The load current flows through the thermal and the
Fuse element
Glass ceramic body
End-cap
FIGURE 12.
● The cartridge may shorted out wire silver foil extreme
cases bad practice.
● not possible see the fuse element broken. 12.2
Cartridge fuse.
● The declared rating accurate.
● Their operation more rapid than semi-enclosed fuses. Operating
time inversely proportional the fault current, the bigger the
fault current the quicker the fuse operates. MCB overcomes this problem since automatic switch
which opens the event excessive current flowing the circuit and
can closed when the circuit returns normal. They may also filled with
quartz sand absorb and extinguish the energy the arc when the car-
tridge brought into operation. Cartridge fuse construction illustrated Fig.
An MCB the type shown Fig. 12.
ADVANTAGES CARTRIDGE FUSES
● They have mechanical moving parts.
Miniature circuit breakers (BS 60898)
The disadvantage all fuses that when they have operated they must be
replaced.2.
DISADVANTAGES CARTRIDGE FUSES
● They are more expensive replace than fuse elements that can be
re-wired.
.
● They can replaced with incorrect cartridge.Basic Electrical Installation Work
242
to the body the fuse that they not blow off when the fuse oper-
ates.
● The element does not weaken with age.
● They are easy replace. With larger size
cartridge fuses, lugs tags are sometimes brazed the end-caps fix
the fuse cartridge mechanically the carrier.3 incorporates thermal and mag-
netic tripping device.
● They have small physical size and external arcing which permits
their use plug tops and small fuse carriers
