Basic Electrical Installation Work

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● The supply may safely restored unskilled operator. ● faulty circuit may quickly identified. ● The circuit provided with discrimination. DISADVANTAGES MCBs ● They are relatively expensive but look the advantages see why they are popular these days. . ● faulty circuit may easily and quickly restored. The circuit can restored when the fault removed pressing the ON toggle. ● They contain mechanical moving parts and therefore require regular testing ensure satisfactory operation under fault conditions. This latches the various mechanisms within the MCB and ‘makes’ the switch contact. FIGURE 12.3 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. ● The circuit protection difficult interfere with. The toggle switch can also used disconnect the circuit for maintenance isolation test the MCB for satisfactory operation. ● Tripping characteristics and therefore circuit protection set the installer.Overcurrent, short circuit and earth fault protection 243 electromagnetic devices normal operation but under overcurrent condi- tions they activate and trip the MCB. ADVANTAGES MCBs ● They have factory set operating characteristics