Salient Technical Features
A. Brief Scope of Work
The scope of work includes design, manufacture, shop testing, supply, transportation &
complete insurance, handling and storage at site, including dismantling & shifting of
existing Switchgears/MCCs, and complete installation, testing and commissioning of the
following:
415 Volt Switchgears
415 Volt Motor Control Centers
415 Volt AC Distribution Boards
The Scope also includes supply & installation of necessary hardware such as Lugs,
Glands, Identification tags, Cable ties, etc. required for relugging & termination of
existing Power & control cables.
B. General Information to Bidder
i). Offered Switchgear/MCC should be suitable for replacing existing Switchgear/MCC.
ii). The bidder is advised to visit Unchahar site before submitting the techno-commercial
bid to get acquainted with the system and get detail information of existing
Switchgear/MCCs, its connection, orientation, matching with existing foundation plan and
location etc. if required.
iii). The bidder shall offer Switchgear/MCC suitable for replacement of existing
Switchgear/MCC i.e. there should be no need to change the existing foundation, Cable
connection of existing cables, etc.
C. Technical Features
The short-time fault withstand rating of the switchgears shall be 45kA (RMS) for one
second and the Dynamic withstand rating shall be 105kA (peak).
The reference ambient temperature is 50
0
C for all the equipment.
All switchboards shall be of metal enclosed, indoor, floor-mounted, free-standing type of
bolted design. All switchboards shall be divided into distinct vertical sections (panels),
each comprising of busbar compartment, switchgear / feeder compartment, cable
compartment or cable alley and control compartment. Cable terminations located in
cable alley shall be designed to meet the Form 4b as per IEC 61439 for safety purpose.
All ACDBs shall be of fixed type. All 415V circuit-breaker modules and contactor
controlled motor modules shall be of fully draw out type having distinct 'Service' and
'Test' positions.
The circuit breaker rack in and rack out from Service to Test, Test to Isolated position or
vice-versa shall be possible only in the door closed position.
All draw-out modules shall be provided with “Closed door operation” feature wherein
movement of the module from “Isolated” position to “Service” position & vice-versa and
power ON / OFF operation of the module shall be possible only with the module door
closed condition.
The Circuit Breakers / Contactors shall be of air break type & should conform to the
requirements of IS 13947 / IEC 60947. MCCB shall be provided for 100A and above
upto 630A supply feeders. The motor feeders for 110KW & above shall be Air Circuit
Breaker controlled.
All the protective relays associated with the Circuit breaker modules shall be of
Numerical communicable type IEC 61850 compliant for Protection, Control, Metering
and Status monitoring.