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
D. Starters shall have in addition to the auxiliary contacts required for
interlocks, alarms, BAS, and controls two additional sets of normally open
and normally closed contacts.
E. Motor Protection against the short-circuit shall be achieved by motor
circuit breakers of moulded case type and the combination with control-
command devices (Breaker + Contactor + Overload relay) shall be of type
2 co-ordination as defined by the IEC standards 947-4.1. The type 2 co-
ordination should be tested in laboratory and the manufacturer should
guarantee the same by submitting the type-2 co-ordination tables. The co-
ordination table shall indicate for each motor rating, the circuit breaker
type and set up characteristics, the contactor type and the thermal relay
type with its setting range.
The specifications mentioned in the MCCB’s section is applicable for the
breakers used in the motor protection. The moulded case circuit breakers
used for motor protection shall be equipped with adjustable magnetic trip
unit for short-circuit protection with settings from 6 to 14 times the
nominal rating of the device.
The contactors used for Motor protection shall have contactor utilization
category AC3 at 415V 50Hz as per IEC 947-4. Tripping class for
overload relays used for motor protection shall be of one of the tripping
class (class 10A, 10, 20, 30) as per IEC 947-4 depending on the motor
starting characteristics.
F. For each starter, provide the following :
1. 1 set of ‘ON’ and ‘OFF’ push buttons for starting and stopping of
motor.
2. Red and Green indicating lamps to show status of motor.
3. Suitably scaled ammeter with selector switch for each motor above
7.5 KW.
4. All auxiliary contacts for BAS.
5. Instruments for KW indication by BAS.
G. For each motor circuit, its associated circuit breaker and its starter shall be
housed in one cell or unit and interlocked so that cell door cannot be
opened and started unit cannot be withdrawn unless the breaker is in the
‘OFF’ position.
2.16 AUTOMATIC VOLTAGE STABILISER