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
upto 80A 100/125A frame size
100A to 160A 250A frame size.
250A to 350A 400A frame size.
350A and above 630A frame size
N. Each MCCB’s shall have minimum 2 pairs of NO /NC auxiliary contacts
2.09 EARTH LEAKAGE RELAYS
A. Earth Fault Relay
a. The relays shall comply with IEC 755
b. The relays shall be protected against nuisance tripping caused by
switching surges or by lighting surges.
c. The relays shall be of solid state type (mechanical type shall not be
accepted),self protected from high magnitude earthfaults and
protected against dirt, vibration and moisture.
d. The relays shall be able to operate in the presence of fault currents
with DC components.
e. Each relay shall accept a wide range of auxiliary supply voltages
from 48V to 240V AC and 48V to 300V DC as per the
requirement in the drawings.
f. The sensitivity of relays shall be adjustable as per the requirement
in the drawings from 0.03A to onward. The relays shall have time
delay option if required from instantaneous to 1 sec. using an 8
position switch.
g. The size of the relays shall be compact. They shall be suitable for
mounting on symmetrical rail horizontally or vertically.
h. The relays shall be equipped with one changeover output contact.
The continuity of the measurement circuit shall be monitored to
ensure that the toroid circuit is not open.
B. Current Sensors (Toroids)
a. Rectangular type for busduct feeders
b. Circular type for cable feeders
c. The range of associated toroidal transformer shall be of the closed
type with an inside diameter of 30 to 200 mm.
d. To have cable guides to ensure that feeder cable is centered within
the sensor.