Foster Cold-Room Technicians Hand Book - Nccvmtc.org

2.Alarm ConditionThere are alarm circuits (a) in the cold panel forhigh temperature inside the cold-room and (b) in the generatorpanel for low engine tube oil pressure and/or hightemperature and failure of the engine to start (Detail atitem: 4 at page 3).When temperature inside the cold room rises to or above thepresent temperature thermostat T1 operates. Its contactsclose and operate light and audio alarm (If any) and alsoalarm relay C1. The alarm continues even If alarm conditionis over.The alarm should go off when reset button b2 is pressedand temperature inside the cold-room panel has come down. It willnot go off till the temperature the temperature inside the cold room comes down below +10 0 C even though b2 is pressed.3 Mains Power Supply Failure Condition (Generator Panel)As soon as the main power fails. Relay N1 and NK drop off andlamp X2 extinguishes.a) When MAN/AUT selector is at 0 OFF position, thegenerator will not start automatically and cannot bestarted manually also.b) When MAN/AUT selector is at (MANUAL) positionThe generator-set will not start automatically but can bestarted manually by pressing START button. On pressingthe start button relay RH1 operates and the starter ofthe engine (M) works and starts the engine. Release thestart button when the engine gains speed. When thegenerator has built up required voltage relay T3 willoperate after the present time (10 sec) (Ref Diag 2,3)and will turn operate relay GK, which will extend thegenerator power supply to R&O output terminals for coldroom panel (consumption).28