Specifications

NAIROBI OPERATIONAL HUB
UNOPS Building, UN Lane, Off UN Avenue Tel: [phone]
P.O Box 783,Village Market, 00621 E-mail: [e-mail]
Nairobi, Kenya Website: www.unops.org
UNOPS is ISO 9001 certified
B. In corridors DBs enclosure shall be housed in electrical closets. All
electrical closets shall be of the same size with architectural finishes as
required.
C. All risers falling in areas like corridors or important rooms shall be
provided with an hinged access door with finishes as required by architect.
D. The main isolating switch shall be of SPN or TPN air break design.
Where indicated on the Drawings, the MCBs for the lighting circuits and
socket outlet circuits shall be electrically separated by the provision of
separate busbars and each section shall be protected by a separate current
operated earth leakage circuit breaker. The RCCB shall afford earth
leakage protection for the lighting and power sections. Fuses shall be
provided for DBs wherever necessary and/or shown on drawings.
E. The neutral and earth terminal blocks should be provided with
arrangement for connecting on each block one cable for each outgoing
circuit and one incoming cable of size indicated on the Drawings. The
wiring between the RCCB and busbars shall be carried out with coloured
PVC insulated cables with copper conductors for phase identification. The
arrangement of the enclosure shall be such that the MCBs and COELCB
cannot be operated without opening the hinged door but to obtain access to
MCBs and COELCB, it should be necessary to remove a second cover.
Adequate clearance shall be maintained between phase and non-current
carrying metals. Terminals shall be so located that in the final connected
positions, there shall be no crowding of wires in close proximity of live
metals.
F. MCBs shall be so arranged in the board that it shall be possible to replace
a triple pole MCB with three adjacent single pole MCBs or vice versa. The
board shall be flush mounted type unless indicated otherwise on the
Drawings. Cable glands shall be provided where required.
G. MCB
MCB shall comply with EN60439-3 and shall be symmetrical rail
mounted type available in one, two, three or four poles version. They shall
be trip free type with quick make, quick break mechanism. The rated
ultimate breaking capacity (Icu) of the MCB’s shall be at least equal to the
prospective fault level at the point of the distribution system where they
are installed, unless cascaded with an upstream breaker. The minimum
rated ultimate breaking capacity (Icu) of the MCB shall be 10 kA if not