Guardian Technologies 4270 manual Circuit CONDITION-RUNNING

Section 5

ENGINE DC CONTROL SYSTEM

CIRCUIT CONDITION-RUNNING:

With the FUEL PUMP (FP) and FUEL SOLENOID (FS) operating the engine should start. The START- STOP SWITCH (SW1) is then released. Engine con- trol circuit board action terminates DC output to the STARTER CONTACTOR (SC), which then de-ener- gizes the (SC) to end cranking.

While running, engine control circuit board action keeps Terminals 9, 10, and 11 energized which deliv- ers battery voltage to the Wire 14 circuit. This ener- gizes the FUEL PUMP (FP), FUEL SOLENOID (FS), HOURMETER (HM), and optional light or hourmeter in remote panel. This will maintain engine operation.

While running, engine control circuit board action keeps Terminal 12 (Wire 85) energized with battery voltage. Connected in parallel to Wire 85 are the LOW OIL PRESSURE SWITCH (LOS) and HIGH WATER TEMP SWITCH (HWT). The (LOS) has nor- mally closed contacts. After start-up, engine oil pres- sure will open the contacts. The HWT has normally open contacts. High coolant temperature will close the contacts. "Refer to Circuit Condition-Fault Shutdown for operation".

A voltage is induced into the Stator's POWER WIND- ING. This voltage is delivered to the Engine control circuit board Terminals 5 & 6 (via Wires 22 & 44). The engine control circuit board uses this frequency signal to determine engine speed for overspeed sensing and starter disengage.

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