No_5_February_1964 — Page 107

There are 12 rising main ducts, with one or two ducts in each wing, provided throughout the building to accommodate the electrical services. In cach of the typical rising main ducts a totally enclosed 300 amp. T.P. & N. rising main busbar has been provided for non-essential supply and 4-core plastic main cables, P.V.C. insulated and sheathed. and steel wire armoured together with rising main junction boxes have been pro- vided for essential supply. Each final sub-circuit of either essential or non-essential circuit. to each of the thirteen floor distribution boards in the high rise wings is taken

taken from respective rising mains. Final sub-circuit protec- tion utilises some 4000 miniature circuit breakers housed in locally manufactured distribution boards of various sizes. The supply cables for the lifts and fire booster pumps are also in plastic main cables running from the submain switchboard in the basement directly to the motor room on the roof.

In addition, the rising cables for telephone system, impulse clock sys- tem, fire alarm system and radio distribution system are all accom. odated in the same duct.

In the sub-circuit wiring P.V.C. insulated cable is employed and en- closed in heavy gauge galvanized conduits which have been buried in

concrete during the progress of building work. The medium and low voltage cables are segregated from the extra low voltage cables by run- ning in separate conduit or in diffe rent compartments of the trunking. In view of the structural limitation, the conduits were only installed on the surface of concrete walls and columns and covered by Celocrete and plaster for the installa- tion of Aush electrical accessories. The conduit runs were carefully plan- ned and installed to include space for all electrical services such as radio, telephone, fire alarm sys- tems etc. Surface mounted conduits

and trunkings were installed in the basement airconditioning plant rooms, laundry and boiler room.

All the external lights including road lights, floodlights and lights. along the public accessed corridors and paths have centralised control

▲ Enquiry counter at main entrance hall.

THE HONG KONG & FAR EAST BUILDER - VOLUME 18. NUMBER 5

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Detail of canopy over wall facing garden forecourt.

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