Basic Electrical Installation Work

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