SPOOL-BYPASS 7G4998 - Caterpillar

The bus bars and current transformer will have high voltage when the generator is in operation with the circuit breaker in the switchgear, closed. If the installation has more than one switchgear, and the other generators are in operation, the bus bars can have high voltage with the circuit breaker in the switchgear open. Be very careful when troubleshooting for voltage in the switchgear.
Before any work or tests are done in the switchgear, be sure you understand the principles of the operations.Many of the electrical problems are caused by mechanical problems. Make a careful inspection of the total electric system and separate the mechanical problems from the electric problems. Find the operation problem and use the wiring diagrams with the troubleshooting to verify the probable cause.All of the tests in the verification procedures can be made with a multi-tester (volt ohmmeter) but most of the tests can be made with a 5P7277 Tester for voltage and an 8S4627 Circuit Continuity Tester.The relays with the clear covers are all the same and can be used in any relay socket.It may be necessary to make a reference to the list of abbreviations for the names of the parts, switches, relays and lights that are on the schematics of the engine control group (ECG).ACSAUTOMATIC CONTROL SWITCHARARMING RELAYASOAIR SHUTOFF SOLENOIDBATT.BATTERYBCBATTERY CHARGERCBCIRCUIT BREAKERCB/aNORMALLY OPEN CIRCUIT BREAKER AUXILIARY CONTACTCB/bNORMALLY CLOSED CIRCUIT BREAKER AUXILIARY CONTACTCBRCIRCUIT BREAKER RELAYCCRCYCLE CRANK RELAYCCMCYCLE CRANK MODULECCTCYCLE CRANK TIMERCCRCOOLDOWN RELAYCCMCOOLDOWN MODULECDTCOOLDOWN TIMERCLLCOOLANT LEVEL LOW LIGHT (PREALARM)CSCIRCUIT BREAKER CONTROL SWITCHCTSCRANK TERMINATION SWITCHCCIRCUIT BREAKER CLOSED LIGHTDDIODEDCADIRECT CURRENT READING AMMETERDSSDUAL SPEED SWITCHFPFUEL PRESSUREGCRGOVERNOR CONTROL RELAYGOV.GOVERNORGSGOVERNOR SWITCHGSMGOVERNOR SPEED MOTORHWTHIGH WATER TEMPERATURE LIGHT (PREALARM)ICINITIATIVE CONTACTLCLCOOLANT LEVEL LOW SWITCH (PREALARM)LFLLOW FUEL LEVEL LIGHT (PREALARM)LFSLOW FUEL LEVEL SWITCH (PREALARM)LOLLOW OIL LEVEL LIGHT (PREALARM)LWTLOW WATER TEMPERATURE SWITCHOCIRCUIT BREAKER OPEN LIGHTOCLOVERCRANK LIGHTOCROVERCRANK RELAYOCTOVERCRANK TIMEROLLOIL LEVEL LOW LIGHT (PREALARM)OPLLOW OIL PRESSURE LIGHTOPPLOW OIL PRESSURE PREALARM SWITCHOPRLOW OIL PRESSURE RELAYOPSLOW LUBE OIL PRESSURE SWITCHOPTOIL PRESSURE TIMEROPTDOIL PRESSURE TIME DELAYOSLOVERSPEED LIGHTOSROVERSPEED RELAYOSSOVERSPEED SWITCHPSPRESSURE SWITCHPSWPRESSURE SWITCHRPLREVERSE POWER LIGHTRPRREVERSE POWER RELAYRPREREVERSE POWER RELAY RESET SWITCHRPRXREVERSE POWER RELAY AUXILIARYRRRUN RELAYSHTCSHUNT TRIP COILSRSHUTDOWN RELAYSSSHUTDOWN SOLENOIDSUP.SUPPRESSORTTRIP POSITIONWLTLOW WATER TEMPERATURE LIGHT (PREALARM)WTLWATER TEMPERATURE LIGHT (HIGH)WTPHIGH WATER TEMPERATURE SWITCH (PREALARM)WTRWATER TEMPERATURE RELAY (HIGH)WTSWATER TEMPERATURE SWITCH (HIGH)
ENGINE CONTROL GROUP (ECG)
RELAY PRINTED CIRCUIT SOCKET BOARD Problems
1. ENGINE WILL NOT CRANK.2. ENGINE OVERCRANK DOES NOT OPERATE.3. ENGINE WILL NOT TERMINATE CRANKING.4. ENGINE RUNS BUT GOVERNOR SWITCH WILL NOT CHANGE ENGINE SPEED.5. NO CONTROL VOLTAGE TO 2301 GOVERNOR.6. ENGINE SPEED CONTROL (2301 GOVERNOR) WILL NOT CHANGE ENGINE SPEED.7. NO VOLTAGE TO 2301 GOVERNOR.8. ENGINE DOES NOT STOP WHEN OIL PRESSURE IS TOO LOW.9. ENGINE DOES NOT STOP WHEN COOLANT TEMPERATURE IS TOO HIGH.10. ENGINE DOES NOT STOP WHEN ENGINE SPEED (RPM) IS TOO FAST.11. NOT NORMAL ENGINE CONDITION LIGHT IS NOT ON AFTER NOT NORMAL CONDITION STOPPED THE ENGINE.12. ENGINE WILL NOT STOP WHEN AUTOMATIC CONTROL SWITCH (ACS) IS MOVED TO THE STOP POSITION.13. ENGINE WILL NOT STOP WHEN AUTOMATIC CONTROL SWITCH (ACS) IS MOVED TO THE OFF/RESET POSITION.14. ENGINE WILL NOT AUTOMATICALLY START.15. ENGINE DOES NOT COOL ENOUGH BEFORE IT IS AUTOMATICALLY