All Types of Fuse Symbols and Diagrams

Hey, in this article, we are going to see all types of fuse symbols and diagrams. You must know and remember the symbol of fuse forever. There are so many electrical protective and safety devices. Fuse is one of them. A fuse is a current-interrupting device. When an excessive current flows in a circuit, the fuse will break the circuit. Fuses are more suitable to protect the devices or circuits from overload faults than short circuit faults. In earlier days, the fuse was the only one best protective device and was used in most of the electrical and electronic circuits.

There are different types of fuse categorized by current rating, voltage rating, breaking capacity, response time, current vs time characteristics, etc. The symbol of fuse is also categorized by the different standards such as IEC System, IEE/ANSI System, etc.

Some important types of fuse are,

• Normal Fuse
• Thermal Fuse
• Fuse with Switch
• Fast Blow Fuse
• Slow Blow Fuse
• Fuse with Striker
• Oil Fuse
• Fuse with alarm Contact
• Fuse with Isolator

Read Also: All Types of Relay Symbol and Diagram

Basic Fuse Symbol - IEC and ANSI System

Here, you can see the basic symbol of fuse used everywhere means all the circuit diagrams, wiring diagrams, electrical drawings, etc. These are the same for cartridge fuse, HRC Fuse, and Glass Fuse. So, it will help you to understand any electrical drawings to identify the protective device.

Symbol of Thermal Fuse

Thermal fuse works on the principle of thermal or temperature sensing. It breaks the circuit when the temperature of the fuse element reaches or crosses the threshold temperature. There is no current threshold for breaking the circuit. Although, the excessive flow of current causes to raises the temperature above the threshold. And it breaks the circuit.

Symbol of Fuse with Switch

The fuse with switch or fused switch is mostly used in electrical or electronic devices. It performs both functions - switching and protecting. We can manually turn on or off the device using this fused switch. When a fault occurs, it will automatically turn off the device by breaking the circuit. Here, also we need a new fuse after the old one is burned. This type of fuse switch is used in electronic devices.

Fast Blow Fuse Symbol

Fast Blow Fuse is categorized by response time and breaking capacity. It breaks the circuit instantly when the flow of current exceeds the threshold limit. Fast blow fuses are used in highly sensitive circuits, devices, etc where instant interruption is required. Fast blow fuses are made of thin fuse elements.

Read Also: Rheostat Symbol, Diagram, and Connection

Slow Blow Fuse Symbol

Slow Blow Fuse is also categorized by response time. It does not affect more by breaking capacity. The main function of a slow blow fuse is, it can withstand high current flow for a short time duration without being blown. Slow blow fuses are generally used in motor power circuits. The motor draws a very high current in starting, so the slow blow fuse can withstand this current during the starting of the motor. Basically, they are designed to detect and give protection against long-term high current faults.

Symbol of Fuse with Striker

It is a fuse with indication. We can see from the outside whether the fuse is blown or not. Generally, it has a pin-type element connected to an internal element and is visible from the outside. So, when the fuse is blown, the striker pin will pull out. So, we can confirm that the fuse is blown. This type of fuses are used in large stations, plants, control rooms, large machineries, etc.

Oil Fuse Symbol

Oil fuses are designed in such a way that the fuse element is immersed in oil. Oil is used as a coolant. The fuse element is immersed in oil to increase the breaking capacity and response time. The Oil type fuses are mostly used in medium to high voltage switchgear protection systems. Of course, insulating oil is used as coolant.

Read Also: All Types of Capacitor Symbol and Diagram

Symbol of Fuse with Alarm Contact

It also works like the fuse with the striker. It has an inbuilt circuit for alarm circuits. When the fuse is blown, the alarm circuit will be triggered, so we can know the fuse is blown or not. Here, the fuse is connected to the main power circuit is to be protected and alarm contact is connected to the alarm circuit and an auxiliary power supply. It may be connected through relay also.

Symbol of Fuse with Isolator

It is inbuilt with an isolator system. After blowing the fuse the isolator confirms the permanent and confirmed breaking of the circuit. In normal condition, we can connect and disconnect the isolator. So do not need to remove the fuse. This helps for compact installation and devices.

Read Also: All Types of Diode Symbol and Diagrams

Thank you for visiting the website. keep visiting for more updates.