76804 2 Mercury SCREW

Illustration 1 g00291265
ETS Junction Box with oil pressure protection (OP) and water temperature protection (WT) that does not require a switchgear for use on 3200 through 3400 Engines (1) Terminal strips (TS) (2) Wiring harness (3) Time delay relay (TD2) (4) Junction box (5) Identification foil (6) Jumper between terminals (TS-2) and (TS-3) (7) Jumper between terminals (TS-3) and (TS-4) (8) Jumper between terminals (TS-4) and (TS-5) (9) Jumper between terminals (TS-6) and (TS-21) (10) Jumper between terminals (TS-5) and (TS-6) (11) Jumper between terminals (TS-7) and (TS-8) (12) Jumper between terminals (TS-8) and (TS-9) (13) Jumper between terminals (TS-9) and (TS-10) (14) Diode (D1) (15) Jumper between terminals (TS-27) and (TS-28) (16) Jumper between terminals (TS-28) and (TS-29) (17) Slave relay (SR1) (18) Slave relay (SR2) (19) Emergency stop switch (ES) (20) Time delay relay (TD1) (21) Jumper between terminals (TS-31) and (TS-32) (22) Grommets for engine oil pressure switches (23) Start/stop switch (SSS) (24) Circuit breakers (25) Mounting brackets for grommet assemblies (26) Engine oil pressure switch (OPS1)Introduction
The ETS Junction Box with oil pressure protection (OP) and water temperature protection (WT) is a partial protection system that does not require a switchgear. This system has a junction box arrangement which is designed to monitor two functions:
Engine oil pressure
Coolant temperatureThe junction box includes the following components:
start/stop switch (SSS) (23)
Slave relay (SR1) (17)
Oil pressure switch (OPS1) (26)
Emergency stop switch (ES) (19)
Time delay relay (TD1) (20)
Time delay relay (TD2) (3)The components that are listed below operate with the junction box. The components are also mounted on the engine.
Fuel shutoff solenoid (FSOS)
Water temperature contactor switch (WTS)The following components must remain de-energized in order for the engine to run with the ETS electric protection system.
Slave relay (SR1)
Fuel solenoid (FS)An air shutoff solenoid is not used because the engine overspeed is not monitored.Electrical Schematics And Wiring Diagrams
This manual contains the point-to-point wiring diagrams for the complete electric protection system and the junction box. Four types of electrical schematics for each electric protection system arrangement are shown in this service manual.
Junction box wiring diagram
IEC (International Electro-Technical Commission) schematic
JIC (Joint Industrial Council) schematic
Junction box wiring harness diagramNote: The line number that follows a component code gives the location of the component on the IEC and JIC schematics.Circuit Operation With No Faults
Engine Shutdown
When the engine is stopped, power is always available across the terminals (TD1-3) and (TD1-4) (line 11) of the time delay relay (TD1). All of the switches are in the normally open position or the normally closed positions at that time.Engine Start-up
Illustration 2 g00282739
5N-0364 Switch (1) Keyway
Table 1
Switch Position     Contacts that are closed    
START (A)     1-2 and 4-5    
RUN (B)     2-3 and 4-5    
STOP (C)     2-3 and 5-6    A toggle switch is located on the front of the junction box. The switch is spring loaded and the toggle switch is automatically returned to the RUN position. This happens when the toggle is manually released from the START. This start/stop switch ("SSS") has three positions:
START (A)
RUN (B)
STOP (C) When the start/stop switch is moved to the START position, the following events should occur in the electric circuit.
The start/stop switch closes the circuit to the starter motor.
The starter motor magnetic switch (SMMS) (line 7) closes a contact (line 2) which energizes the pinion solenoid (PS) (line 2).
The PS closes a contact (line 1) which energizes the starter motor (SM).When the toggle of the start/stop switch is held in the START position, power is always available to the starter motor until the engine begins to run. When the engine begins to run, move the start/stop switch to the RUN position. When the engine oil pressure is too low to open the oil pressure switch (OPS1), the contact across terminal (OPS1-1) and the contact across terminal (OPS1-3) (line 15) open after the 9 second time limit. The slave relay (SR1) (line 36) is energized and the engine will shut down. Refer to "Fault Circuit Operation" for the complete circuit description under these conditions.Note: If an electric starting motor and an alternator are not used to run the engine, connect the power source to the engine. Connect the positive lead of the power source to terminal (TS-1) and connect the negative lead to terminal (TS-28) of the junction box. If an electric starting motor is not used and an alternator is used, the battery can still be used to run the engine. Connect the battery cables to the studs for the power input which are located on the bottom of the power distribution box.Engine Mounted Start/Stop Switch (EMSS)
Illustration 3 g00281973
Engine mounted start/stop switch (typical example) (1) OFF position with switch terminals (B) and (C) closed. (2) ON position with switch terminals (B) and (R) closed. (3) START position with switch terminals (B), (R), and (S) closed.Some engines use an engine mounted start switch (EMSS). The EMSS replaces the start/stop switch (SSS) and the contact for the starting motor magnetic switch (SMMS) (line 2). If an engine mounted start/stop switch is provided on the engine in order to control the electric starting motor, the start/stop switch (SSS) will not be installed in the junction box.The EMSS is a start/stop switch which functions in the same manner as the SSS. When the lever of the EMSS moves to the START position, the pinion solenoid (PS) (line 2) is energized. The contacts (line 1) of the PS close. This energizes the starter motor (SM). The lever of the EMSS must remain in the START position until the engine begins to run before releasing the switch lever.Normal Stop Switch
The engine is stopped by moving the start/stop switch. The switch is moved from the RUN position to the STOP position.The following events occur in the electric circuit when the start/stop switch is moved to the STOP position.
The start/stop switch closes across contacts (SSS-5) and (SSS-6) in order to energize the time delay relay (TD) (line 24).
The current then flows through contacts (TD1-6) and (TD1-7) (line 32) of the time delay relay (TD).
Current through the TD energizes slave relay