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
M PULSE RELAYS
Pulse relays shall be suitable AC or DC operation as per system
manufacturer Normal practice. The operation voltage may be 240V 50Hz
or 24V DC
The pulse relay shall be suitable for actuation manual through built-in
Push button.
2.13 MOTOR PROTECTION
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.
2.14 ELECTRONIC SOFT STARTERS
Where these starters do not fall under the electrical sub-contractor’s scope of
work, the specifications may be used for all co-ordination works.
The concerned factory manufacturing the equipment must be ISO 9001 certified
for quality assurance and the product supplied shall bear the CE mark.