Hong Kong Regulations

ELECTRICITY (WIRING) REGULATIONS - REGULATION 10

Neutral conductor protective devices, isolators and switches

(1) A single-pole switch shall be inserted in the phase conductor of a single
phase circuit only.

(2) No fuse and no circuit breaker, isolator or switch, other than a
linked circuit breaker, linked isolator or linked switch, shall be inserted in
a neutral conductor.

(3) Notwithstanding subregulations (1) and (2), a single-pole switch may be
inserted between the earthing connection and the neutral terminals of
generators running or likely to be running in parallel so long as adequate
precautions have been taken to avoid danger.

(4) A solid link may only be inserted in a neutral conductor so long as it
cannot be disconnected without first disconnecting the related
phase conductors.

(5) A linked circuit breaker, a linked isolator or a linked switch inserted in
a neutral conductor shall be arranged to break also the related
phase conductors. (Enacted 1990)