Utility Failure And Engine Cranking - Generac Power Systems CorePower Repair Manual

Home standby generator

Table of Contents

ENGINE/DC CONTROL

When the utility sensing voltage drops out the controller will start a 10 second timer. If the voltage does not return fully of is below

60 percent of normal the generator will start to crank.

The controller action delivers 12 VDC to the starter contactor via wire 56. When the starter contactor energizes, it delivers battery

voltage to the starter motor and the engine will crank.

Wire 56 also delivers 12 VDC to the choke solenoid. The controller action grounds wire 90 to actuate the choke solenoid cyclically

during cranking. The controller action will remove wire 90 from ground during normal running operation.

The controller delivers 12 VDC to the fuel solenoid during cranking and will continue to during normal running operation.

As the engine cranks a magnet on the flywheel induces a high voltage into the engines ignition magneto (IM). A spark is produced

that jumps the spark plug gap.

During cranking residual magnetism from the rotor induces a voltage into the stator (blue) excitation wires and the (green and white)

sensing wires. Voltage from the excitation wires power up the voltage regulator.

STATOR

BLK

RED

BLU

LEGEND

BA - BRUSH ASSEMBLY

BC - BATTERY CHARGER

C1 - 4 POS. CONNECTOR

CB - CIRCUIT BREAKER,

MAIN OUTPUT

GND - GROUND

HTO - HIGH TEMPERATURE SWITCH

IM - IGNITON MODULE

LOP - LOW OIL PRESSURE SWITCH

SC - STARTER CONTACTOR

SM - STARTER MOTOR

SP1 - SPARK PLUG

- SPLICE

- SPLICE INTERCONNECT

NOTE: ALL WIRES 18 AWG

300V UL LISTED UNLESS

SHOWN OTHERWISE

AWG SIZE

PART 4