4 Types of Fuses

The fuse is a practical part of an electrical device because it helps to protect the circuit and avoid issues with overloads. There are plenty of different fuses in the market, but most include a non combustible material to house a low-resistance metallic wire. In the event of a mismatched load, over current or short-circuit, the thin wire is designed to instantly melt in view of the much higher current flow and heat generation.

Here are a few of the most popular types of fuses:

Current limiting

The current-limiting fuse is a type of high interrupting fuse that is designed to safety break at 600 AC V and up to 300,000 amperes. A great benefit of this fuse is the speed that it is capable to operate which helps to protect the electrical devices from potential damage.

Resettable

The resettable fuse has a built-in polymeric positive temperature coefficient (PPTC) thermistor to protect a circuit in the event of an over current situation. This type of self-resetting fuses is reusable and will revert back to low resistance once its device has cooled. This fuse is a popular choice for nuclear or aerospace applications where it would be very difficult to install a replacement. Also, they feature in a PC motherboard to protect it against permanent damage in the event of a short keyboard or mouse.

Thermal

The thermal fuse is a popular choice for a wide range of consumer electronics such as hair dryers and coffee machines. This fuse has a spring contact mechanism held close by a fusible, temperature-sensitive alloy. In the event of a sudden increase in temperature, the alloy will quickly melt and break contact with the circuit. This is useful in a hair dryer when the heating element is blocked to avoid the risk of fire. The thermal fuse is one time use and must be replaced in the event of being blown.

High-voltage

The high-voltage fuse is the right choice for a powered system that runs up to 115,000 AC volts. It is used in small power transformers or for electricity metering. For instance, it can feature in a distribution system to give appropriate protection to a transformer that is serving multiple properties. This is a large and expensive fuse that can be rebuilt in the event that it is blown. They are built using predictable and stable elements, such as tin, copper and silver. Also, certain fuses contain gas-evolving substances, which are only practical for outdoor use.