HRC Fuses And How They Function


HRC fuse is one of the fuses wherein the wire transfers a short circuit current for a certain period. If a fault occurs in the circuit, it explodes apart. The current flowing through the electrical network is within the rated limit while it is operating properly.

When a defect occurs in the network, the network current exceeds the rated limits, primarily due to a phase to phase short circuit fault or a phase to ground fault. This high current may have a significant thermal effect, causing lasting damage to the important equipment connected to the electrical network. As a result, this high fault current should be cut off as soon as feasible. An electrical fuse enables this.

HRC is an abbreviation for High Rupturing Capacity. HRC Fuse has an extremely high rupturing capacity which is why they are so popular. Because of its high current rupturing capacity, HRC Fuse requires a unique way of arc extinguishment in its construction.

Characteristics of A HRC Fuse

A fuse operates when its element melts due to the heat created by I2RF, where RF is the resistance of the fuse. As the current flowing through the Fuse element grows, so does the amount of heat produced. As a result, we can deduce that a fuse element melts faster when the fault current is high, while it takes longer when the fault current is low. This time-current relationship of a fuse is known as its characteristics, and it is particularly useful for optimal fuse selection for a certain circuit and for coordination purposes.

The chemical reaction between the filling power and the silver vapour will produce a high resistance product that will help in reducing the arc inside the fuse. Because of their low resistance, copper or silver are commonly employed. A fuse element typically consists of two or more parts joined together by a tin.

The melting point of tin is 2400° C, which is lower than the melting point of silver, which is 980° C. Which is why the melting point of tin joints prevents the fuse from reaching high temperatures in the event of a short circuit or overload.

How a HRC Fuse Functions

Under typical circumstances, the current does not provide enough heat to melt it. If more current flows than the fuse’s limit, the fault current melts the element before it reaches its peak. When the fuse is overloaded, the fuse ingredient does not melt; nevertheless, if such a condition persists for an extended period of time, a substance such as eutectic will melt and break the fuse element.

When the fuse is short-circuited, the thinner components of the fuse element melt faster in a smaller region. It will also fail before the eutectic substance. As a result, HRC has to include limits within the fuse element.