GLASS 3836933 - Caterpillar

To prevent personal injury due to accidental starting of the engine, disconnect the batteries before doing maintenance or repair work.
Before starting the engine, do the following:1. Turn th engine control switch (ECS) to the OFF/RESET position.2. Correct any faults that may have been the cause of the emergency shutdown.3. Manually reset the air shut-off lever (at the top of the air inlet housing).4. Make sure the ESPB has been reset (button out) on both the engine junction box and generator control panel. Turn the button in the direction shown to reset.5. Turn and hold the ECS in the START position until normal oil pressure is seen on the oil pressure gauge.Fault Circuit Operation
Low Oil Pressure (OPS1)
For normal operation, make reference to the section, ENGINE START-UP.Depending on engine speed during start-up, the electronic speed switch (ESS) - crank termination (CT) will be: closed across contacts (11 and 12), providing a current path through diode (D3) to emergency stop pushbutton (ESPB) terminals (1 and 2) (line 18) (if engine speed is less than 400 rpm).closed across contacts (11 and 10) providing a current path through ESS-overspeed switch (OS) contacts (8 and 9) to ESPB terminals (1 and 2) (line 18) (if engine speed is equal to or greater than 400 rpm).Regardless of initial oil pressure and engine speed (as long as engine control switch (ECS) is held in the START position) the engine will start and run. From ESPB terminals (1 and 2) (line 18), current flows through the water temperature switch (WTS) (line 18) through normally closed (N.C.) engine failure relay (ENFR) contacts (2 and 8) (line 23) through ECS contacts (1 and 2) through ESPB (panel mounted) terminals (1 and 2) (line 23) through ECS contacts (12 and 11) (line 24) to slave relay (SR1) (line 36). Relay (SR1) energizes to close its contacts (1 and 3) (line 43) and energize the fuel solenoid (FS) (line 43). This provides fuel to the engine.If at this point the ECS is released from the START to RUN position and there is not enough initial oil pressure to close oil pressure switch (OPS1) across contacts (1 and 2) (line 13), then the opening across ECS contacts (11 and 12) will de-energize SR1 and FS. This shuts off fuel to the engine, resulting in engine shutdown.With OPS1 closed across its contacts (1 and 3), the current path will be also through ECS contacts (9 and 10) (line 15) to oil pressure relay (OPR). Relay (OPR) energizes to close its contact (5 and 8) (line 16). If ESS (CT) has closed across its contacts (11 and 10) to arm the circuit to OPR contacts (5 and 8) through diode (D13) (line 17) to engine failure relay (ENFR) (line 12) and engine failur light (EFL) (line 13). Relay (ENFR) energizes to close its contacts (7 and 4) (line 13) which latches ENFR and EFL through ECS contacts (5 and 6).When the ECS is turned to the OFF/RESET position from the RUN position, the relay