Generac Power Systems 75, 55, 65 manual Circuit CONDITION- Cranking

Page 22

Section 5

ENGINE DC CONTROL SYSTEM

CIRCUIT CONDITION- CRANKING:

When the START-STOP-SWITCH (SW1)or REMOTE PANEL START SWITCH is held at “START” position, Wire 17 from the Engine controller circuit board is con- nected to frame Ground. Circuit board action will then deliver battery voltage to a STARTER CONTACTOR RELAY (SCR) via wire 56, and to a automatic CHOKE SOLENOID (CS) via Wire 90.

When battery voltage energizes the STARTER CON- TACTOR RELAY (SCR), Its contacts close and battery output is delivered to the STARTER CONTACTOR (SC) via Wire 16. The STARTER CONTACTOR (SC) ener- gizes and its contacts close, battery output is delivered to the STARTER MOTOR (SM) via Wire 16.The STARTER MOTOR energizes and the engine cranks.

When the STARTER CONTACTOR RELAY (SCR) closes, Battery voltage is also delivered to the circuit board pin location J1-13 via Wire 16. This voltage is reduced and used for field boost and is outputted from pin location J1-9.

While cranking, the CHOKE SOLENOID (CS) is ener- gized cyclically by circuit board action (two seconds on, two seconds off).

Also while cranking, circuit board action energizes CIRCUIT BOARD TERMINAL J2 and delivers battery voltage to the Wire 14/14A circuit. This energizes the FUEL PUMP (FP) ,FUEL SOLENOID (FS) and CHOKE HEATER (CH) and optional light or hourmeter in remote panel.

Circuit board action holds open Wire 18A to common ground. The Magneto will induce a spark during cranking.

Page 20

Page 21 Page 23
Image 22
Page 21 Page 23
Contents Diagnostic Repair Manual Safety Replacement PartsTable of Contents Section Specifications & Charts Section Exploded Views / Part NumbersElectromagnetic Fields MagnetismElectromagnetic Induction Simple AC Generator More Sophisticated AC GeneratorGenerator Operating Diagram Generator AC Connection System Field BoostLine Breakers 120 Volts only Connection for 120 Volts Only Reconnection for Dual Voltage OutputRotor Assembly Stator AssemblyExcitation Circuit Components Battery Charge ComponentsBrush Holder GeneralVoltage Regulator Adjustment ProcedureCrankcase Breather DescriptionControl Panel Component Identification Install BreatherInstall oil vapor collector and retainer Check BreatherInsulation Resistance Testers Cleaning the GeneratorEffects of Dirt and Moisture Drying the GeneratorCloth or Compressed AIR Brushing and Vacuum CleaningStator Insulation Resistance Stator SHORT-TO-GROUND TestsTesting Rotor Insulation Testing Rotor InsulationTesting Stator Insulation MegohmmeterMeasuring AC Voltage MetersVOM Measuring DC VoltageMeasuring Current Measuring AC FrequencyMeasuring Resistance Ampere Electrical UnitsOhms LAW VoltOperational Analysis IntroductionCircuit CONDITION- Rest Circuit CONDITION- Priming Circuit CONDITION- Cranking Circuit CONDITION-RUNNING Choke Heater CHCircuit CONDITION- Shutdown Circuit CONDITION- Fault Shutdown Sure Switch LOPBattery Cables BatteryRecommended Battery Engine Controller Circuit BoardSTART-STOP Switch Fuel Primer SwitchAMP Fuse Starter Contactor Relay Starter Motor Troubleshooting Flowcharts Troubleshooting Flowcharts Troubleshooting Flowcharts Troubleshooting Flowcharts Troubleshooting Flowcharts Troubleshooting Flowcharts Troubleshooting Flowcharts Troubleshooting Flowcharts Troubleshooting Flowcharts Troubleshooting Flowcharts Troubleshooting Flowcharts Test 2- Check Engine Governor ProcedureTest 1- Check NO-LOAD Voltage Frequency DiscussionTest 4- Fixed Excitation TEST/ROTOR AMP Draw Governor AdjustmentTest 3- Test Excitation Circuit Breaker If continuity was indicated, go to TestSet the VOM to measure AC voltage Test 5- Wire ContinuityRe-connect Wire 11 and Wire 22 to the Voltage Regulator Set a VOM to its Rx1 scaleTest 7 Test Stator DPE Winding Test 6- Check Field BoostIf field boost checks good, replace the Voltage Regulator 11S 22S Test 8- Check Sensing Leads / Power WindingsAcross Wires Ohms Model OhmsTest 9- Check Brush Leads Test 10 Check Brushes & Slip RingsTest 12 Check Main Circuit Breaker Test 11- Check Rotor AssemblyTance Tests Procedure Replace the Rotor if it fails the testBattery Charge Rectifier BCR is a full wave rectifier Test 15 Check Battery Charge OutputTest 16 Check Battery Charge Rectifier Test 13- Check Load Voltage Frequency10. Battery Charge Rectifier Short to GroundAlso see Fuel Primer Switch, Test 19- Test Primer SwitchSet a VOM to read battery voltage 12 VDC Test 18 TRY Cranking the EngineTest 20- Check Fuel Pump 13. The LPG Fuel Solenoid FSTest 23- Check Power Supply to Circuit Board Test 22- Check Battery & CablesTest 21- Check 7.5 AMP Fuse Test 24 Check START-STOP Switch 17. Start-Stop SwitchTest 26- Check Starter Contactor Relay Set a VOM to measure DC voltage 12 VDCTest 27 Check Starter Motor Test 26A Check Starter ContactorConditions Affecting Starter Motor Performance Measuring Current Checking the PinionTools for Starter Performance Test TachometerTest Bracket Testing Starter MotorTest 28- Check Fuel Supply Remove Starter Motor28 LP Gas Carburetion Diagram Discussion LPG ModelsBattery voltage is not measured, proceed to Step Test 29 Check Wire 14 Power SupplyTest 30 Check Wire Crank the engine. The meter should indicate battery voltageTest 31 Check Fuel Solenoid Gasoline Models Test 32 Check Ignition SparkCylinder Balance Test Conclusion No cylinder is weakest of the two cylindersTest 34 Check and Adjust Ignition Magnetos Test 33 Check Spark Plugs37. Setting Ignition Magneto Armature Air Gap Checking Flywheel Magnet Test 35 Check Valve AdjustmentAdjusting Valve Clearance Flywheel KEYTest 36 Check Carburetion Install Rocker ARM CoverTest 37 Check Choke Solenoid 43. Connector Repeat Steps 1 through 8 on remaining cylinder Adjust the regulated pressure on the gauge to 80 psiDown Test / Compression Test Check CompressionTest 40 Test OIL Temperature Switch Test 39 Check OIL Pressure SwitchIf all steps check GOOD, go to Test Test 42 Check LPG Fuel Solenoid Test 41 Test Choke HeaterShort to Ground 49. Fuel Solenoid Stator Removal Major DisassemblyENCLOSURE/PANEL Removal Rotor RemovalEngine Removal Belt TensioningStarter Removal FLYWHEEL/MAGNETO Removal Page Section Exploded Views / Part Numbers Part NO. QTY Description Enclosure Drawing No E1011-B QTY Description Sheet Metal Drawing No E1012-E QTY Description Flywheel Assy GT-990Control Panel Drawing No E1013-A Switch 6A Spdt Not Shown Wire ASM GRD STD ConnSwitch Spdt ON-MOM-ON PANEL, TOP ControlTwin Engine Drawing No E1014-B ASSEMBLY, Head #1 ASSEMBLY, Crankcase RVASSEMBLY, Breather ASSEMBLY, OIL Fill CAPLP Regulator Drawing No E1530 SOLENOID, Twin Regulator CASTING, Twin Regulator HousingWasher Flat M4 SPRING-SOLENOID PlungerSpecifications & Charts Generator Specifications Nominal Resistances of Generator Windings AT 68FEngine Speeds and Voltage Specifications Page Electrical Data Electrical Data PO BOX 297 WHITEWATER, WI

65, 75, 55 specifications

Generac Power Systems has established itself as a leader in power generation, offering a range of high-performance generators suited for residential and commercial applications. Among its lineup, the Generac 55, 65, and 75 kW generators stand out for their reliability, efficiency, and advanced features.

The Generac 55 kW generator is designed to provide a powerful backup solution for medium to large homes or small businesses. It features a robust engine that delivers dependable performance while maintaining fuel efficiency. One of its key characteristics is the True Power Technology, which produces clean and stable power, ensuring that sensitive electronic devices run smoothly without risk of damage. This generator is equipped with a fully automatic transfer switch, allowing for seamless power transition during outages, with minimal disruption.

Moving to the 65 kW model, it offers increased capacity while retaining the fundamental qualities of the 55 kW version. This unit is particularly suited for larger homes or commercial applications that require greater power demands. The 65 kW generator utilizes Generac’s G-Force engine, known for its durability and reduced maintenance needs. Advanced features such as remote monitoring capabilities allow users to check the generator's status from anywhere, providing peace of mind and convenience.

The 75 kW generator takes performance to the next level, making it ideal for even more significant power needs. It is engineered for both quiet operation and enhanced performance, accommodating a wide range of requirements from residential to larger commercial operations. The 75 kW model includes a full-load voltage regulation system that maintains stable power output under varying loads, safeguarding appliances and equipment.

All three models incorporate advanced air-cooled technology, which enhances their efficiency and operational lifespan. Additionally, their corrosion-resistant enclosures ensure durability even in harsh weather conditions, making them suitable for diverse environments. The intuitive LCD display on each unit provides critical information, including runtime hours and maintenance reminders, empowering users with easy access to the generator's performance data.

Overall, Generac Power Systems' 55, 65, and 75 kW generators represent a commitment to quality, reliability, and innovation in backup power solutions. They are designed to meet the demands of modern power consumption while ensuring peace of mind through robust engineering and advanced technology. Whether for home use or commercial applications, these generators provide an effective means to stay prepared for unexpected power outages.
Top Page Image Contents