LT Switchgears & LT Busducts Package for Tanda TPP Stage-II (2X660MW)

Brief Scope of Work

The scope includes design, manufacture, shop testing, packing, transportation to the site and complete insurance, port clearance, port handling & customs reconciliation (as applicable), receipt, handling and storage at site, complete installation, testing and commissioning of entire LT Switchgears and LT Busducts as detailed in the bidding document No.CS-9562-206-2 for LT Switchgear and LT Busducts package for Tanda TPP Stage-II (2X660MW).

Salient Technical Features

The short-time fault withstand rating of the switchgears shall be 50kA (RMS) for one second and the Dynamic withstand rating shall be 105kA (peak).

The reference ambient temperature is 50⁰C 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. Entire busbar system shall be insulated with PVC sleeves. Cable terminations located in cable alley shall be designed to meet the Form IV b Type 7 (as per IEC 61439) for safety purpose. The termination for each module shall have its own integral glanding facility.

All ACDBs, DCDBs & Solenoid Valve DBs shall be of Fixed Module type. All 415V Circuit breaker modules and MCC modules shall be of fully draw out type having distinct “Service” and “Test” positions.

The Circuit Breakers / Contactors shall be of air break type & should conform to the requirements of IS / IEC 60947. MCCB shall be provided for 100A, 125A, 160A, 250A & 400A supply feeders. The motor feeders for 110kW & above shall be Air Circuit Breaker controlled.

The circuit breaker will normally be controlled from remote control panels (employer’s DDCMIS) through closing and shunt trip coils. The control of the breakers shall also be possible from the switchgear SCADA system. All the protective relays associated with the Circuit breaker modules shall be of Numerical communicable type for Protection, Control, Metering and Status monitoring. All the numerical relays shall have communications on three ports, local front port communication to laptop and dual ports on IEC 61850 to communicate with the data concentrator through LAN. The auxiliary contacts of the critical MCCB shall be fed to the digital inputs available in the numerical relays of Incomer / bus coupler / motor circuit breaker feeders, for integration into the numerical relay network. The vendor’s scope includes Numerical relays, Ethernet switches, Data cables and Laptops (for programming of Numerical relays) for the above purpose.