HRC Fuse (High Rupturing Capacity Fuse)

This type of fuse contains a fuse wire, which carries the short-circuit current safely for a given time period. During this period, if the fault is removed, then it does not blow off; otherwise, it will melt and remove the circuit from the electrical supply, hence the circuit remains safe.
 

The common material, which is used to make an HRC fuse, is glass, but this is not always the case. Other chemical compounds are also used in HRC fuse manufacturing and construction based on different factors. Its external enclosure is made fully airtight in order to avoid the effect of the atmosphere on the fuse materials. The major objection on HRC fuse is the low and uncertain breaking capacity of the semi-enclosed fuse.
 

Construction and Operations of HRC fuse:

HRC Fuse consists of a highly heat-resistant material (such as ceramic) body having metal-end caps, which is welded by a silver current-carrying element. The fuse body's internal space is completely packed with a filling powder. The material, which has filled the insider space, may be plaster of Paris, quartz, chalk, marble, dust, and cooling mediums, etc. That's why it carries normal current without overheating.

The heat being produced vaporizes the silver element. A chemical reaction taking place between silver vapor and filling powder results in high resistance substance, which helps in quenching the arc in the fuse.

Advantages of HRC Fuse:

It clears high as well as low fault currents.

Do not deteriorate with age.

Having high-speed operation.

Provides reliable discrimination.

Require no maintenance.

Cheaper than other circuit interrupting devices with the same rating.

Permit consistent performance

Fusing operation is fast without Noise and Smoke
 

Disadvantages of H.R.C Fuse:

After each operation, they have to be replaced.

Heat being produced by the arc may affect the associated switches.