● faulty circuit may quickly identified.
● They contain mechanical moving parts and therefore require regular
testing ensure satisfactory operation under fault conditions.
● Tripping characteristics and therefore circuit protection set the
installer.
● faulty circuit may easily and quickly restored.
DISADVANTAGES MCBs
● They are relatively expensive but look the advantages see why
they are popular these days.
The circuit can restored when the fault removed pressing the ON
toggle.
● The supply may safely restored unskilled operator.
● The circuit provided with discrimination. This latches the various mechanisms within the MCB and ‘makes’
the switch contact.
● The circuit protection difficult interfere with.3
MCBs Breaker, fits Wylex Standard consumer unit (Courtesy Wylex).
CHARACTERISTICS MCBs
MCB Type 60898 will trip instantly between three and five
times its rated current and also suitable for domestic and commercial
installations.
ADVANTAGES MCBs
● They have factory set operating characteristics.
FIGURE 12.
. The toggle switch can also used disconnect the
circuit for maintenance isolation test the MCB for satisfactory
operation.Overcurrent, short circuit and earth fault protection
243
electromagnetic devices normal operation but under overcurrent condi-
tions they activate and trip the MCB
