In: Electrical Engineering
Generally, a single-phase power is commonly found in domestic households, whereas a three-phase power is preferable for larger demands. For safety purpose, over-current protection components are compulsory in the electrical distribution systems.
i. Explain two advantages of a three-phase system compared to a
single-phase system in the distribution system.
ii. Briefly describe the characteristic and the function of two
types over-current protection device installed in the distribution
board (DB) residential building.
iii. Miniature circuit breakers (MCB) with different current rating
can be used to protect the individual sub-circuit. State the
current rating of the MCB that typically used for:
• lighting,
• socket outlet (radial type),
• socket outlet (ring type) and
• air-conditioner circuits.