RING-PISTON 3149962 - Caterpillar

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)