BANGLADESH POWER DEVELOPMENT BOARD TENDER ... - BPDB

The test block shall be of the back- connected plug or stud type with removalcovers. All test blocks shall be provided with suitable circuit identification and shallbe arranged to isolate completely the instrument from the instrumenttransformers and other external circuits so that no other device will be affected,and means shall be provided for testing either from an external source of energyor from the instrument transformers.The test blocks shall be arranged so that the current transformer secondarycircuits cannot be open circuited if any position while the test plugs are in place,being inserted, or being removed. Three test plugs for each type of blockfurnished shall be furnished.(8) Control SwitchThe handles of control switches for circuit breakers, disconnecting switches andauxiliary equipment shall be of the stick type, the handles of the control switchesfor adjustment shall be of the oval type, and the handles of the selector switchesshall be of the flower type. Every switch shall have engraved identification numberon the knob in white.(9) Internal wiringa. WireThe internal wiring shall be made with PVC wire of 2.5 sq. mm copper stranded orlarger, and solder- less terminals shall be used for connection.The secondary circuit of C.T. and P.T. shall be wired with PVC wire 4.0 sq. mm(minimum) copper stranded.b. Colour CodingThe colour-coding shall be made as follows:- Secondary circuit of potential transformer Red-Secondary circuit of current transformer Black- DC control circuit Blue- AC control circuit Yellow- Main circuit Yellow- Earthing circuit Greenc. Terminal blocksTerminal blocks to be connected with internal wiring and external wirings shallhave the cover (s) and identification numbers.(10) The secondary circuit of P.T. for metering shall be provided with fuse.Earth The C.T. and P.T. secondary circuits shall only be grounded inside the paneland appropriate Testing facility shall be provided.A handset of flush type for paging system shall be installed on the slant part ofGhorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)90