ENGINE PROTECTIVE DEVICES
The engine shall be equipped with protective devices to provide warning and automatic shut-down under the following conditions:-
(a) Low lubricating oil pressure – warning and shut-down
(b) High lubricating oil temperature – warning and shut-down
(c) High exhaust temperature – warning and shut-down
(d) High jacket water temperature – warning and shut-down
(e) Low radiator water level – warning and shut-down
(f) Fail to start – warning and shut-down
(g) Over speed – shut-down
(h) Low battery voltage – warning
(i) Low fuel level (1st.stage) – warning
(j) Low fuel level (2nd.stage) – shut-down
(k) Fuel pump runaway – warning and shut-down by shut-off fuel supply to the engine
Protective devices provided shall form the generator set monitoring, protection and control module as in Section 14.0 – Generator Set Control Board and Generator Set Controllers. The set values for the above warning and shut-down protective devices shall be of the manufacturer’s recommendations. The ‘fail to start’ warning and shut-down protective devices shall operate if the engine fails to start within a adjustable pre-set time and stop the automatic starting cycle to avoid successive depletion of the battery charge. The time shall be set to allow for 6 attempts in starting each with a rest interval of half the time setting of the attempt to start. Under any of the above conditions, a common alarm bell of 250 mm diameter installed at the generator set control board and a similar alarm bell of weatherproof type installed externally above the generator room door shall sound. In addition, indication lamps showing operation of each engine protective devices shall also be provided at the generator set control board.
Upon receiving the signal from the fire detection system in the generator room, the generator set, if it is operating, shall automatically shut-down. If the generator set is not operating, the generator set shall be locked out from starting. In addition, the fuel supply lines shall be automatically isolated and alarm shall be activated. All control/signalling cables from the generator set control board to the generator set, fuel level sensor switches, main switchboard, etc. shall be multicore 2.5 sq.mm pvc/swa/pvc cables. Sufficient numbers of cores plus 20% or minimum 6 cores for spare
shall be provided to serve their purpose. The cable shall be laid on the hot-dip galvanized cable tray which shall be installed on the side wall of the cable trenches. If exposed the cable shall be laid along side with the mains cable on the suspended hot-dip galvanised cable tray. All cores shall be properly labelled with number sleeves and terminated at the rail mounting terminal blocks housed in metalclad box. In the generator set control board and main switchboard, the terminal blocks shall be of the type with isolating knife links. No two or more cores shall be terminated in the same terminal block. The Electrical Contractor shall ensure and verify with simulation tests and function checks for the operations of each the above protective devices in the presence of the S.O’s Representative during testing and commissioning at site on completion of the generator set erection. All tests shall be carried out and recorded, and test results shall be submitted to S.O.’s Representative.