators

Audio & Video ICs

Chip Programmers & Debuggers

Clock, Timing & Frequency ICs

Communication & Wireless Module ICs

Data Converters

Discrete Semiconductors

Interface ICs

Logic ICs

Memory Chips

Power Management ICs

Processors & Microcontrollers

Programmable Logic ICs

Sensor ICs

Mechanical, Fluid Power & Tools

Access, Storage & Material Handling

Ladders & Steps

Material Lifting & Loading Equipment

Storage & Shelving

Transit & Equipment Cases

Trucks, Trolleys & Lifting Tables

Adhesives, Sealants & Tapes

Adhesive, Sealant & Tape Dispensers

Adhesives & Glues

Sealants & Resins

Tapes

Bearings & Seals

Gaskets, Seals & Packings

Linear Motion

Rotary Bearings & Housing Units

Engineering Materials & Industrial Hardware

Anti Vibration & Levelling Components

Carbon Fibre & Felt Sheets

Castors & Wheels

Ceramic Materials

Channel Support Systems

Conveyor Components

Insulation Materials

Knobs, Levers & Handles

Metal Materials

Plastic & Rubber Materials

Polishing & Finishing

Shim Stock

Structural Systems

Fasteners & Fixings

Clips & Springs

Girder Fixings

Magnets & Magnetic Strips

Nails & Rivets

Nuts & Washers

Pins, Keys & Retaining Clips

Screws & Bolts

Sheet Metal & Panel Fasteners

Spacers & Standoffs

Wall Plugs, Fixings & Anchors

Hand Tools

Cable, Connector & Crimping Tools

Clamps & Vices

Hammers & Demolition

Knives, Scissors & Saws

Manual Grease Guns & Accessories

Measuring & Marking

Pliers & Cutters

Sanding, Filing & Polishing

Screwdrivers, Hex & Torx Keys

Spanners, Sockets & Wrenches

Specialist Tools

Staplers & Riveters

Threading Tools

Tool Kits & Tool Storage

Mechanical Power Transmission

Belts & Pulleys

Brakes & Clutches

Bushes & Collars

3a Fuses

0 Products showing for 3a Fuses

Popular Searches

Related links