Composite fuse cutout is a electrical protection device for overhead line systems to prevent distribution transformers from being damaged by power surges. Fuse cutout insulators has a fuse link in series with the transformer feed cables. The link passes through a hinged tubular fuse holder in such a way that it secures the fuse holder in position on the cutout body. When the current exceeds a specified value for a period of time and fusing will melt by the heat generated by itself and separate under overcurrent conditions, the fuse holder will drop free under its own weight, pivot down on the hinge and hang vertically, giving a clear visual indication of its status. Most fuse cutout designs also incorporate a metal ring on the fuse holder, which allows maintenance and repair personnel to manually disconnect the fuse should they be required to work on the transformer. Cutout was widely used in high and low voltage power distribution systems and control systems, as well as electrical equipment, as short-circuit and over-current protectors, and are one of the most commonly used protection devices.

Component of fuse cutout:

  1.  Composite insulator
  2.  Top hood
  3.  Backup spring
  4.  Silver plated copper contact
  5.  Galvanized steel hook
  6.  Silver plated fuse  tube head
  7.  Pull ring
  8.  Fuse tube
  9.  Bottom tube casting
  10.Link ejector
  11.Alloy hinge  

Type Rated Voltage
(kV)
Rated Current
(A)
Breaking Current
(A)
BIL
(kV)
Power frequency Withstand Voltage
(kV)
Leakage Distance
(mm)
OFC-12 12 100 10000 45 110 245
200 12000
OFC-24 24 100 10000 65 110 540
200 12000
OFC-36 36 100 10000 70 170 720
200 12000