Types of Fuses:

Two types of Fuse:

Low voltage Fuse:

Low voltage fuses can be subdivided into two viz.,

(!) Semi-enclosed rewire able fuse: The use of this type of fuses is limited to domestic and lighting loads.

(!!) High-rupturing capacity (H.R.C) cartridge fuse: They are extensively used on low-voltage distribution of system against over-load and short-circuit conditions.

High Voltage Fuse: High voltage fuses can be subdivided into three.

(!) Cartridge type: Used up to 33KV

(!!) Liquid type: Used up to 133KV

(!!!) Metal clad fuses: Can be used for very high voltage circuit.

Screws, bolts and springs

Check tightening screws and bolts of each part for loosening. Tighten them if loose. Check each spring for proper engagement and damage. Correct problem by repair or replacement.

Dirt and dust

Latching parts should be free of dirt and dust. Wipe them with a clean cloth

Coil

Measure the coil resistance with an ohmmeter .if it is much lower than the value 1 or there is no continuity, replace the SHT

Terminal and mounting screws

Check terminals and mounting screws for loosening. Tighten them if loose.