Generac Power Systems 55, 75, 65 manual Test 21- Check 7.5 AMP Fuse, Test 22- Check Battery & Cables

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Section 7

DIAGNOSTIC TESTS

3. If the pump fails Step 5 or Step 6, replace the Fuel Pump.

Note: If desired, a pressure gauge can be attached to the pumps outlet side. Pump outlet pressure should be 2.0 to 3.5 psi.

4. If the pump operates normally, go to Test 31.

Figure 7-15. – Harness to Fuel Pump

TEST 21- CHECK 7.5 AMP FUSE

DISCUSSION:

If the panel-mounted 7.5 amp fuse (F1) has blown, engine cranking will not be possible.

Figure 7-16. – 7.5 Amp Fuse

PROCEDURE:

Push In on fuse holder cap and turn counterclock- wise. Then, remove the cap with fuse. Inspect the Fuse.

RESULTS:

If the Fuse element has melted open, replace the Fuse with an identical size fuse. If Fuse is good, go to Test 22.

TEST 22- CHECK BATTERY & CABLES

DISCUSSION:

If the engine won't crank or cranks too slowly, the bat- tery may be weak or discharged. See “Battery” on Page 24.

PROCEDURE:

1.Inspect the battery cables and battery posts or terminals for corrosion or tightness. Measure the voltage at the terminal of the starter contactor and verify 11-12 volts DC is available to the generator during cranking. If voltage is below 11 volts DC, measure at the battery terminals during cranking. If battery voltage is below 11 volts DC, recharge/replace battery. If bat- tery voltage is above 11 volts DC, check for proper battery cable sizing (see “BATTERY CABLES” on Page 24). If battery or cables are still suspected, connect an alternate battery and cables to the generator and retest.

2.Use a battery hydrometer to test the battery for (a) state of charge and (b) condition. Follow the hydrometer manufactur- er's instructions carefully.

RESULTS:

1.Clean battery posts and cables as necessary. Make sure bat- tery cables are tight.

2.Recharge the battery, if necessary.

3.Replace the battery, if necessary.

4.If battery is good, but engine will not crank, go to Test 23.

TEST 23- CHECK POWER SUPPLY TO

CIRCUIT BOARD

DISCUSSION:

If battery voltage is not available to the circuit board, engine cranking and running will not be possible.

If battery voltage is available to the board, but no DC output is delivered to the board's Wire 56 terminal while attempting to crank, either the circuit board is defective or the Start-Stop Switch has failed.

This test will determine if battery voltage is available to the Engine Controller circuit board. Test 24 will check the Start-Stop Switch. Test 25 will check the DC power supply to the circuit board's Wire 56 termi- nal (Receptacle J1, Pin 1).

PROCEDURE:

1.On the Engine Controller Circuit Board, locate Terminal J3 to which Wire 15 connects (see Figure 5-3 on Page 24).

2.Set a VOM to read battery voltage. Connect the meter test leads across circuit board Terminal J3 and frame ground. The meter should read battery voltage.

3.Set the VOM to measure resistance (“Rx1” scale). Connect one meter test lead to Wire 0, Pin location J1-12 on the Engine Controller Circuit Board. Connect the other test lead to a clean frame ground. “Continuity” should be measured.

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Contents Diagnostic Repair Manual Replacement Parts SafetyTable of Contents Section Exploded Views / Part Numbers Section Specifications & ChartsMagnetism Electromagnetic FieldsElectromagnetic Induction More Sophisticated AC Generator Simple AC GeneratorGenerator Operating Diagram Field Boost Generator AC Connection SystemLine Breakers 120 Volts only Reconnection for Dual Voltage Output Connection for 120 Volts OnlyStator Assembly Rotor AssemblyGeneral Battery Charge ComponentsBrush Holder Excitation Circuit ComponentsDescription Adjustment ProcedureCrankcase Breather Voltage RegulatorCheck Breather Install BreatherInstall oil vapor collector and retainer Control Panel Component IdentificationDrying the Generator Cleaning the GeneratorEffects of Dirt and Moisture Insulation Resistance TestersStator SHORT-TO-GROUND Tests Brushing and Vacuum CleaningStator Insulation Resistance Cloth or Compressed AIRMegohmmeter Testing Rotor InsulationTesting Stator Insulation Testing Rotor InsulationMeasuring DC Voltage MetersVOM Measuring AC VoltageMeasuring AC Frequency Measuring CurrentMeasuring Resistance Volt Electrical UnitsOhms LAW AmpereIntroduction Operational AnalysisCircuit CONDITION- Rest Circuit CONDITION- Priming Circuit CONDITION- Cranking Choke Heater CH Circuit CONDITION-RUNNINGCircuit CONDITION- Shutdown Sure Switch LOP Circuit CONDITION- Fault ShutdownEngine Controller Circuit Board BatteryRecommended Battery Battery CablesFuel Primer Switch START-STOP 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 Discussion ProcedureTest 1- Check NO-LOAD Voltage Frequency Test 2- Check Engine GovernorIf continuity was indicated, go to Test Governor AdjustmentTest 3- Test Excitation Circuit Breaker Test 4- Fixed Excitation TEST/ROTOR AMP DrawSet a VOM to its Rx1 scale Test 5- Wire ContinuityRe-connect Wire 11 and Wire 22 to the Voltage Regulator Set the VOM to measure AC voltageTest 6- Check Field Boost Test 7 Test Stator DPE WindingIf field boost checks good, replace the Voltage Regulator Model Ohms Test 8- Check Sensing Leads / Power WindingsAcross Wires Ohms 11S 22STest 10 Check Brushes & Slip Rings Test 9- Check Brush LeadsReplace the Rotor if it fails the test Test 11- Check Rotor AssemblyTance Tests Procedure Test 12 Check Main Circuit BreakerTest 13- Check Load Voltage Frequency Test 15 Check Battery Charge OutputTest 16 Check Battery Charge Rectifier Battery Charge Rectifier BCR is a full wave rectifierShort to Ground 10. Battery Charge RectifierTest 18 TRY Cranking the Engine Test 19- Test Primer SwitchSet a VOM to read battery voltage 12 VDC Also see Fuel Primer Switch,13. The LPG Fuel Solenoid FS Test 20- Check Fuel PumpTest 22- Check Battery & Cables Test 23- Check Power Supply to Circuit BoardTest 21- Check 7.5 AMP Fuse 17. Start-Stop Switch Test 24 Check START-STOP SwitchSet a VOM to measure DC voltage 12 VDC Test 26- Check Starter Contactor RelayTest 26A Check Starter Contactor Test 27 Check Starter MotorConditions Affecting Starter Motor Performance Tachometer Checking the PinionTools for Starter Performance Test Measuring CurrentRemove Starter Motor Testing Starter MotorTest 28- Check Fuel Supply Test BracketDiscussion LPG Models 28 LP Gas Carburetion DiagramCrank the engine. The meter should indicate battery voltage Test 29 Check Wire 14 Power SupplyTest 30 Check Wire Battery voltage is not measured, proceed to StepTest 32 Check Ignition Spark Test 31 Check Fuel Solenoid Gasoline ModelsConclusion No cylinder is weakest of the two cylinders Cylinder Balance TestTest 33 Check Spark Plugs Test 34 Check and Adjust Ignition Magnetos37. Setting Ignition Magneto Armature Air Gap Flywheel KEY Test 35 Check Valve AdjustmentAdjusting Valve Clearance Checking Flywheel MagnetInstall Rocker ARM Cover Test 36 Check CarburetionTest 37 Check Choke Solenoid 43. Connector Check Compression Adjust the regulated pressure on the gauge to 80 psiDown Test / Compression Test Repeat Steps 1 through 8 on remaining cylinderTest 39 Check OIL Pressure Switch Test 40 Test OIL Temperature SwitchIf all steps check GOOD, go to Test Test 41 Test Choke Heater Test 42 Check LPG Fuel SolenoidShort to Ground 49. Fuel Solenoid Rotor Removal Major DisassemblyENCLOSURE/PANEL Removal Stator RemovalBelt Tensioning Engine RemovalStarter 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 Flywheel Assy GT-990 QTY DescriptionControl Panel Drawing No E1013-A PANEL, TOP Control Wire ASM GRD STD ConnSwitch Spdt ON-MOM-ON Switch 6A Spdt Not ShownTwin Engine Drawing No E1014-B ASSEMBLY, OIL Fill CAP ASSEMBLY, Crankcase RVASSEMBLY, Breather ASSEMBLY, Head #1LP Regulator Drawing No E1530 SPRING-SOLENOID Plunger CASTING, Twin Regulator HousingWasher Flat M4 SOLENOID, Twin RegulatorSpecifications & Charts Nominal Resistances of Generator Windings AT 68F Generator SpecificationsEngine 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.
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