DIAGNOSTIC REPAIR
Contents
1. DIAGNOSTIC REPAIR MANUAL Air Cooled Recreational Vehicle Generators GENERAC rinted in ILS FOREWORD This DIAGNOSTIC REPAIR MANUAL has been prepared especially for the pur pose of familiarizing service personne with the operational analysis troubleshooting testing disassembly and repair of the Series NP45G NP55G and NP65G recreational vehicle generators Keep the Manual in a safe place and refer to it as often as necessary The Manual contains important technical data and should be referred to whenever the need for such Information arises Every effort has been expended to ensure the information in the Manual Is both accurate and current However the manufacturer reserves the right to change alter or otherwise improve his product at any time without prior notice TABLE OF CONTENTS Wiring Diagram and Electrical Schernatic 11 Exploded View of Sheet Metal 26 Exploded View of Base and Pulley 28 Exploded View of Generator and 30 Electrical 32 DEER t IER S 33 Generator Fundamentals Introduction gt Electro Ant indu e a os ai ior coh or cce iatis 2 A Simple a c Generator P DUI dip om ADM UE Introduction to s abi Introdu2. CARBURETOR THROTTLE LEVER ANTI LASH GOVERNOR SHAFT GOVERNOR A GOVERNOR AMP T Voltage Regulator Adjustment AUTION DO NOT adjust the Voltage Regulato until a c output frequency Is correct See ENGINE GOVERNOR ADJUSTMENT B Check that a c frequency is correct as outlined in ENGINE GOVERNOR ADJUSTMENT If frequency is within stated limit 61 63 Hz a c voltage output should be 122 126 volts If voltage is not correct adjust the Voltage Regulator by tuming the VOLTAGE ADJUST potentiometer slowly until a c voltage is within the stated limits regulator is mounted the generator 000000 ELECTRONIC VOLTAGE REGULATOR Automatic Choke Adjustment C Check automatic choke operation and if necessary adjust the choke as follows a Check Choke Operation Crank the engine while ob serving automatic choke operation Initially the Choke Solenoid should energize to close choke for about 0 2 to 0 4 seconds and then de energize for about 2 seconds to open the choke This open close cycle should repeat it self until the engine starts and cranking is terminated b Pre Choke Adjustment With engine cold and Choke Solenoid NOT actuated check that carburetor choke plate Is about 1 8 Inch away from its full open position If necessary to obtain the desired setting use needle nose pliers to bend tlp of BI METAL c Choke Solenoid Adjustment Loosen screws that retain the CHOKE SOLENOID to
3. CONTROL RELAY CR2 CONTROL RELAY CS CHOKE SOLENOID Ft o FUSE 15 emp FP FUEL PUMP QT GROUND TERMINAL HM HOURMETER IGNITION MAGNETO IM2 IGNITION MAGNETO IGNITION SHUTDOWN L1 RUN LIGHT LOW PRESSURE SWITCH Rt RESISTOR 1 ohm 25 watt SC STARTER CONTACTOR SM STARTER MOTOR SW1 START STOP SWITCH SP1 No 1 SPARK PLUG 5 2 No 2 SPARK PLUG TC TERMINAL CONNECTOR WIRE NUT CONNECTION 6 the Choke Solenoid coil and Wire N Battery voltage is delivered through a diode housed the ke Module and to the Wire 14 cir cuit Wire 14 is now ey do to Fuel Pump FP 0 a Choke Heater an Engine lamp on the optional remote panel 3 Control Relay CR2 energizes its normally closed contacts open and the Wire 18 is effectively iso lated from frame ground Ignition can now occur since that circuit is now open to ground 4 With automatic choking and with fuel flow and ignition available the engine will start 5 Engine oil pressure buildup opens the Low Oil Pres sure Switch LOP Circuit Condition Startup and Running C when engine fires and starts the operator willrelease the Start Stop Switch Circuit condition may then be described as follows 1 When a c output from the generator s Battery Charge Winding reaches approximately 9 12 volts a c Control Relay
4. ed CE lt lt LL gt rf gt e gt lt LL 30 Exploded View of Alternator and Panel Drawing No 75231 ITEM REQ D DESCRIPTION 72376 73160 73161 73162 31971 73159 73164 73165 73166 72379 73145 45771 66386 66849 75203 74908 75214 27756 74905 52858 29451 75201 74906 74939 22097 43116 56739 74260 10 53407 74911 48031 D 75213 71908 22473 49813 75202 1 4d m Ber Bet M M m AD od Be wt cA oe A e eh 2 8 o CARRIER Lower Bearing ROTOR ASSY NP45G ROTOR ASSY NP55G ROTOR ASSY NP65G BEARING Ball BEARING STATOR ASSY NP45G STATOR ASSY NP55G STATOR ASSY NP65G CARRIER Upper Bearing STUD Stator NUT Hex M8 1 25 HOLDER Brush SCREW 5 0 80 x 15mm CLAMP Stator Wire SCREW 5 0 80 x 10mm SPACER Cover WASHER Nylon HOUSING Top NUT Flanged Lock M8 1 25 TAPE Foam Rubber 3 feet long BRACKET Panel SCREW M6 1 00 x 20mm PUMP Fuel LOCKWASHER M6 CAPSCREW Hex Head M6 1 00 x 12mm Starter CABLE Starter CABLE Panel Ground ELBOW Pump inlet CLAMP Hose 5 16 FILTER Fuel MOUNT Rubber FLATWASHER M6 NUT Hex M6 HOUSING Panel ITEM 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 PART NO REQ D DESCRIPTION 34616 1
5. Also called a this device permits generator Stator and Rotor winding insulation to be tested for breakdown Use the Hi Pot tester to test resistance between parallel stator windings between isolated windings and the resistance of all windings to ground See also EFFECTS OF DIRT AND MOISTURE ON GENERATORS NOTE An electrical LOAD BANK is recom mended for generator testing and adjustment The Load Bank permits a known electrical load to be ap plied to the generator for the purpose of testing ad justing unit operation under load Rotor Rotational Speed The generator s revolving field on Series NP45G NP55G and NP65G generators is a 2 pole type having a single north and a single south magnetic pote The Rotor is en gine driven through a belt and pulley arrangement Such a 2 pole Rotor must be operated at 3600 rpm to supply an a c frequency output of 60 Hz The and pulley ar rangement provides a speed reduction so that engine speed can be reduced while driving the Rotor at its re quired operating speed The following formulae apply _ ee when determining a c frequency Rotor rpm and number of Rotor poles rpm X No of Rotor Poles Frequency 2x60 2x60 x Frequency RPM No of Rotor Poles 2 x 60 x Frequency Rotor Poles rpm Relationship of Voltage and Frequency Engine governed speed and a c voltage are adjusted with no electrical loads
6. Check for loose mounting bolts and tighten 3 Power Loss a Check for binding or drag in drive train pulleys and belts b Check for defective Rotor bearing c Check for Rotor contact with Stator windings d Check for excessive drive belt tension 4 Noise a Check for a damaged Rotor and or Stator b Check for loose or damaged pulleys and drive belts ADJUSTMENTS General This section is included with other a c generator informa tion because the covered information is so important to proper generator operation and correct a c output The engine governor adjustment may belong in the ENGINE SERVICE MANUAL However that adjustment is so important to correct a c output frequency and voltage that it is Included here Adjustments included in this section Include the following 1 Engine governor adjustment 2 Voltage Regulator adjustment 3 Automatic Choke adjustment NOTE An optional LP gas propane fuel system Is available for use with the NP series generators nstructions for the installation and adjustment o gas conversion kit are included with the kit Engine Governor Adjustment A Also see ROTOR ROTATIONAL SPEED on Page 4 of this Manual The engine govemor is generally ad justed to deliver a generator a c output frequency of 61 62 Hz with no electrical loads connected to the gen erator Following the no load adjustment of engine speed unit operation should be checked with a load appli
7. 17 Problem No 4 Engine Starts Hard Runs Rough 18 Problem No 5 Engine Won t Shut Down 18 Problem No 6 Loss of Generator a c Output 19 Engine Troubleshooting imd Engine onerati XM RYWA 23 Check Engine Ignition e eee 23 Ghack roii eo GI rxA ds 23 Other Problems that Might Affect Engine Operation 23 Adjustments se Engine Governor Adjustments 24 Voltage Regulator Adjustment 24 Automatic Choke 25 GENERATOR FUNDAMENTALS Introduction Ithas long been known that a relationship exists between magnetism and electricity Revolving field a c generators depend on this relationship for their operation The ser vice technician must understand that relationship This section of your DIAGNOSTIC REPAIR MANUAL will familiarize you with the basic fundamentals of generator operation Electro Magnetic Induction Magnetism Creates Electricity When a wire or Coil of wire is moved through a magnetic field an electri cal voltage is created in that wire If the ends of the wire are joined to complete a circuit electrical current will flow in the wire The direction that current flows in the wire depends on the polarity of the magnetic field B Current Fl
8. CONNECTOR 3 4 39271 1 CONNECTOR 90 3 4 73601 1 MODULE ASSY Choke 74074 1 REGULATOR Voltage 22264 5 LOCKWASHER M4 51787 5 SCREW Hex Head M4 0 70 75235 2 SCREW M5 0 80 x 30mm 75234 1 RESISTOR 74095 1 CAPSCREW Hex Head M6 1 00 x 60mm 75210 A 1 BLOCK Terminal 49226 2 LOCKWASHER M5 65795 1 RECTIFIER Battery Charge 75205 1 RELAY 12 volts a c 75204 1 RELAY 12 volts d c 75200 1 PANEL Control 75208 1 SWITCH Start Stop 32300 1 HOLDER Fuse 22676 1 FUSE 15 amp 53650 1 CONNECTOR 75244 1 CABLE ASSY Remote 75471 1 BREAKER Circuit 30 amp 75470 1 BREAKER Circuit 20 amp 47662 AW 1 HOSE 5 16 ID x 4 1 2 73513 4 SCREW No 10 32 x 1 2 57345 2 LUG 63036 2 SCREW 8 18 x 1 4 33136 4 SCREW Hex Head Machine No 6 32 x 5 8 22155 4 LOCKWASHER No 6 22985 4 FLATWASHER No 6 22188 4 NUT Hex No 6 32 51715 5 NUT Hex M4 0 70 25433 1 LUG Ground 56893 1 SCREW Crimptite No 10 24 36900 4 SCREW Pan Head Machine No 6 32 x 1 4 73129 1 DECAL Control Panel Used on NP65G Series Used on NP45G amp NP55G Series ELECTRICAL FORMULAS Alternating Current DESIRED DATA 1 PHASE PHASE Power F 1 73 x Volts x Amps x Power Factor 1009 1000 KVA Volts x Amps 1 73xVoltsxAmps 0 1000 100 Horsepower Volts x Amps x 100 x P F 1 73 x Volts x Amps x 100 x 746 x Efficiency 746 x Efficiency Amperes H P 746 x Efficiency x 746 x Efficiency _
9. DIAGRAM amp ELECTRICA SCHEMATIC on Page 11 Two different types of Co roi Relay CR1 are used on the NP sertes generators identified in the Wiring Diagram as CRT and Al ernate CR1 Also see Figures 4 and 5 Test Procedure See Figure 4 or 5 Test the Relay as fol lows 1 Connect the positive test lead of a d c voltmeter to CR1 terminal 12 Wire 15 terminal connect the negative test lead to a clean frame ground Meter should indi cate battery voltage If alternate CR1 Is installed connect meter positive test lead to Relay terminal 9 Wire 15 terminal Test Results A Battery voltage is indicated Continue test B Battery voltage is NOT indicated Repeat Step 1 Also check Wire 15 between Relay CR1 and Fuse F1 for open or disconnected condition Wire 13 between Fuse F 1 and Starter Contactor SC for open and positive battery cab e to Starter Contactor SC 2 Connect the positive test lead of a 4 voltmeter to CR1 terminal 2 Wire 56 terminal negative test lead to frame ground If alternate CR1 is Installed connect meter positive test lead to Relay terminal 3 Wire 56 terminal Battery voltage should be indicated Test Results A Battery voltage NOT Indicated Replace Control Relay CR1 B Battery voltage was indicated Repeat Steps 1 through 5 Refer to WIRING DIAGRAM Page 11 and test wires for open or shorted condition 14 Figure 4 Control Relay CR1 P
10. Top SCREW Crimptite No 10 32 x 3 8 MODULE Shorting SCROLL Flywheel COVER Base 82 SCREW Taptite M5 x 10mm WRAPPER No 2 Cylinder COVER Valley WRAPPER No 1 Cylindert WRAPPER Barrel CAPSCREW Hex Head 6 1 00 x 10mm LOCKWASHER M6 COVER Base No 1 Cytinder CAPSCREW Hex Head M8 1 25 x 10mm LOCKWASHER M8 SCREW Taptite 3 8 16 x 1 4 WIRE ASSY No 16 COVER Starter WRAPPER Crankcase BUSHING Snap GROMMET Rubber GROMMET Rubber O RING PROBE Oil Makeup ss RETAINER Oil Makeup Probe WASHER Shakeproof M6 SCREW Socket Head M6 1 00 x 8mm CLAMP Hose HOSE 5 16 ID BRACKET Oil Makeup Pump CAPSCREW Hex Head M8 1 25 x 16mm PUMP Cil Makeup WIRE ASSY Ground 5 5 tong WIRE ASSY Ground 15 fon CLAMP Hose TAPE Foam BOOT Spark Plug A Drawing No 75218 EXPLODED VIEW OF BASE amp PULLEY Exploded View of Base 8 Pulleys Drawing No 75218 O ONO BOR O ot BON 15 16 17 18 19 20 21 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 43 ART REQ D 72372 72382 38353 25017 22237 22241 72391 73147 45771 52858 51730 29459 75215 73146 75209 73174 67897 55173 72383 56892 75224 A 75224 B 75224 73106 73106 73106 75216 49451 42633 72381 73118 74906 74908 72375 73185 22097 74909 75242 74910 73156 49099 48031 E 47662 U 47662 BG 50190 7
11. Volts x 100 x P F 1 73 x Volts x 100 x P F Amperes Kilowatts 1000 Kilowatts x 1000 Volts x P F 1 73 x Volts x P F wam 2x60 2 x 60 x Frequency 2 x 60 x Frequency No of Rotor Poles RPM No of Rotor Poles No of Rotor Poles Generator output or load input When Horsepower is known When Kilowatts Is known When is known Engine output 32 Series NP45G Serles NP65G Model 9009 0 Model 9011 0 Rated Maximum 4500 watts Rated Maximum 6500 watts Rated a c 120 volts Rated a c Voltage s 120 volts Rated Maximum Current Rated Maximum Current At 120 volts 37 5 amps At 120 volts 54 2 amps At 240 volts 18 75 amps At 240 volls i reete 27 1 amps Rated Frequency 60 Hz EPROM No of Rotor Poles 2 No of Rotor 2 Govemed Rotor Speed at No Load 3720 rpm Govemed Rotor Speed at No L
12. applied to the generator no load That is the a c voltage is set at a fixed ratio to a c frequency Recommended frequency and voltage set tings are as follows 60 5 to 63 5 Hz 121 to 127 volts Set Frequency to Set Voltage to Line to Neutral Voltage Generator a c Connection System D Series NP45G NP55G and NP65G RV generators are equipped with dual Stator a c power windings These windings may be connected in parallel to provide a 120 volts a c output as shown Note that customer loads of up to 30 a c amperes may be connected across Wires T1 red and T2 white loads up to 20 a c amperes across wires T2 white and T3 black E Thegenerator s a coutputleads may be reconnected In series to supply a dual voltage 120 and or 240 volts output When this Is done connect 240 volts a c loads across T1 red and T3 black 120 volts across T1 red and T2 white or T3 black and T2 white T2 is the neutral wire Effects of Engine Power The generator engine must develop sufficient power to operato the generator under varying electrica loads Tho greater the wattage amperage demands of connected electrical loads the greater the engine power needs As a general rule approximately 2 engine horsepower is needed for each 1000 watts 1 0 kW of generator power output W the generator s wattage amperage capacity is ex ceeded engine power may not be adequate to handle the Increased load The result will be a d
13. as required 18 e Step 4 Test Automatic Choke Test Procedure Refer to Steps 7 and 8 of Problem No 2 for automatic choke system test procedures See AD JUSTMENTS section as well Test Results A Choke tests GOOD Repeat Steps 1 thru 3 B Choke tests BAD Repair adjust or replace defective component s as necessary Problem No 5 Engine Won t Shut Down Step 1 Check Start Stop Switch Test Procedure Test the Start Stop Switch Fig 13 as follows 1 Check Wire 0 between Start Stop Switch and ground terminal GT for open condition Ground connection must be good before proceeding 2 Disconnect Wires 17 and 18 from Switch terminals to prevent interaction 3 Set VOM Rx1 scale and zero the meter 4 Connect one meter probe to the Wire 17 terminal and connect the remaining test probe to Wire 0 ground terminal Meter should indicate Infinity 5 Actuate the Switch to Its START position should read continutity 6 Release Switch Meter should indicate Infinity 7 Set Switch to STOP Meter should indicate infinity 8 Connect one meter probe to the Wire 18 terminal of Switch and connect the remaining test probe to Wire 0 ground terminal With Switch at START VOM should indicate infinity Hold Switch at STOP and meter should read continuity Test Results A Start Stop Switch SW1 checks GOOD Go to Step 2 B Start Stop Switch SW1 checks BAD Replace Switch Figure 13 StarvS
14. brush C Engine cranks and normal voltage indicated Go to Step 7 Step 7 Check Stator Excitation Windings Test Procedure Disconnect Stator Excitation Winding output leads 2 and 6 Fig 17 from the Electronic Voltage Regulator Set a VOM to its Rx1 scale and zero the meter Connect VOM test leads across terminal ends of Wires 2 and 6 The VOM needle should swing upscale and Indicate the following resistance NP45G Units 2 2 ohms NP55G Units 1 8 ohms NP65G Units 1 6 ohms All resistance values are plus or minus 10 Now set the VOM to its Rx 10 000 scale and again zero the meter Connect one VOM test lead to Wire 2 and the remaining test lead to a clean frame ground You should not detect any upscale movement infinity of the VOM needle Figure 17 Stator Excitation Winding Test Points ELECTRONIC VOLTAGE REGULATOR O Test Results A Excitation windings check GOOD Go to Step 8 B Excitation windings check BAD Replace Stator As sembly NOTE Also see INSULATION RESISTANCE TEST on Page 9 Typically In the above test a low resi ance indicates a shorted condition a high resis tance indicates an open condition Test 8 Check Stator Power Warnings Test Procedure Test the Stator Fig 18 a c power windings as follows 1 Disconnect a c power winding output leads 11 and 22 from the Electronic Voltage Regulator 2 Disconnect a c power winding output lead 33 from Circuit
15. flow toward carburetor With new fil ter installed recheck fuel flow as outlined in Step 3 Test Results A Fuel flow is normal STOP tests B Fuel flow stiil inadequate Go to Step 5 Figure 6 Engine Fuel System AIR CLEANER CARBURETOR BEHIND AIR INSTALLER S CONNECTION POINT Step 5 Check Fuel Pump Gasoline System Only Test Procedure Locate the 4 tab terminal connector to which Wires 14 connects Locate Wire 14 from Fuel Pump on the termina connector Connect the positive test lead of a d c voitmeter to the Fuel Pump s Wire 14 ter minal connect negative test lead to a clean frame ground Crank engine the voltmeter should indicate bat tery voltage and the Fuel Pump should operate Test Results A Battery voltage is indicated and Fuel Pump operates but still no start Go to Step 6 B No battery voltage indicated and Fuel Pump does not operate Go to Step 7 15 Step 6 Check Engine Ignition System Test Procedure Refer to section In this Manual entitled ENGINE TROUBLESHOOTING Also refer to the EN GINE SERVICE MANUAL if necessary Test Results A Ignition System checks GOOD Go to Step 7 B Ignition System checks BAD Repair or replace defec tive component s mas necessary Step 7 Test Choke Module NOTE The following procedure will test the Wire 14 diode the field boost diode and the field boost resistor To test these components it Is recom mended that a Volt O
16. scale compare the read ings obtained with the following SPECIFIC GRAVITY PERCENT OF CHARGE Step 3 Check Starter Contactor SC Test Procedure Starter Contactor operation may be tested as follows 1 See Figure 1 Connect the positive test lead of a 0 c voltmeter to the Wire 56 terminal of the Starter Contac tor Connect the meter negative test lead to a clean frame ground The voltmeter should indicate battery age 12 volts d c Test Results A Battery voltage NOT indicated Go to Step 6 B Battery voltage was indicated Continue test 2 Connect the positive test lead of a d c voltmeter to the Wire 16 terminal stud of the Starter Contactor con nect negative test lead to a clean frame ground Zero volts should be indicated 3 With d c voltmeter stili connected to the Wire 16 ter minal stud and frame ground disconnect Wire 17 from its terminal stud on Starter Contactor Connect ajumper wire from the Wire 17 terminal stud on Starter Contactor to a clean frame ground The d c voltmeter should Indicate battery voltage and engine should crank Test Results A Battery voltage GOOD and engine cranks but will not crank with Start Stop Switch Go to Step 5 B Battery voltage GOOD engine does NOT crank Go 1 260 100 to Step 4 1 230 75 1 200 50 C Zero battery voltage with jumper wire connected and 1 170 25 engine does not crank Replace Starter Contactor SC necessary use an a
17. the Electronic Voltage Regulator and the Stator as outlined in Step 8 Test Results A Wires 11 and or 22 indicate open or shorted condition Repair or replace wires as necessary B Wires 11 and 22 check GOOD Go to Step 11 Step 11 Check Adjust Voitage Regulator Test Procedure Refer to ADJUSTMENTS section With correct a c frequency indicated try adjusting the Voltage Regulator Frequency and voltage must both be within the specified limits Test Results A Frequency GOOD cannot adjust in the correct voit age Replace the Voltage Regulator adjust and test unit B Frequency and Voltage both GOOD STOP tests o readily a ENGINE TROUBLESHOOTING General Most problems pertinent to engine operation may be clas sified as one or a combination of the following 1 Will not start 2 Hard Starting 3 Lack of power 4 Vibration 5 Overheating 6 High oll consumption When the cause of a problem is not readily apparent per form a check of the engine s Compression Ignition and Carburetion systems Checkout of these systems if per formed in a systematic manner can usually be done in a few minutes it is the fastest and surest method of finding the cause of a problem What appears to be an engine problem may sometimes be caused by the system that the engine ts driving For example overloading the generator exceeding its wat tage capacity can cause the same indications as an un ered eng
18. 4 Check Load Voltage and Frequency Step 5 Check Adjust Engine Governor Step 6 Check Field Boost Circuit Step 7 Check Stator Excitation Windings Step 8 Check Stator a c Power Windings Step 9 Check Rotor Field Circuit Step 10 Check Voltage Regulator Sensing Step 11 Check Adjust Voltage Regulator ee a Zi a ra ce TROUBLESHOOTING GUIDELINES Problem No 1 Engine Won t Crank Step 1 Check 15 amp Fuse F1 Test Procedure Remove Fuse F1 from generator panel and inspect fuse element necessary use a Volt Ohm Milliammeter VOM to check fuse for continuity Test Results A Fuse F1 checks GOOD Go to Step 2 B Fuse F1 is open Replace Fuse F1 If engine cranks normally STOP Step 2 Check Battery Test Proceduro Perform the following checks tests on the generator battery 1 Inspect battery terminals posts and cables Cable clamps and connections must be clean and tight Clean and or tighten cable clamps and connections as neces sary Replace any defective cables 2 Use an automotive type battery hydrometer to test bat tery STATE OF CHARGE Follow the hydrometer manufacturer s instructions carefully Write down the specific gravity of the electrolyte fluid in each battery cell Write down the specific gravity reading of each cell as the reading is taken Return the electrolyte fluid to the celi from which it was removed If the hydrometer used does nothave a percentage of charge
19. 4913 73181 1 1 4 4 A DESCRIPTION BASE Mounting PAN Collector MOUNT Rubber CAPSCREW Hex Head 3 8 16 x 1 2 LOCKWASHER M10 NUT Hex 3 8 16 SKID Rubber Mount BOLT Safety NUT Hex M8 1 25 NUT Flanged Lock M8 1 25 CAPSCREW Hex Head M8 1 25 x 60mm SPRING Bett Tensioner WASHER Spring Center SLIDE Nyton SUPPORT Slide MANIFOLD Exhaust GASKET Exhaust Manifold CAPSCREW Hex Head M8 1 25 x 20mm Grade 10 9 GASKET Collector Pan SCREW Crimptite No 10 24 PULLEY Engine Fan NP45G PULLEY Engine Fan NP55Q PULLEY Engine Fan NP65G PULLEY Generator Fan NP45G PULLEY Fan NP55G Only PULLEY Fan NP65G Only BELT Poly V 4L 40 WASHER Pulley Retainer CAPSCREW Socket Head 3 8 24 1 Grade 5 GUIDE Blower Housing CAPSCREW Hex Head 3 8 24 x 2 1 2 SCREW Taptite 6 1 00 x 20 SCREW Taptite M5 0 80 x 10 HOUSING Blower SPACER Blower Housing LOCKWASHER M6 CAPSCREW Hex Head 5 0 80 x 70mm SPRING Generator Set Mount TANK Makeup CAP Makeup Tank ELBOW 90 Barbed CLAMP Hose 3 8 HOSE 3 8 6 long HOSE 3 8 ID x 25 tong WASHER Tank Retainer CAPSCREW Hex Head M6 1 00 x 110mm TUBE Oli Fill and Drain ITEM REQ D_ DESCRIPTION 44 45 46 47 48 49 SISAL 258085848898266528 74958 67871 67866 73135 73138
20. 74936 43790 47662 BC 35461 69811 65852 52857 73179 70185 60108 74948 74950 74951 73134 38750 74949 69547 46453 29289 35472 75281 43181 43182 22473 75237 61274 75474 73176 74907 75226 56892 75229 75227 43116 22473 22097 72384 B 74808 74906 76267 W a A A A e mh nh o o ts ots gt A u ot ot mh oh nmm m mh HR 8 DIPSTICK ASSY O RING Cap O RING Drain PIPE Drain Adapter ELBOW 90 3 8 NIPPLE 3 8 NPT x 2 1 4 ELBOW 3 8 NPT x 3 8 HOSE 3 8 x 10 1 2 FITTING Barbed 1 4 NPT x 3 8 CAP Hex 1 4 NPT CLIP Hose Retainer NUT Flanged Lock M6 1 00 SUPPORT Oil Filter FILTER Oll FRAM PH3614 SWITCH Oll Pressure FITTINQ 5 16 TUBE Outer Oil TUBE Inner ADAPTER Pad CAPSCREW Hex Head M6 1 00 x 30mm FITTING Barbed 90 5 16 GASKET oil Pad LUG Grounding TAPE Foam 1 16 thick x 8 ft CLAMP SWITCH High Temperature SCREW Pan Head 0 50 LOCKWASHER M3 FLATWASHER M amp WASHER Spring Retainer SWITCH High Water Temp Vynyt 17D x 42L x 2H ELBOW Exhaust CLAMP Exhaust 1 1 8 COVER SCREW Crimptite No 10 32 GASKET Stide Pan SLIDE PAN CAPSCREW Hex Head M6 1 00 x 12mm FLATWASHER 6 LOCKWASHER M6 COVER Exhaust Outlet SCREW Taptite M5 x 10mm SCREW Taptite M6 1 00 x 20 SPACER Plastic Drawing 75231
21. Breaker CB1 3 At the wire nut junction of a c output leads 22 and 44 separate the two wires 4 Set a VOM to its Rx1 scale and zero the meter Connect VOM test leads across wire ends of Wires 11 and 22 and note the resistance reading in ohms Resis tance should be as follows plus or minus 10 NP45G Units 0 4 ohms NP55G Units 0 3 ohms NP65G Units 0 2 ohms 5 Connect VOM test leads across wire ends of Wires 33 and 44 Again note the resistance Resistance should be the same as Item 4 above 6 Set VOM to its 10 000 scale and zero the meter Connect one VOM test lead to Wire 11 and the second test lead to frame ground The VOM needie should not move upscale infinity Now connect one test lead to Wire 33 and the second lead to frame ground Meter should indicate infinity Test Results A Power Windings check GOOD Go to Step 9 B Power Windings check BAD Replace Stator Assemb ly Figure 18 Stator a c Power Windings Test Points Step 9 Check Rotor Field Circult Test Procedure Use a VOM to test Wire 4 between Electronic Voltage Regulator and Choke Module for open or shorted condition Wire 4 between Choke Module and Brushes was previously tested in Step 6 Then inspect brushes and slip rings and test Rotor as foliows 1 Remove Wires 4 and 0 from Brushes then remove Brush Holder Inspect Brushes and Brush Holder Repiace if cracked damaged wom excessively etc Inspect Slip Rin
22. CR1 energizes and its normally open contacts close to deliver battery voltage to the Wire 14 circuit Fuel Pump and Choke Heater actions continue 2 The Starter Contactor SC and Control Relay 2 circuits to ground are opened G DIN ERY CHARGE AAAS AC 2 i Sait La 3 Starter Contactor SC de energizes and Its contacts open to effect the following Motor SM de enerizes and cranking ends b Carburetor choking terminates c Field Boost ends d Power to the Wire 14 circult through the Choke Module ends 4 Control Relay CR2 de energizes and its normally closed contacts close However the ignition circuit to ground is held open Low Pressure Switch LOP action and engine ignition continues 5 Stator Battery Charge Winding rectified output 15 delivered to the generator battery Circuit Condition Normal Shutdown D Closure of the Start Stop Switch SW1 to its STOP position grounds the engine ignition circuit ignition ter minates and the engine shuts down As engine speed decreases Low Pressure Switch LOP closure main tains the ignition ground condition a INSULATION RESISTANCE TESTS General Refer to EFFECTS OF DIRT AND MOISTURE ON RV GENERATORS Page 5 The resistance of rotor and stator windings should be tested periodically using a HI Pot resistance tester CAUTION When using the HI Pot Insulat
23. NGS CARBON BRUSHES POWER WINDING Generator Block Diagram E The Rotor spinning field is driven by the engine through a belt and pulley arrangement to maintain a fixed operating speed The Rotor s magnetic field cuts across a a Stator a c power winding b a Stator excitation winding and c a Stator battery charge winding to induce a voltage into those windings 1 Stator Battery Charge Winding Rectified direct current output from this winding is delivered to the gen erators 12 volts battery to maintain battery state of charge Voltage 2 Stator a c Power Winding The a c output from this winding is used to supply electrical power to connected electrical loads 3 Excitation Winding Output from this winding is delivered to an Electronic Voltage Regulator where It is rectified and based on a c power winding sensing sig nals regulated The regulated rectified current flows through the brushes and slip rings and into the Rotor windings Because the current flow is regulated the Rotors magnetic field strength is regulated In turn be cause the field strength ts regulated the voltage Induced into the Stator windings is regulated Regulator 12 VOLTS BATTERY Stator Customer Load Connections Stator Excitation Winding Stator a c Power Winding Stator a c Power Winding Battery Charge Winding BATTERY CHARGE DIODE Revolving Fleld Rotor 21 Silip Rings INTROD
24. Switch is released Test Results A Oil level is LOW Add oli as required don t forget Makeup Tank B level is GOOD Go to Step 2 NOTE You may wish to check engine ol pressure See ENGINE SERVICE MANUAL for oll pressure check procedures and specifications Step 2 Check Pressure Switch Test Procedure Set a VOM to its Rx1 scale and zero the meter Disconnect Wire 85 from the Switch terminal then test the Low Oll Pressure Switch Fig 10 as follows 1 Connect one VOM test lead to the switch terminal the remaining test lead to a clean frame ground Meter should indicate continuity 2 Crank engine The VOM needle should drop all the way downscale infinity as oil pressure increases 3 If the engine starts and runs hold terminal end of Wire 85 into firm contact with a dean frame ground Engine should shut down Test Results A Oil Pressure Switch checks GOOD Go to Step 3 Step 3 Check Temperature Switch Test Procedure Set a VOM to its Rx1 scale and zero the meter Disconnect Wire 85 from the Switch terminal then test the Temperature Switch Fig 10 as follows 1 Connect one VOM test lead to the switch terminal the remaining test lead to a clean frame ground Meter should indicate continuity 2 If the engine starts and runs hold terminal end of Wire 85 into firm contact with a clean frame ground Engine should shut down Test Results A Tempe
25. TING GUIDELINES Before making a carburetion check make sure a an adequate supply of fuel Is available b all fuel shutoff valve s are open and c fuel flow 15 adequate Try adjusting the en gine carburetor Check automatic choke operation and make sure the choke is adjusted properly If engine will not start remove and inspect the Spark Plug If Spark Plug is WET look for 1 Overchoking 2 Excessively rich fuel mixture 3 Water in fuel 4 Intake valve stuck open If Spark Plug is DRY look for 1 Leaking carburetor gasket s 2 Dirty or gummy carburetor 3 Intake valve stuck closed 4 Inoperative fuel pump A simple check to determine It fuel is reaching the com bustion chamber Is to remove the spark plugs and pour a small amount of gasoline through the Spark Plug hole install and tighten Spark Plugs Crank engine If engine flres a few times and then stops look for the same con ditions as a dry plug Other Problems that Might Affect Engine Operation 1 Hard Starting or Will Not Start a Loose drive belts or pulleys these can cause a backlash effect that will counteract engine cranking effort b Starting under load attempting to start with heavy electrical loads applied can often cause problems c Shorted condition in the generator or in connected electrical loads can impose a heavy load on the en gine thus preventing start 2 Vibration a Check for defective or damaged pulleys drive belts or Rotor b
26. UCTION TROUBLESHOOTING introduction A typical generator set does not have a large number of parts However the parts are expensive For that reason aparts replacement method of troubleshooting is not cost effective basic understanding of generators is essential to good troubleshooting i e why they behave or don t behave as they should This section will Introduce the technician to some of the fundamentals of troubleshooting DANGER Recreational vehicle generators produce attempt to troubleshoot test repalr or service a ge erator Tools and Test Equipment The generator service technician should have a well stocked tool box having a good selection of common hand tools Such a tool box should contain wrenches in both metric and english sizes recommended is a good nut driver set Volt Ohm Milllammeter An accurate volt chm mil tiammeter VOM is essential for the troubleshooting and testing of generators Simply having a VOM is not enough The technician must understand electricity must be familiar with electrical circuits must be able to read wiring diagrams electrical schematics and must know how tio use the VOM B Frequency Meter This test device permits the gen erator s a c output frequency in HERTZ or CYCLES PER SECOND to be read Measurement of frequency is re quired for precise adjustment of engine generator speed Also see ROTOR ROTATIONAL SPEED C insulation Resistance Tester
27. cessary also refer to the EN GINE SERVICE MANUAL Test Results A Engine Checks GOOD Go to Step 10 B Engine checks BAD Repair replace engine as neces sary Step 10 Test Relay CR2 Test Procedure See Figure 9 Disconnect Wire 18 from Relay Terminal 2 and Wire 85 from Terminal 4 to prevent interaction Set a VOM to its Rx1 scale and zero the meter Then connect the VOM test leads across Relay Terminals 2 and 4 the meter needle should swing ups cale continuity Hold Start Stop Switch at START to crank engine the VOM needle should drop all the way downscale infinity Test Results A Control Relay CR2 checks GOOD Repeat Steps 1 through 9 Control Relay CR2 checks BAD Replace Relay CR2 Figure 9 Control Relay CR2 Problem No 3 Engine Cranks and Starts Shuts Down When Start Stop Switch is Released Step 1 Check Engine OII Level Test Procedure Check engine oll level as outlined in Owner s Manual If oil level is low sufficient pressure to open the Low Oil Pressure Switch contacts will not be developed With Start Stop Switch at START Control Relay CR2 action will open the engine ignition circuit to ground However as soon as the Start Stop Switch Is released CR2 contacts will close and closure of the Low Oil Pressure Switch contacts will close the ignition circuit to ground and ignition will terminate The resuit will be an engine shutdown as soon as the Start Stop
28. clean and dry the stator Then repeat the breakdown test If Breakdown lamp iliuminates after drying replace the Stator Assemb ly Testing Rotor insulation for Breakdown D Remove generator cover to gain access to the Rotor slip rings and brushes E Remove all wires that connect to the Brushes Then test Rotor insulation as follows 1 Connect tester RED test lead to the positive Rotor slip ring nearest the Rotor bearing 2 Connect BLACK test lead to a clean frame ground 3 Turn tester switch OFF 4 Plug tester into a 120 volts wall socket 5 Set Voltage Selector Switch on tester to 500 volts 6 Tum tester switch ON and check that Pilot Light is ON 7 Set Voltage Selector Switch to 1250 volts and observe the tester breakdown lamp Then turn tester switch OFF RESULTS tester breakdown lamp Illumiates during the 1 second test drying of the generator may be necessary After drying repeat the Hi Pot test If Rotor windings fall the second test after drying replace the Rotor assembly Cleaning the Generator Removed caked on or greasy dirt with a soft brush or a clean damp cloth A vacuum system may be used to pick up loosened dirt Loose dust and dirt may also be removed using low pressure dried air 25 psi maximum p iit CAUTION Do NOT a forceful spray of water to lean generator Some of the water will be retained on generator windings and will caus
29. ction C Tools and Test i Etpe ERROR E eH M PAPER GI 4 Rotor Rotational 4 Relationship of Voltage and Frequency 5 Generator a c Connection System 5 Effects of Engine Power eee 5 Effects of Dirt and Moisture on RV Generators 5 Operational Analysis of D C Control System ue uc ror Step patriis S 6 Circuit Condition Engine Shut Down 6 Circuit Condition Engine Cranking 6 Circuit Condition Startup and Running 7 Circuit Condition Normal Shutdown 8 Insulation Resistance Tests s OE YOGA 9 9 Testing Stator Insulation sess 9 Testing Rotor Insulation for Breakdown 10 Cleaning the 10 Drying ihe GMOT eiae reor O Troubleshooting the RV Generator GOW ATZ 12 Problem 1 Engine Won t Crank 13 Problem No 2 Engine Cranks Won t Start 15 Problem No 3 Engine Cranks and Starts Shuts Down When Start Stop Switch Is Released
30. d the TEST RESULTS Some test results may instruct you to skip certain steps and proceed to a new step number Problem No 1 Engine Won t Crank Step 1 Check 15 amp Fuse F1 Step 2 Check Battery Step 3 Check Starter Contactor SC Step 4 Check Starter Motor SM Step 5 Check Start Stop Switch SW1 Step 6 Check Control Relay CR1 Problem No 2 Engine Cranks Won t Start Step 1 Check Fuel Quantity Step 2 Check Fuel Shutoff Valves Step 3 Check Fuel Flow Step 4 Check Fuel Filter Step 5 Check Fuel Pump Step 6 Check Engine Ignition System Step 7 Test Choke Module Step 8 Check Automatic Choke Operation Step 9 Check Engine Compression Condition Step 10 Test Control Relay CR2 Problem No 3 Engine Cranks and Starts Shuts Down When Start Stop Switch is Released Step 1 Check Engine Oil Level Step 2 Check Pressure Switch Step 3 Check Control Relay CR1 Step 4 Check Stator Battery Charge Windings Step 5 Check Resistor R1 Problem No 4 Engine Starts Hard Runs Rough Step 1 Check Engine Ignition System Step 2 Check Carburetion Step 3 Check Engine Compression Step 4 Test Automatic Choke Problem No 5 Engine Won t Shut Down Step 1 Check Start Stop Switch Step 2 Check Wire 18 amp 0 Step 3 Check Engine Ignition System 1 S D Problem No 6 Loss of Generator a c Out put Step 1 Check Circuit Breakers CB1 CB2 Step 2 Check Vehicle Wiring Step 3 Check a c Voltage and Frequency Step
31. e serious Drying the Generator 1 Open the main circult breaker or main line switch NO ELECTRICAL LOADS MUST BE CONNECTED TO GENERATOR WHILE DRYING 2 Remove the generator cover see illustration B on previous page 3 Disconnect Wire 4 from the Electronic Voltage Regulator 4 Provide an external source to blow warrn dry air through the generator Do NOT exceed 185 F 85 C 5 Start the engine let It run for 2 to 3 hours 6 Stop the engine and retest Stator and Rotor windings 10 lt i andit i uu e 227858 8 T TEN E TROUBLESHOOTING THE RV GENERATOR Introduction The service technician can use this troubleshooting guide to determine the cause of existing problems Six common problems are covered in this section Problems are not arranged in any particular sequence The first step in troubleshooting is to identify your par ticular problem When you have identified your problem locate that problem in the troubleshooting guide on this page When working your way through the step by step procedure for that problem start at Step 1 and follow through the step by step procedure Each step Is ar ranged in a definite sequence from the more prob able easiest to check to the less probable more complex to check When the cause of the problem is found and corrected stop the test Follow the step by step procedures carefully After com pleting each test rea
32. ecrease In engine rpm a corresponding decrease in generator output voltage and frequency and intemal generator overheating A badly wom engine one that has lost compression or one with defective fuel ignition or air Intake system may not be able to handle loads within the generator s rated capacity Problems with generator a c output are often caused by an engine problem NOTE A shorted condition in one or more con Effects of Dirt and Moisture on RV Generators moisture is permitted to remain in contact with gener ator windings some of that molsture may be retained in cracks and volds of the winding insulation This will cause a reduced insulation resistance However prolonged exposure to moisture resistance of stator and rotor winding insulation Dirt can make the problem worse since it tends to hold moisture into contact with windings Salt as from sea air also makes the problem worse since salt will absorb moisture from the air When salt and moisture combine they form a good electrical conductor Because of the detrimental effects of dirt and moisture the generator should be kept as clean and as dry as possible Stator and rotor windings should be tested periodically using an insulation resistance tester Hi Pot megohmmeter If insulation resistance is excessively low drying may be required to remove moisture After Grying a second test of Insulation resistance Is still low after drying replac
33. ed Adjust the engine governor as follows 1 Visually inspect ANTI LASH SPRING make sure it is not broken or disengaged Spring ends must be hooked into GOVERNOR LEVER at bottom end and into car buretor THROTTLE LEVER at top 2 Loosen GOVERNOR CLAMP NUT 3 Push spring end of GOVERNOR LEVER all the way up to wide open throttle position While holding the LEVER down insert a screwdriver into slotted end of GOVERNOR SHAFT and rotate SHAFT fully counterclockwise Then tighten the GOVERNOR CLAMP NUT to 100 inch pounds of torque AUTION Governor shaft MUST be rotated full ounterclockwise with throttle wide open or full governor travel will not be reached Governor clamp nut must be tight full governor travel may be lost due to vibration 4 Connect an accurate a c frequency meter and voltmeter across generator a c output leads T2 white and black for Series NP45G NP55G or across leads T1 red and T2 white for Series NP65G See Step 3 under Problem No 6 on Page 19 Check A C VOLTAGE AND FREQUENCY 5 Start the engine Let it stabilize and warm up for a few minutes with NO ELECTRICAL LOADS APPLIED TO GENERATOR 24 6 Check a c frequency it should be 61 63 Hz If not tum FUN ADJUSTER NUT until frequency is correct 7 With governed speed at 61 63 Hz no load check voltage reading Voltage should be 122 126 volts If not adjustment of the Voltage Regulator is required IDLE STOP SCREW
34. ement of defective windings may be necessary 81 30 emp circu wether 82 Wo wesie 042690 20 amo breaker 45 50 OPERATIONAL ANALYSIS OF D C CONTROL SYSTEM Introduction This section of your Manual is intended to familiarize the reader with how the RV generator s d c control system functions The d c control system provides the means to obtain engine cranking engine ignition and fuel flow car buretor choking field boost and battery charging If problems with any of these functions are encountered thetechnician musthave a working knowledge of how the System operates Circuit Condition Engine Shut Down With engine stopped the circuit condition may be described as follows 1 Battery voltage is available to the normally open Starter Contactor SC contacts The contacts are open and the circult is incomplete 2 Battery voltage is available through a 15 amp Fuse F1 and to the normally open contacts of Control Relay CR1 These contacts are open and the circuit is incomplete 3 Battery voltagte is available through Fuse F1 through the normally closed contacts of Control Relay CH1 through the Starter Contactor SC coll and to the Start Stop Switch SW1 However the Switch contacts are open and the circuit is incomplete 4 Battery voltage is available through Fuse F1 through the Contro Relay CR2 actuating coil and to the Start Stop Switch SW1 Howeve
35. ency are correct STOP tests B Voltage Frequency still incorrect Go to Step 6 Step 6 Check Field Boost Circuit NOTE Some residual magnetism Is normali asidual magnetism is also fost Test Procedure Test the Field Boost circult as follows Figure 15 1 Disconnect Wires 4 from Pin 2 of the Choke Module Figure 15 Choke Module 2 Connect the positive test lead of the a d c voltmeter to Pin 2 of Choke Module CM Connect negative test lead to a clean frame ground 3 Crank the engine The voltmeter should indicate about 7 10 volts d c with engine cranking Test Results A Engine won t crank Go to Problem No 1 Engine cranks but d c voltage is indicated Replace Choke Module CM and recheck for proper voltage If voltage is good STOP test Engine cranks and normal voltage is indicated Con tinue test 4 Gain access to Brushes and Slip Rings Fig 16 5 Connect the positive lead of a d c voltmeter to the terminal of the positive brush RED lead connection Connect voltmeter test lead to a clean frame ground 6 Crank engine The voltmeter should indicate about 7 10 volts d c with engine cranking Figure 16 Brushes and Slip Rings Test Results A Engine won t crank Go to Problem No 1 B Engine cranks and no d c voltage indicated but volt age was indicated in 3 of test Repair or replace Wire 4 between Choke Module CM and the positive
36. ge drop across the resis tor NOTE The Fleld Boost Resistor Is rated 47 ohms at 2 watts plus or minus 10 The Fleld Boost diode Is rated 1 amp at 600 volts 3 The Choke Module circuit includes a metal oxide Varis tor rated 22 volts 0 6 0 8 Joule There Is no good method of testing a Varistor in the field Typically when a Varis tor fails it will overheat and melt Inspect the Choke Module if evidence of overheating and melting is ob served replace the Choke Module Test Results A Choke Module tests are GOOD Go to Step 8 Choke Moudle tests BAD Replace Choke Module 16 Figure 7 Choke Module 16 4 00043 Step 8 Check Automatic Choke Operation Test Procedure See Figure 8 Crank engine while ob serving choke operation The Choke Solenold CS should pull in to close choke for about 0 2 0 4 seconds should then de energize to open choke for about 2 seconds This cyclic action should occur while the engine is cranking Choke Solenold does not actuate check for binding Also check for proper choke adjustment see ADJUSTMENTS section Test Results A Choke operation checks GOOD engine still won t start Go to Step 9 B Choke operation checks BAD Try adjusting choke if it still does not operate replace Choke Module Figure 8 Automatic Choke Step 9 Check Engine Compresslon Condition Test Procedure Refer to section entitled ENGINE TROUBLESHOOTING If ne
37. gs If they are dull or tamished polish with fine sandpaper DO NOT USE ANY METALLIC GRIT TO CLEAN SLIP RINGS Use low pressure air 25 psi or tess to blow away cleaning residue 22 2 Set a VOM to its Rx1 scale and zero the meter Connect VOM positive test lead to the positive Slip Ring nearest the Rotor bearing Connect negative VOM test tead to the negative Sip Ring Meter should indicate the following resistance plus or minus 10 at 20 C 68 F NP45G Units 13 9 ohms NP55G Units 15 5 ohms NP65G Units z 11 1 ohms 3 Reassembie Brushes and Brush Holder retain Brush Holder and Wires Make sure Brushes are seated in Brush Holder and are contacting the Slip Rings ro Rotate Rotor several times to seat Brushes against Slip Rings Test Results A Rotor circuit checks GOOD Go to Step 10 B Rotor circuit tests BAD Repair or replace defective wire s or brushes Replace defective Rotor Assembly Step 10 Check Voltage Regulator Sensing NOTE Sensing signals to the Electronic Voltage Regulator are dellvered via Wires 11 and 22 Loss o hese sensing signals to the Regulator due to an open or shorted condition in a non compensated Regulator normally means a Full Field condition output voltage will drop dramatically Total a c volt age output from the Stator a c power windings will a result of residual Rotor magnetism only Test Procedure Recheck Wires 11 and 22 between
38. hm Milliammeter having a DIODE TEST capability be used The solld state cir ult that regulates automatic choke opening and losing cannot be tested In the field That circuit will be tested In Step 8 by observing choke operation Test Procedure See Figure 7 Disconnect all wires from Choke Module terminals to prevent interactlon Then proceed as follows 1 To test the Wire 14 diode connect one VOM test lead to Terminal 3 of the Choke Module connect second test lead to Terminal 1 Observe the meter reading Then reverse the test leads reverse the d c polarity across those Choke Module terminals and again observe the reading At one polarity the VOM should read infinity At the opposite polarity the VOM should indicate the for ward resistance of the 6 amp 100 volts diode In the Wire 14 circuit If using a VOM having the diode test feature allowable vollage drop across the diode is 0 6 to 0 8 volt 2 To test the Field Boost diode and resistor connect one VOM test lead to Choke Module Terminal 3 the second test lead to Terminal 2 Note the meter reading Then reverse the test leads reverse polarity and again ob serve the VOM reading At one polarity the meter should indicate infinity At the opposite polarity the meter should read the forward resistance of the diode plus the resis tance of the Field Boost Resistor a VOM having the diode test feature is used allowable voltage drop will be 0 6 to 0 8 volts PLUS the volta
39. inding 1 84 ohms Stator a c Power Windings 0 29 ohm Rotor Windings 15 5 ohms Serles generators are designed and manufactured by A GENERAC CORPORATION e P O BOX 8 WAUKESHA WI 53187 in 414 544 4811 FAX 414 544 4851 gt Revision 4 08 31 91 rela enema PR
40. ine A shorted condition in the generator or electrical loads connected to the generator can also appear to be an underpowered engine Checking Engine Compression Forinstructions and Information on checking engine com pression refer to the ENGINE SERVICE MANUAL it compression is poor look for 1 Loose spark plug s 2 Loose cylinder head bolts 3 Blown head gasket s 4 Bumed valves or valve seats 5 Insufficlent valve tappet clearance 6 Warped cylinder head s 7 Warped valve stems 8 Worn cylinder bore and or rings 9 Broke connecting rod s Check Engine Ignition Checkout and servicing of the engine ignition system is discussed in detail in the ENGINE SERVICE MANUAL To check Ignition system operation connect a SPARK TESTER to the end of a the Spark Plug wires Then crank the engine with both spark plugs removed If a hot blue spark jumps the Spark Tester gap you may assume the Ignition System is working properly if spark jumps the Tester gap you may wish to try new spark plugs If spark does NOT Jump the Tester gap look for 1 Defective gnition Module s IM1 and IM2 2 Defective Ignition Shutdown Module ISD 3 Defective Control Relay CR2 NOTE If engine runs but misses during operation check to see If ignition System Is at fault by connect Ing the Spark Tester between the high tension Spa Plug wire and the Spark Plugs A spark miss will be nt Check Carburetion See TROUBLESHOO
41. ion Resis tance tester follow the tester manufacturer s In this Manual to Stator or Rotor windings The Hi Pot Tester A he Hi Pot tester shown is only one of many brands available It is equipped with an On Off switch The pilot Lamp glows to indicate tester power is available The breakdown lamp will light to indicate failure of the winding being tested Testing Stator Insulation Gain Access to Stator Leads Remove screws that retain the front panel to the panel housing Remove the generator cover Inside the panel housing locate the Electronic Voltage Regulator and the 30 amp Circult Breaker CB1 C Disconnect Stator Leads Disconnect Stator a c output wires 11 and 22 from the Electronic Voltage Regulator terminals Disconnect Stator Wire 33 from the 30 amp Breaker CB1 Separate wires 22 and 44 at their junction Finally disconnect Stator Excitation Winding Wires 2 and 6 from the Electronic Voltage Regulator terminals DANGER Follow the Instructions carefully Wire erminal ends must not be touching any part of the generator when HI Pot voltage is appiled Do not xceed the recommended voltages Apply voltage 15 for a maximum of 1 second only Test All Stator Windings to Ground Connect terminal ends of Stator a c output Wires 11 22 33 44 2 and 6 tightly together Make sure no terminal end is in contact with the generator frame Then proceed as follows 1 Connect RED test lead of Hi Po
42. its retaining bracket Slide the CHOKE SOLENOID in the slotted holes to ad just axial movement of the SOLENOID plunger Adjust the axial movement so that with the carburetor choke plate closed the CHOKE SOLENOID plunger Is just bot in the solenoid coil plunger at full actuated posi tion With choke plate closed and plunger bottomed in the coil tighten the two screws Then crank engine and check choke operation AIR CLEANER SHOWN REMOVED FOR CLARITY CARBURETOR LLU SLOTTED HOLES BI METAL lee j SOLENOID PLUNGER SOLENOID CHOKE 75464 EXPLODED VIEW OF ENGINE ENCLOSURE SEE EXP VIEW OF CARBURATOR Exploded View of Sheet Metai Drawing No 75464 ITEM 1 RNZSGSTROSRZRZEBE PART NO 67877 67198 N 67890 74915 63036 74904 56892 70520 74903 74916 74908 73190 73189 73188 74902 43146 22097 73191 48571 22129 75246 11 74260 74900 73186 23484 22717 8 22717 67866 74855 74965 22447 40936 48031 47662 BB 74956 42807 46509 08 74260 09 74260 48031 D 29289 73132 REQ D 1 DESCRIPTION ENGINE ASSY See EXPLODED VIEW OF V TWIN ENGINE KEY Woodruff 6 x 25 WASHER Belleville NUT Hex M20 1 50 SCREEN Air Inlet SCREW Crimptite No 8 32 x 1 4 HOUSING Engine
43. loads applied check the a c voltage and frequency readings Voltage should be atieast 116 volts frequency should be at least 58 Hz or higher Test Results if voltage and frequency are good at no load but drop excessively when electrical loads are applied check the following A Generator may be overloaded Add up the wattage or amperage of all electrical loads being operated at one 20 time This total should be less than the generator s rated wattage amperage capacity Reduce electrica loading as necessary B A ground fault condition may exist in the generator or on one or more connected electrica loads This can increase current flow dramatically and may cause circuit breakers to trip See INSULATION RESISTANCE TESTS on Page 9 C Loss of engine power may have occurred Check engine for adequate air flow clogged air cleaner incor rect ignition timing mechanical failure incorrectly ad justed carburetor etc Complete repairs to engine as necessary Step 5 Check Adjust Engine Governor Test Procedure If the no load voltage and frequency are both correspondingly high or low adjustment of the engine governor may be required See ADJUSTMENTS section Following govemor adjustment to the correct a c frequency the a c voltage must be checked If engine speed frequency is correct but a c voltage is not adjust ment of the Electronic Voltage Regulator may be re quired Test Results A Voltage and Frequ
44. oad 3720 rpm Rotor amp Stator Winding Nominal Resistance Rotor amp Stator Winding Nomina Resistance Battery Charge Windings 0 12 ohm Battery Charge Windings 0 07 ohm Excitation Winding 2 21 ohms Excitation Winding 1 67 ohms Stator a c Power Windings 0 42 ohm Stator a c Power WindingS 0 23 ohm Rotor Windings 13 9 ohms Rotor 11 1 ohms Series NP55G All units can be reconnected to 120 240 volts 1 phase 60 Hz a c output See GENERATOR A C CONNEC Rated Maximum 5500 watts TION SYSTEM on Page 5 Rated a c 120 volts Rated Maximum Current At 120 volts 45 8 amps 90 0205000900000400000090090009009099909990 9 46009009290909200009909092222290920040900004000040090940025000909 6 Govemed Rotor Speed at No Load 3720 rpm Rotor amp Stator Winding Nominal Resistance Battery Charge WindingS 0 09 ohm Excitation W
45. ow Creates a Magnetic Field When ever electrical current flows through a wire or coil of wire a magnetic field is created around that wire The strength of the field depends on the amount of current flow and ihe number of coils or loops in the wire C A simple a c generator consists of a spinning mag netic field called a ROTOR and stationary coll of wire called a STATOR As the Rotor spins its lines of mag netic force cut across the stationary Stator When the ends of the Stator winding are connected across a load such as a light bulb to complete the circuit current will flow through the circuit In this simple generator the Rotor is a permanent magnet The amount of voltage and current flow induced into the Stator windings depends on a the Rotor s magnetic field strength b Rotor rotational speed and c the number of turns of wire in the Stator A More Sophisticated a c Generator D A more sophisticated generator is equipped with a Stator a c power winding and a Stator excitation winding Regulated direct current from the excitation winding flows through carbon brushes which slide on metallic slip rings and then through the Rotor windings Regulated current flow through the Rotor creates a regulated magnetic field strength In turn the regulated magnetic fleld strength induces a regulated voltage into the stationary Stator winding BATTERY OR OC POWER SOURC EXCITATION WINDING MESS STATOA SLIP RI
46. r the Switch contacts are open and the circuit is incomplete 5 Battery voltage is available to the Battery Charge Rec tifier BCR via Wire 13 15 amp Fuse F1 Wire 15 and to a Battery Charge Rectifier BCR However BCR diode action inhibits current flow Circuit Condition Engine Cranking When the Start Stop Switchis held at its START posi tion the following sequence of events occurs 1 Start Stop Switch closure connects the Control Relay CR2 and the Starter Contactor SC actuating colls to frame ground 2 The Starter Contactor SC energizes and its contacts close to deliver battery voltage to a Starter Motor SM and b a Choke Solenoid CS and c a Choke Module CM The following events then occur a ao Motor SM energizes and the engine cranks b Battery vonage is defivered to the Choke Module via Wire Choke Module CM action opens and closes this circuit to ground at a rate dependent on ambient temperature to energize and de energize the Choke Solenoid Choke Solenoid CS opens and closes the carburetor choke c Battery voltage detivered to the Choke Module is detivered to the generator Rotor windings via a Field Boost Resistor and Diode housed in the Choke Module Wire 4 and the Rotor brushes and slip rings This is field boost LEGEND BCR BATTERY CHARGE RECTIFIER CB1 o CIRCUIT BREAKER 30 AMP CB2 o CIRCUIT BREAKER CH CHOKE HEATER CM CHOKE MODULE
47. rature Switch contacts check GOOD Go to Step 4 B Temperature Switch contacts check BAD Check wiring Step 4 Check Control Relay CR1 Test Procedure Refer to Step 6 under Problem No 1 Test Results A Control Relay CR1 checks GOOD Go to Step 5 Control Relay CR1 checks BAD Replace Control Relay CR1 Step 5 Check Stator Battery Charge Windings NOTE The Volt Ohm Milllammeter VOM used tc est Stator windings must be accurate Recom ended Is a digital meter of high accuracy Test Procedure Disconnect Wires 66 and 77 Fig 11 from the Battery Charge Rectifier BCR terminals Seta VOM to its Rx1 scale and zero the meter Connect the meter test leads across the terminal ends of Wires 66 and 77 just removed from Battery Charge Rectifier BCR The VOM should indicate Stator Battery Charge Winding resistance as follows Series NP45G 0 12 chm Series NP55G 0 09 ohm Series NP65G 0 07 ohm All test readings are plus or minus 10 Now set the VOM to its 10 000 scale and zero the meter Connect one VOM test lead to terminal end of Wire 66 remaining test lead to a clean frame ground No upscale movement of the meter should be noted infinity Test Results A Battery Charge Winding checks GOOD Go to Step 6 B Battery Charge Winding checks BAD Replace Stator Assembly Figure 11 Checking Stator Battery Charge Windings STATOR ASSEMBLY Step 6 Check Resistor R1 Test Procedure In
48. roblem No 2 Engine Cranks Won t Start Step 1 Check Fuel Quantlty Test Procedure When troubleshooting a problem the most simple causes are often overlooked engine cranks normally but won t start cheok that adequate supply of the proper fuel is available Many RV generator installations with shared fuel tank utilize a generator fuel pickup tube that is shorter than the vehicle engine s fuel pickup tube For that reason the generator will run out of gas while fuel is still available for the vehicle engine Test Results A Fuel quantity is adequate Go to Step 2 B inadequate fuel In tank Fill fuel tank Step 2 Check Fuel Shutoff Valves Test Procedure The fu l supply line in th vehicle may be equipped with one or more fuel shutoff valves If engine will not start check that ail fuel supply valves are open Test Results A Fuel Shutoff Vaive s are closed Open all valves B Shutoff vaives are open engine will not start Go to Step 3 Step 3 Check Fuel Flow Gasoline System Only Test Procedure Disconnect fuel at engine car buretor inlet Crank engine and check fuel flow from open end of disconnected line Test Results A Fuel Flow is inadequate Go to Step 4 B Fuel flow checks GOOD Go to Step 6 Step 4 Check Fuel Filter Gasoline System Only Test Procedure Seo Figure 6 If uel flow to carburetor is low try a new fuel filter Make sure arrow on filter body points in direction of
49. side the generator panel locate Resistor R1 Fig 12 Test wire 0 between Resistor 1 and frame ground connection for an open condition Correct open condition if necessary before proceeding Disconnect Wire 55 form the Resistor to prevent interac tion Set a VOM to its Rx1 scale and zero the meter Connect the first meter test probe to the Wire 55 terminal of Resistor Connect second test probe to a clean frame ground Meter should indicate about 1 chm plus or minus 5 Test Results A Resistor Rt checks GOOD Repeat Steps 1 through 4 under Problem No 3 Resistor Ri checks BAD Replace Resistor R1 Figure 12 Resistor R1 T BATTERY CHARGE WINDING i GROUND Problem No 4 Engine Starts Hard Runs Rough Step 1 Check Engine Ignition System Test Procedure Refer to ENGINE TROUBLESHOOT ING section Also see ENGINE SERVICE MANUAL Test Results A Ignition system checks GOOD Go to Step 2 B Ignition system checks BAD Repair or replace defec tive component s Step 2 Check Carburetion Test Procedure See ENGINE TROUBLESHOOTING section Also see ENGINE SERVICE MANUAL Test Results A Checks GOOD Go to Step 3 B Checks BAD Adjust repair or replace as necessary Step 3 Check Engine Compression Test Procedure Refer to ENGINE TROUBLESHOOT ING section Also see ENGINE SERVICE MANUAL Test Results A Engine checks GOOD Go to Step 4 B Engine checks BAD Repair
50. t tester to joined ter minal ends of Wires 11 22 33 44 2 and 6 2 Connect the BLACK test lead to a clean painted frame ground on generator Stator can 3 Turn Hi Pot tester switch OFF Then plug tester Into a 120 volts wali socket and set its Voltage Selector Switch to 500 volts CAUTIONI IN STEP 4 DO NOT APPLY VOLTAGE LONGER THAN ONE MINUTE 4 Tum tester switch ON and check that Pilot Lamp is ON Then set Voltage Selector Switch to 2000 volts Observe the BREAKDOWN tamp wait one second then tum tester switch OFF STATOR ASSEMBLY Test Between isolated Windings To test between iso lated Stator windings proceed as follows 1 Connect RED lead of Hi Pot tester to terminal end of Wire 11 BLACK test lead to Wire 2 terminal end 2 Tum tester switch ON and check that Pilot Light Is ON 3 Set Voltage Selector Switch to 1500 volts APPLY VOLTAGE FOR ONE SECOND ONLY Observe tester Breakdown lamp Tum tester switch OFF and reset Vol tage Selector Switch to 500 volts Test Between Parallel Windings Test between paral lel Stator windings as follows 1 Set tester Voltage Selector Switch 0 500 volts 2 Connect tester RED test lead to Wire 11 BLACK test lead to Wire 33 3 Turn tester switch ON and check that Pilot Light is ON 4 Apply voltage for one second while observing the Breakdown lamp Then turn tester switch OFF RESULTS If tester Breakdown lamp comes ON during any one second test
51. top Switch 17 17 Meter 19 Step 2 Check Wire 18 Test Procedure Refer to WIRING DIAGRAM Page 11 Test Wire 18 between Ignition Shutdown Module ISD and Start Stop Switch for open or shorted condition Also check Wire 18 between Start Stop Switch and Control Relay CR2 for open or shorted condition Test Results A Wire 18 checks GOOD Go to Step 3 B Wire 18 checks BAD Repair or replace Step 3 Check Engine Ignition System Test Procedure See ENGINE TROUBLESHOOTING section in this Manual Also see ENGINE SERVICE MANUAL Test Results Repair or replace defective ignition components as necessary Problem No 6 Loss of Generator a c Output Step 1 Check Circuit Breakers CB1 CB2 TestProcedure Try resetting applicable circuit breaker If this does not correct the problem use a VOM to test the circuit breakers Test Results A Problem is corrected by resetting Breaker STOP test B Circuit Breaker tests GOOD stili little or no a c output Go to Step 2 C Circuit Breaker tests BAD Replace Circuit Breaker s Step 2 Check Vehicle Wiring Test Procedure Check vehicle a c wiring and a c dis tribution components Test Results A Vehicle wiring checks GOOD Go to Step 3 B Vehicle wiring checks BAD Repair or replace as needed Step 3 Check a c Voltage and Frequency Test Procedures Check generator a c output voltage frequency Fig 14 as follows 1 Disconnect generator a c outp
52. tor SM C Engine cranks normally with jumper cable and with Start Stop Switch STOP tests NOTE For Starter Motor SM testing and repair structions refer to ENGINE SERVICE MANUAL Step 5 Check Start Stop Switch SW1 Test Procedure See Figure 3 Test the Start Stop Switch as follows 1 Set a Volt Ohm Milliammeter VOM to its Rx1 scale and zero the meter Connect one VOM test lead to the Wire 0 terminal of Start Stop Switch connect second meter test lead to a clean frame ground The VOM should indicate continuity Test Results A VOM does NOT indicate continuity Repair or replace Wire 0 between Switch and frame ground connection as necessary B VOM indicates continuity Continue test Figure 3 Start Stop Switch Terminals 17 17 2 Connect a jumper wire between the Start Stop Switch Wire 17 terminal and a clean frame ground connection Engine should crank and start Disconnect jumper wire to terminate cranking when engine starts To stop the en gine connect jumper wire to Wire 18 terminal of Start Stop Switch and to frame ground Test Results A Engine cranks starts and shuts down normally when using jumper wire but not when using Start Stop Switch Replace Start Stop Switch B Engine will not crank when using jumper wire Go to Step 6 C Engine cranks and stops normally when using jumper wire and with Start Stop Switch STOP tests Step 6 Check Control Relay CR1 NOTE See WIRING
53. ut leads T1 red T2 white and T3 black in the junction box where they connect to vehide wiring 2 Connect an accurate a c voltmeter and frequency meter across generator a c output leads T1 red and T2 white 3 Start the generator engine let it stabilize and warm up at NO LOAD Figure 14 Test Points for Voltage Frequency 4 Read the a c voltage and frequency Indicated readings should be 124 volts at 62 Hz Test Results A Voitage and Frequency check GOOD Go to Step 4 B Voltage and Frequency are both high or low Go to Step 5 C Low or no a c voltage Go to Step 6 D Frequency GOOD Voits HIGH Go to Step 10 Step 4 Check Load Voltage and Frequency OTE the no load voltage and frequency were within specified iimits but operational problems occur when electrical loads are applied check the voltage and frequency under toad Test Procedure Proceed as follows 1 Check that load leads are properly connected to a c output terminals T1 red T2 white and T3 black 2 Connect an accurate a c voltmeter and frequency meter to a c output leads Connect meters across leads T1 red and T2 white 3 Start the generator engine let it stabilize and warm up Then tum ON electrical loads by whatever means provided such as double throw switch or circuit breaker Apply loads as close as possible to the units rated maximum continuous wattage amperage capacity 4 With rated
54. utomotive type battery charger to recharge the battery to a 100 state of charge DANGER Storage batteries give off EXPLOSIVE hydrogen gas while charging Completely remove he battery from the vehicle before attempting to recharge It Charge the battery only In a well venti lated space where explosive gases Cannot accumu late and present the danger of explosion Do not per mit smoking open or sparks in the vicinity battery 3 If the difference in specific gravity between the highest and lowest reading cell is 0 050 50 points or greater the battery is nearing the end of its useful life and should be replaced However the lowest reading cell has a specific gravity of less than 1 200 recharge the battery and then repeat the specific gravity test If after charg ing the difference between the highest and lowest read ing cell is still 0 050 50 points replace the battery Test Results A Normal engine cranking occurs STOP tests B Battery checks GOOD no cranking Go to Step 3 Figure 1 Starter Contactor SC Step 4 Check Starter Motor SM Test Procedure Connect a jumper cable to the large battery cable terminal stud Wire 13 of the Starter Con 13 tactor and to the cable terminal on Starter Motor Engine should crank Test Results A Engine cranks normally but does not crank when using the Start Stop Switch Go to Step 5 8 Engine does NOT crank Replace Starter Mo
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