Safety Read This Manual Thoroughly Throughout this publication and on tags and decals This diagnostic manual has been written and published affixed to the generator, DANGER, WARNING, and by Generac to aid dealer technicians and company CAUTION blocks are used to alert personnel to special service personnel when servicing the products described instructions about a particular operation that may be herein.
Table of Contents Safety ................ ii Test 9 – Test Brushed Stator Windings ....14 Read This Manual Thoroughly ........ii Test 10 – Check Load Voltage & Frequency ..14 Replacement Parts ........... ii Test 11 – Check Load Watts & Amperage .....14 Rotor and Stator Resistance Tables ......
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Table of Contents Test 17 – Check START-RUN-STOP Switch Wiring Diagram and Electrical Schematic, (410/426cc Engine) ..........28 XP10000E Drawing No. 0H7214-D ....... 80 Wiring Diagram and Electrical Schematic, Test 18 – Test OFF-ON Switch .......28 XG4000 Drawing No. 0H3339-E ......84 Test 19 –...
Brushless Capacitor Excitation Section 1 Introduction NOTE: This will only increase from no load to full load and will stop increasing at that point. Figure 1-1. A typical brushless type portable NOTE: The voltage of a brushless capacitive discharge generator needs 4 major components to function: a prime generator will start low and increase as load is applied.
Section 1 Brushless Capacitor Excitation Operation AC Power Winding Output A maintained voltage is induced into the stator AC power Startup windings. When electrical loads are connected across When engine started, residual/permanent the AC power windings to complete the circuit, current magnetism from the rotor induces a voltage into (a) the can flow in the circuit.
Section 1 Brushless Capacitor Excitation Troubleshooting Flowcharts Introduction Use the Flow Charts in conjunction with the AC Diagnostic Tests . Test numbers used in the flow charts correspond to the numbered tests in the AC Diagnostic Tests . The first step in using the flow charts is to identify the correct problem on the following pages.
Section 1 Brushless Capacitor Excitation Problem 2 – Voltage & Frequency Are Both High or Low GO TO FREQUENCY GOOD, LOW OR PROBLEM 1 RESIDUAL VOLTAGE TEST 30 – CHECK & ADJUST ENGINE GO TO NO-LOAD FREQUENCY & VOLTAGE GOOD BUT GOVERNOR, 410cc ENGINE PROBLEM 3 THEY DROOP TO MUCH WHEN LOAD IS APPLIED...
Direct Excitation (Brush Type) Section 2 Introduction Brush Holder and Brushes The brush holder has a positive (+) and a negative (-) Figure 2-1. A typical brush type portable generator brush, and is retained to the rear bearing carrier by needs 4 major components to function: prime mover, means of two Taptite screws.
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Section 2 Direct Excitation (Brush Type) via Wire 4, and the positive brush and slip ring. This TO LOAD excitation current flows through the rotor windings and through the negative (-) slip ring and brush on Wire 0. MLB = MAIN LINE CIRCUIT BREAKER The greater the current flow through the rotor windings, the more concentrated the lines of flux around the rotor...
Section 2 Direct Excitation (Brush Type) Troubleshooting Flowcharts Introduction Use the Flow Charts in conjunction with the AC Diagnostic Tests . Test numbers used in the flow charts correspond to the numbered tests in the AC Diagnostic Tests . The first step in using the flow charts is to identify the correct problem on the following pages.
Section 2 Direct Excitation (Brush Type) Problem 6 – Voltage & Frequency Are Both High or Low FREQUENCY GOOD, GO TO LOW OR RESIDUAL PROBLEM 5 VOLTAGE NO-LOAD FREQUENCY & TEST 29 – CHECK & ADJUST ENGINE GO TO VOLTAGE GOOD BUT THEY GOVERNOR, 220cc ENGINE PROBLEM 7 DROOP TOO MUCH WHEN...
AC Diagnostic Tests Section 3 Test 2 – Check Main Circuit Breaker Introduction Perform the Diagnostic Tests in this section in Procedure conjunction with Brushless Troubleshooting The generator has circuit breakers located on the control Flowcharts or the Brush Type Troubleshooting panel.
Section 1 AC Diagnostic Tests Results Procedure If any other reading than CONTINUITY was Remove positive and negative wires connected to measured, further troubleshooting needs to be done the brush assembly. to determine if it is the receptacle or the wiring. Connect one jumper wire to where the positive If receptacles test good, refer to flow chart.
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Section 1 AC Diagnostic Tests While the unit is running connect one jumper wire Record DC amperage measured. Approximately to the negative terminal of the battery and connect 0.22 DC amps should be measured. the other jumper wire to the positive terminal. NOTE: The DC voltage of the battery divided by the Record voltage measured on Wires 2 and 6 on the resistance measured in Step 17 will give a calculated...
Section 1 AC Diagnostic Tests Test 5 – Field Flash Alternator IMPORTANT NOTE: Do NOT energize the capacitor for more than 1 second at a time. (Configuration “A” Only) Momentarily turn on energizing cord (one second). General Theory Disconnect energizing cord from capacitor. The alternator utilizes residual magnetism within the Carefully re-connect the DPE winding leads to the windings to charge the capacitor.
Section 1 AC Diagnostic Tests Test 6 – Check Capacitor IMPORTANT NOTE: A capacitor that has gone bad has a tendency to explode. Use caution when dealing with an General Theory exploded capacitor. The gel from inside a capacitor can cause skin irritation.
Section 1 AC Diagnostic Tests Test 8 – Test Brushless Stator Test 9 – Test Brushed Stator Windings Windings General Theory General Theory Most brushed stators have three main windings that are needed to produce voltage. The alternator has two main The brushless stator has three internal windings, two power windings which supply power to the load and a main power windings and a DPE winding.
Section 1 AC Diagnostic Tests Results Verify all material is clear of the alternator before proceeding. If unit is overloaded, reduce load. Set START-STOP-RUN switch to START. If load is within limits but frequency and voltage still drop excessively, refer to flow chart. Figure 3-10 for location of adjustment screw.
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Section 1 AC Diagnostic Tests Place one test meter lead on contact 2 and the other on contact 3. If CONTINUITY is not measured, rock the switch. If CONTINUITY is still not measured, replace switch. Place one test meter lead on contact 5 and the other on contact 6.
EFI Engine Control Diagnostic Tests Section 4 Basic EFI Theory Engine Requirements Electronic Fuel Injection was first introduced to The correct proportion of fuel is required to be mixed with automobiles in the late 1960s. EFI is not new, as its roots the incoming air for efficient operation.
Section 1 EFI Engine Control Diagnostic Tests Air Metering and Measurement Air Temperature The amount of air entering the engine is controlled by a This is a secondary input required especially on speed conventional butterfly valve located in a throttle body density systems.
Section 1 EFI Engine Control Diagnostic Tests EFI Fault Code Diagnostics There are 3 failure levels: • Level 1 will flash and the generator will run. There Fault Indicator Light may be a slight impact on performance. When the EFI system is connected to a power source •...
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Section 1 EFI Engine Control Diagnostic Tests This page intentionally left blank. Diagnostic Repair Manual...
Engine Diagnostic Tests Section 5 Diagnostic Flow Charts Use the Flow Charts in conjunction with the numbered tests in this section. Test numbers used in the flow charts correspond to the numbered tests. The first step in using the flow charts is to identify the correct problem on the following pages.
Section 5 Engine Diagnostic Tests Problem 11 – Engine Turns Over But Will Not Start (208/389/420cc Non-EFI Engines) CHECK TEST 20 – TEST 28 – REMOVE CHECK FUEL FUEL GOOD CHECK WIRE 18 / SHUTOFF GOOD SUPPLY SPARK SHUTDOWN LEAD VALVE SPARK SPARK...
Section 5 Engine Diagnostic Tests Problem 13 – Engine Will Not Crank (220/410/530cc Engines with Electric Start) TEST 16 – CHECK TEST 17 – CHECK TEST 15 – CHECK NO VOLTAGE VOLTAGE AT START-RUN-STOP BATTERY GOOD MEASURED STARTER SWITCH & CABLES CONTACTOR 12 VDC MEASURED...
Section 5 Engine Diagnostic Tests Problem 15 – Engine Cranks But Will Not Start (220/410/530cc Non-EFI Engines) CHECK CHECK FUEL TEST 20 – PULL CHOKE FUEL SHUTOFF FULL OUT GOOD GOOD CHECK FULL OUT SUPPLY VALVE SPARK PULL OUT REPLENISH FUEL TURN SUPPLY...
Section 5 Engine Diagnostic Tests Problem 16 – Engine Starts Hard and Runs Rough (220/410/530cc Non-EFI Engines) TEST 21 – TEST 20 – CHECK CHOKE CHECK FUEL CHECK CHECK GOOD GOOD POSITION AND GOOD GOOD SUPPLY SPARK PLUG SPARK OPERATION ENGINE MISFIRE LOW FUEL APPARENT...
Section 5 Engine Diagnostic Tests Problem 19 – Engine “Hunts” / Erratic Idle (220/410/530cc Non-EFI Engines) *Acceptable running limits for the engine are between 59-62 Hertz. TEST 23 – STILL CHOKE TEST SURGING TEST 24 – CHECK TEST 20 – SURGING VALVE GOOD...
Section 5 Engine Diagnostic Tests Introduction Procedure A – Perform Starter Circuit Voltage Drop Test Perform the Diagnostic Tests in this section in Set a digital multimeter (DMM) to measure DC volt- conjunction with the Diagnostic Flow Charts. Test age. numbers in this chapter correspond to numbered tests in the flow charts.
Section 5 Engine Diagnostic Tests Connect one meter test lead to disconnected Wire 0 from Terminal 2 and connect the other meter test lead to the positive post of the battery, 12 VDC should be measured. If voltage is not measured, repair or replace Wire 13A between the starter contactor and the START-RUN-STOP switch.
Section 5 Engine Diagnostic Tests Checking The Pinion Broken, damaged or weak magnets. Starter drive dirty or binding. Figure 5-7. When starter motor is activated, the pinion gear should move and engage flywheel ring gear. If pinion does not move normally, inspect pinion for binding or sticking.
Section 5 Engine Diagnostic Tests Results Clean and gap or replace sparks plug as necessary. Refer to flow chart. Test 22 – Check Carburetion Procedure Before making a carburetion check, be sure fuel supply tank has fresh, clean gasoline. 002075 Check all shutoff valves are open and fuel flows freely Figure 5-10.
Section 5 Engine Diagnostic Tests Test 23 – Choke Test Procedure If generator is surging, it may be a carburetion problem. A lean condition can cause erratic RPM. Slowly pull choke out to see if surging stops. If it does stop, carburetion should be checked.
Section 5 Engine Diagnostic Tests Test 25 – Check Engine / Cylinder Rotate engine crankshaft until the piston reaches top dead center (TDC). Both valves should be Leak Down Test / Compression Test closed. General Theory Lock flywheel at top dead center. Attach cylinder leak down tester adapter to spark Most engine problems may be classified as one, or a plug hole.
Section 5 Engine Diagnostic Tests Test 26 – Check Ignition Coil If coil passes Step 4 and Step 5 but there is still no spark, replace ignition coil. General Theory NOTE: Before replacing ignition coil, check flywheel magnet. The ignition system used on these engines is a solid- state (breakerless) type.
Section 5 Engine Diagnostic Tests Test 29 – Check / Adjust Governor (208/389/420cc Non-EFI Engine) Rotor operating speed and AC output frequency are proportional. The generator delivers a frequency of 60 Hertz at 3600 Rotor rpm or 62 Hertz at 3720 Rotor rpm. The Voltage Regulator should be adjusted to deliver 120 VAC (line-to-neutral) at a frequency of 60 Hertz or 124 VAC (line-to-neutral at 62 Hertz.
Section 5 Engine Diagnostic Tests Test 30 – Check / Adjust Governor Test 31 – Check Oil Pressure Switch (220/410/530cc Non-EFI Engine) If engine cranks and starts, then shuts down almost immediately, check the following: generator AC frequency output directly proportional to the speed of the rotor.
Section 5 Engine Diagnostic Tests Test 33 – Test Recoil Function d. Connect one test lead to Wire 0 (disconnected from LOP). Connect the other test lead to a clean Procedure frame ground. CONTINUITY should measured. If CONTINUITY is NOT measured Attempt to pull start engine and observe the repair or replace Wire 0 between the LOP and following:...
Section 5 Engine Diagnostic Tests to 14 VDC. If voltage is not present, replace Start Engine and let run for about a minute. charger. If voltage is present, remove battery Measure voltage on battery positive and negative cables from battery. terminals.
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Section 5 Engine Diagnostic Tests If CONTINUITY was measured in step 6, continue testing. If CONTINUITY was not measured, replace switch and test. Set DMM to read AC volts and remove wire 11B from low idle switch. Place one meter lead on wire 11B and the other lead to the ground in control panel.
Major Disassembly Section 6 Introduction Each generator model has a unique method of disassembly. Figure 6-1 is a simplified version of disassembly that does not go into step by step instructions. The figure below represents the basic disassembly and sequence of steps needed to remove the fuel tank, stator, rotor, and the engine.
Electrical Data Section 7 Introduction Go to www.generac.com (http://www.generac.com/service-support/product-support-lookup) for the most current wiring diagrams and electrical schematics. Use model or serial number. Diagnostic Repair Manual...
Electrical Formulas To Find Known Values 1-phase 3-phase E X I E x I x 1.73 x PF Kilowatts (kW) Volts, Current, Power Factor 1000 1000 E x I E x I x 1.73 Volts, Current 1000 1000 kW x 1000 kW x 1000 Amperes kW, Volts, Power Factor...
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