Hong Kong Regulations

ELECTRICITY (WIRING) REGULATIONS - REGULATION 6

Circuit arrangement

(1) A wiring installation shall be divided into as many circuits as are
necessary in order to-

   (a)  avoid danger in the event of a fault; and

   (b)  facilitate safe operation, inspection, testing and maintenance.

(2) A separate circuit shall be provided for each part of a wiring
installation that needs to be separately controlled.

(3) Where a wiring installation comprises more than one final  circuit-

   (a)  each final circuit shall be separately protected against overcurrent
        and connected to a separate isolation device in a distribution  board;

   (b)  the wiring of each final circuit shall be electrically separated from
        that of every other final circuit, so as to prevent indirect
        energisation of the final circuit intended to be isolated; and

   (c)  each final circuit shall be designed so that it is not affected by the
        failure of any other final circuit. (Enacted 1990)