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Generator

Fundamentals

Basic Electricity

3

Magnetism and Electricity

3

Electro-Motive Force

4

Electromagnetism 7

Direct Current (DC) 

8

Alternating Current (AC) 

8

Volt

10

Ampere

10

Ohm

10

Ohm’s Law 

11

The Watt

11

Electrical Formulas

12

The Series Circuit 

13

The Parallel Circuit 

13

The Series-Parallel Circuit

14

Simple Alternator

17

Simple Alternator  Operation

17

Generator Components

And Systems

Generator Components

19

Rotor Assembly 

20

Stator Assembly 

21

Switches 23

Fuses 26

Circuit Breakers 

26

Solenoids 27

Relays 28

Resistors 29

Transformers 31

Condensers 32

Rectifiers 33

Transistors 34

Brushes and Brush Holders 

35

Voltage Regulator 

37

Generator Systems

41

Revolving Field Excitation Methods 

42

Direct Excitation 

42

The Brushless Excitation Method 

44

Field Boost Assembly 

45

Power Factor 

46

Oil Pressure Switch On “GN” Engines 

49

Typical Automatic Idle Control System 

50

Early V-Twin Engine Idle Control 

51

Idle Control on “GN”
190, 220, 320, 360, & 410 ENGINES 

51

“XL”   And “MC”  Idle  Control  On
480 & 570 V-Twin Engines 

53

1

GENERAC

®

PORTABLE PRODUCTS 

Table of Contents

Portable Generator Familiarization & Troubleshooting Guide

Summary of Contents for 86262GS

Page 1: ...Familiarization Troubleshooting Guide GENERATOR For Briggs Stratton Discount Parts Call 606 678 9623 or 606 561 4983 www mymowerparts com...

Page 2: ...ne who uses a procedure or method not described by the manufacturer must first satisfy himself that neither his safety nor the safety of the product will be endangered by the service or operating proc...

Page 3: ...itches 23 Fuses 26 Circuit Breakers 26 Solenoids 27 Relays 28 Resistors 29 Transformers 31 Condensers 32 Rectifiers 33 Transistors 34 Brushes and Brush Holders 35 Voltage Regulator 37 Generator System...

Page 4: ...roubleshooting Flowchart For Sincro Wound Brushless Type Generators 84 Voltage Regulator Adjustments 90 Generator Assemblies Generac Wound Generators 94 Disassembly 94 Assembly 101 Sincro Wound Genera...

Page 5: ...other In a normal atom the positive charge of the nucleus exactly balances the negative charge of the electrons that rotate around it Borrowing Of Electrons If an atom loses electrons the positive ch...

Page 6: ...theories is mentioned because the conventional theory is more commonly used in everyday applications For this guide however we will use the Electron Theory Electro Motive Force Current flow occurs in...

Page 7: ...n or subtraction of heat energy will set these electrons free Figure 1 5 shows a union between iron and copper wires this union forms a thermocouple In Figure 1 5A the heat of the flame has caused the...

Page 8: ...direction of magnetic lines of force around a wire you can use a simple rule called the Right Hand Rule Simply place your right hand around the wire with your thumb pointing in the direction of the c...

Page 9: ...nt flow through a primary coil of wires creates a magnetic field around that coil which then cuts through a secondary coil of wires When the current flow through the primary wire coil is interrupted b...

Page 10: ...10 amperes through 100 coils of wire will each create a magnetic field strength 1000 ampere turns Figure 1 13 The term ampere turns is the measure of the strength of a magnetic field Direct Current DC...

Page 11: ...ee the Table 1 1 A wave diagram sine wave of alternating current shows that current goes from a zero value to maximum positive value 0 90 degrees and then returns to zero Figure 1 15 Two such current...

Page 12: ...e is equal to a little over six thousand million billion electrons per second Written numerically the figure looks like this 6 000 000 000 000 000 000 Volt Unit of Pressure The volt is a measurement o...

Page 13: ...s Law may be stated as follows Amperage will increase whenever voltage increases and resistance remains the same Amperage will decrease whenever resistance increases and voltage remains the same Ohm s...

Page 14: ...ELECTRICAL FORMULAS Section 1 Generator Fundamentals Portable Generator Familiarization Troubleshooting Guide 12...

Page 15: ...a series circuit is the sum of the individual resistances The total voltage across all resistances loads in series is the sum of the voltages across the individual resistances Thus total resistance ma...

Page 16: ...d the total resistance of such a circuit first determine the resistance of each group The sum of the two group resistances is the total circuit resistance You can treat the two groups of resistances e...

Page 17: ...TA Connected or Wye Connected Re connnectable Figure 1 26 Connections Affecting Circuits It is necessary to become familiar with some of the terms used to describe conditions which adversely affect th...

Page 18: ...16 Section 1 Generator Fundamentals Portable Generator Familiarization Troubleshooting Guide Figure 1 26 Some Examples of 3 Phase Connection System...

Page 19: ...netic field of the rotor has more wire turns to cut through on the stator The Revolving Magnetic Field The rotor is essentially an electro magnet The flow of direct current DC through its windings cre...

Page 20: ...Section 1 Generator Fundamentals Portable Generator Familiarization Troubleshooting Guide 18...

Page 21: ...er of parts However these parts are expensive and should not be replaced needlessly Replacement of parts as a result of guesswork while troubleshooting is not cost effective and should be avoided Figu...

Page 22: ...e applied Several different engine manufacturers may be found on the various Generac Portable Products generator models They include Briggs Stratton Tecumseh Kawasaki Honda Robin Generac Power Systems...

Page 23: ...half the driven speed of the 2 pole rotor Figure 2 3 Stator Assembly The word stator means stationary winding A voltage or electromotive force EMF is induced into the stator by the action of rotating...

Page 24: ...citation winding AC output is delivered to a bridge rectifier Figure 2 8 which converts its output to direct current DC The rectifier direct current output is delivered to the rotor windings XL MC Ser...

Page 25: ...A switch may be defined as a device used to open close or divert an electrical circuit You can actuate switches manually or automatically This discussion is devoted solely to manually operated switche...

Page 26: ...ion Troubleshooting Guide Figure 2 12 Single Pole Single Throw SPST Figure 2 13 Single Pole Double Throw SPDT Figure 2 14 Double Pole Single Throw DPST Figure 2 17 Four Pole Double Throw 4PDT Figure 2...

Page 27: ...n in Figure 2 19 In general this type of switch may be classified by The number of poles The number of positions Figure 2 20 illustrates single pole double pole 3 pole and 4 pole rotary switches 25 Se...

Page 28: ...dings that are in series with the circuit to be protected When current flow exceeds a pre determined value the coil s magnetic field becomes strong enough to open a set of contact points and open or b...

Page 29: ...l pressure shutdown switch used on some generator engines This type of switch is normally closed NC and is held open by engine oil pressure during engine operation Should engine oil pressure drop belo...

Page 30: ...to the relay winding the spring holds the armature contacts against the upper fixed contact When current flow is applied to the winding a magnetic field is created The winding becomes an electromagne...

Page 31: ...riable resistor is provided with some means of manipulating the length of the resistor element One type of variable resistor is called a potentiometer or rheostat which is usually wire wound The amoun...

Page 32: ...nce to excessive voltages in circuits You could call them voltage sensitive Figure 2 34 shows a silicone carbide resistor along with its schematic symbol This type of variable resistor is often used t...

Page 33: ...s indicated by the letter P When the switch is closed current flow through the primary winding increases which expands lines of magnetic force that cut across the secondary winding This causes a volta...

Page 34: ...as heat energy in the resistor The capacitor will then be said to be discharged Figure 2 37 However if a wire is connected between the two plates if you touch the two capacitor wires together the exce...

Page 35: ...ot flow in the opposite direction The rectifier thus permits one alternating current to pass but blocks the reverse alternation This action results in a pulsating direct current DC flow A rectifier th...

Page 36: ...ight damage some components in a circuit or to protect transistors against excessive current flow For example A zener diode rated at 10VAC acts much like any other diode up to 10VAC However if the app...

Page 37: ...rger current flow across the emitter collector Some Typical Transistors Some typical transistors are displayed in Figure 2 44 Generally the larger the transistor s physical size the more current it ca...

Page 38: ...o terminals indicated by an E Wire 4 from the positive brush connects to the terminal indicated by a Brush lead 1 connects to the terminal More recent units are equipped with a rectifier and brush hol...

Page 39: ...slip rings strengthening the magnetic field Voltage Regulator There are three variations of the voltage regulator shown in Figure 2 51 The regulator itself is the same for each one Only the connector...

Page 40: ...tz AC frequency will provide a 60VAC output and so on A conventional voltage regulator provides a fixed voltage output regardless of frequency If output frequency is held constant voltage will remain...

Page 41: ...o have a system control circuit board which is usually housed in the control or receptacle panel Operation of this type of system is similar to the conventional voltage regulator system However voltag...

Page 42: ...the power regulator board to turn on and increase current flow to the rotor This causes the rotor s magnetic field strength to increase and actual voltage to increase When actual voltage is more than...

Page 43: ...e winding is changed to direct current DC by one or more diodes in the circuit Early production units were equipped with battery charge circuits as shown in Figure 2 61 consisting of a single winding...

Page 44: ...in the rotor creates magnetic lines of flux which cut through stator windings A and B to induce an EMF into both windings Winding B is the Direct Excitation Winding The EMF induced into this winding...

Page 45: ...excitation current is taken from instead of having an A and B winding Compare Figure 2 64 with 2 66 The operation of a Reactor Excited alternator may be described as follows The Rotor turns at a pre...

Page 46: ...t is intersected by the rotor winding as it is spun by the engine That induces an AC voltage in the rotor winding that is converted to a DC voltage by a diode in the rotor winding This creates an elec...

Page 47: ...g start up residual AC voltage is delivered to the PTC and diode from the stator power winding When the thermistor is cold resistance is low Current can flow to the diode where the AC current is recti...

Page 48: ...e power Such a condition would exist when a reactance condition occurs in a circuit To help explain the reason for apparent and true power ratings of reactance circuits mechanical work can be related...

Page 49: ...47 Section 2 Generator Components Systems Portable Generator Familiarization Troubleshooting Guide Figure 2 73 Determining The Power Factor...

Page 50: ...ash while the engine is cranking To reset the float switch and allow the engine to start fill the crankcase to the proper level with the recommended oil THE V TWIN ENGINE SYSTEM The V Twin engine has...

Page 51: ...below approximately 10 psi 0 32 kg per cm2 The system control circuit board provides a time delay that allows oil pressure to build during initial cranking The delay permits the engine to run for abou...

Page 52: ...is shut down the throttle is held against the high speed side of a throttle stop During operation at no load and with the idle control switch set to OFF the flapper will be at approximately the no loa...

Page 53: ...the coil and reduce engine speed to idle Early V Twin Engine Idle Control The V Twin idle control system operates in a fashion similar to the idle control on other portable generators For units with i...

Page 54: ...ose the circuit to the idle control coil delivering 120VDC to the coil With the coil energized the governor lever will be pulled in to reduce engine speed to idle about 40 45 Hertz When electrical loa...

Page 55: ...secondary windings The idle control board will sense there is no load on the generator and will send a signal to the idle control stepper motor The stepper motor will move to the low idle position wh...

Page 56: ...54 Section 2 Generator Components Systems Portable Generator Familiarization Troubleshooting Guide...

Page 57: ...bare wires terminals etc Never permit an untrained person to service or assist with the procedures discussed in this guide Never handle any kind of electrical cord or device while standing in water wh...

Page 58: ...HOOTING IDLE CONTROLS Section 3 Generator Diagnostics and Adjustments Portable Generator Familiarization Troubleshooting Guide control Figure 3 1 Idle Control Troubleshooting Flow Chart 3500 7500 Watt...

Page 59: ...s an electromagnet Touch the shaft of a screwdriver to the idle control coil If the solenoid is energized the screwdriver should stick to the side of the coil If the screwdriver sticks but the engine...

Page 60: ...with the idle control switch ON The system control board is bad Check the idle control coil for shorts NOTE A shorted coil can damage the system control board Be sure to adjust the voltage potentiome...

Page 61: ...59 Section 3 Generator Diagnostics and Adjustments Portable Generator Familiarization Troubleshooting Guide...

Page 62: ...tion 3 Generator Diagnostics and Adjustments Portable Generator Familiarization Troubleshooting Guide Figure 3 4 Idle Control Troubleshooting Flow Chart 480 570 V Twin GN Engines 8000 10000 Watt Gener...

Page 63: ...but DC voltage is not present at pins J2 and J3 check for a failure in the battery charge circuit of the generator Test 3 Check Idle Control Switch Operation Remove wires 83 and 84 from the idle cont...

Page 64: ...ess and the stepper motor housing ground the VOM should read infinity If any reading other than listed is noted replace the stepper motor and harness as an assembly Early Idle Control Adjustment Excep...

Page 65: ...eed Turn the idle mixture valve in lean until the engine begins to roughen and then out rich until it roughens Take note of these positions Set idle mixture valve midway between rich and lean Recheck...

Page 66: ...cy adjustments should only be done after successfully completing the No Load adjustments Refer to Figure 3 12 Perform steps with the engine running at its correct no load frequency Then proceed as fol...

Page 67: ...t NOTE The Idle Control Switch adjustment should only be done after successfully completing No Load Rated Load and Low Idle frequency adjustments Proceed with the idle control switch adjustments with...

Page 68: ...pm For units rated at 50 Hertz Meter should read About 50 5 51 5 Hertz 3030 3090 rpm Set the idle control switch to ON The idle control solenoid should energize to pull the governor lever in and engin...

Page 69: ...Using a phillips screwdriver Adjust the low speed adjustment screw Figure 3 16 to 45 Hz Turn the Idle Switch to OFF Adjust the high speed adjustment screw Figure 3 16 to 62 Hz no load Cycle the idle...

Page 70: ...TING GENERATOR UNITS Section 3 Generator Diagnostics and Adjustments Portable Generator Familiarization Troubleshooting Guide or later Figure 3 17 Troubleshooting Flow Chart For Direct Excited Brush T...

Page 71: ...ple process involving a DC battery This usually occurs if the unit is out of use for a long period of time NOTE Some units are equipped with FIELD BOOST and should never lose residual magnetism unless...

Page 72: ...r voltage regulator For that reason if a rotor has failed be sure to check the bridge rectifier voltage regulator or power regulator board Before testing the rotor inspect the brushes and slip rings R...

Page 73: ...4 and the positive post on a 12VDC battery Connect a jumper wire between the negative brush and the negative post on the battery See Figure 3 23 Start the engine and monitor amp draw It should not ch...

Page 74: ...h resistance indicates an opening in the excitation winding A low reading indicates a shorted stator winding Connect one test lead to a stator power wire Connect the other test lead to one of the stat...

Page 75: ...wer Windings Set a VOM to the OHM scale Connect the test leads to the stator wires 11 and 22 Measure the resistance and compare it to the nominal resistance from the appropriate table Briggs Stratton...

Page 76: ...fier NOTE Bypassing the bridge rectifier and voltage regulator are similar tests the difference being that six wires are unplugged from the voltage regulator where only two or four are removed from th...

Page 77: ...tor current draw is within specification The problem is in the stator windings If the rotor current draw Test 3 is higher than specified A flying short exists in the rotor If current draw Test 3 is lo...

Page 78: ...76 Section 3 Generator Diagnostics and Adjustments Portable Generator Familiarization Troubleshooting Guide Figure 3 31 Troubleshooting Flow Chart For Brush Type Generators With Two Board Regulation...

Page 79: ...by flashing the field with a simple process involving a DC battery This usually occurs if the unit is out of use for a long period of time NOTE Some units are equipped with FIELD BOOST and should nev...

Page 80: ...was disconnected Figure 3 34 Start the engine Measure the voltage at the 120VAC panel receptacle It should read less than 10VAC If the voltage is less than 10VAC The failure is in the System Control B...

Page 81: ...stator windings Refer to Checking Rotor Resistance Checking Stator Windings and or Rotor Current Draw Test If the voltage is below 60VAC at the outlets but above 60VAC at the excitation leads Shut the...

Page 82: ...nce table Briggs Stratton Power Products Portable Generator Rotor Stator Resistance Tables Pub 87971 Rev 6 or later A reading of infinity or a very high resistance indicates an open circuit or a parti...

Page 83: ...s higher than specified a flying short exists in the rotor If current draw is lower than specified a flying open exists in the rotor If current draw is within specifications rotor is OK Test 8 Check S...

Page 84: ...ting Single Voltage Type Power Winding Set a VOM to its OHM scale Connect the meter test leads across the AC power wires Wire 11 and wire 22 or blue and red wires Figure 3 44 Measure the resistance an...

Page 85: ...or Stator Resistance Tables Pub 87971 Rev 6 or later Connect the test leads to the stator wires 22 and 44 Measure the resistance and compare it to the nominal resistance from the appropriate table Ana...

Page 86: ...84 Section 3 Generator Diagnostics and Adjustments Portable Generator Familiarization Troubleshooting Guide Figure 3 46 Troubleshooting Flow Chart For Sincro Wound Brushless Type Generators...

Page 87: ...excitation system an energizing cord may be made locally Figure 3 47 Make sure the generator is completely assembled Plug one end of the energizing cord into one of the panel 120VAC receptacles Start...

Page 88: ...citation wires Figure 3 51 Measure the resistance and compare it to the nominal resistance from the appropriate table Briggs Stratton Power Products Portable Generator Rotor Stator Resistance Tables P...

Page 89: ...r test lead to the stator power winding Figure 3 55 A reading of infinity should be measured A reading of other than infinity indicates a stator winding shorted to ground Testing Dual Voltage Type Pow...

Page 90: ...rotor capacitor from each other Set a VOM meter to the ohm scale Connect the VOM test probes across the rotor winding previously disconnected from the rotor diode and capacitor Briggs Stratton Power P...

Page 91: ...istor or capacitor fails and the winding is ok replace the diode assembly If the rotor tests are OK Re solder the three leads that were removed from the crimp and proceed to Test 5 Check Adjust Engine...

Page 92: ...gine running at its correct no load speed Slowly turn the voltage adjust pot Figure 3 59 until no load voltage is 124VAC line to neutral or 248VAC line to line Units rated at 110 220 VAC With engine r...

Page 93: ...ontrol circuit board These two components share the voltage regulation process See UNITS WITH POWER REGULATOR SYSTEM CONTROL CIRCUIT BOARD on page 39 Although the voltage regulation process is shared...

Page 94: ...92 Section 3 Generator Diagnostics and Adjustments Portable Generator Familiarization Troubleshooting Guide...

Page 95: ...prying Medium external snap ring pliers Available Service Kits Rotor Removal Kit Part 41079 Electronic Measuring Equipment The measuring equipment used in troubleshooting should be of industrial quali...

Page 96: ...s well as problems with wiring connections Before continuing with the disassembly process visually inspect for the following Evidence of bearing failure Very fine metallic dust that generally accumula...

Page 97: ...or housing from the plug Electrical Measurements NOTE Many of the electrical measurements that are necessary to accurately troubleshoot the Generac wound generator are accessible at this point In orde...

Page 98: ...minal will slide out of the connector housing as shown in Figure 4 8 Repeat this process until all the terminals are removed from the connector housing When all of the terminals are free of the housin...

Page 99: ...cks remove the four stator bolts that hold the rear bearing carrier and stator to the engine adapter Figure 4 13 With the stator bolts removed grip the rear bearing carrier and work it free from the r...

Page 100: ...r keyway driving the rotor Very often removing the through bolt leaves the rotor attached to the tapered shaft This is due to heat of operation and the compression of the rotor bolt when it is properl...

Page 101: ...he rotor bolt diameter is1 4 inch Use the 3 8 24 tap Figure 4 19 Item 4 to cut internal threads at the bearing end of the rotor shaft If the rotor shaft is 5 16 inch Use the7 16 20 tap Figure 4 19 Ite...

Page 102: ...e appropriate thread pitch Figure 4 19 Item 1 or 2 into the threaded I D of the rotor shaft Tighten the capscrew firmly against the slotted end of the stud See Figure 4 23 Strike the head of the capsc...

Page 103: ...otor Figure 4 25 Start the bolt into the threads of the tapered shaft by hand being careful not to crossthread the bolt Torque to specifications NOTE Torque specifications can be found in the appendix...

Page 104: ...on the rear bearing carrier consists of a roll pin pressed into the inside flange Viewed from the outside of the carrier it would located at the 7 o clock position just inboard and slightly below the...

Page 105: ...directly against the actual laminations of the stator without any gap inside the flange of the carrier Figure 4 33 All the alignment pins and notches should be in their proper orientation All the asse...

Page 106: ...to ensure that nothing is internally bound grating or rubbing Assembling The Wiring Harness Install the protective mesh over the power wires as shown in Figure 4 36 NOTE Refer to the specific wiring...

Page 107: ...ing the generator from resting in its cradle You should have retained two star washers and 1 wing nut from disassembly Install one star washer on the grounding lug Then the terminal lug for the ground...

Page 108: ...as shown in Figure 4 42 and tighten screws finger tight Torque mounting screws Figure 4 43 to specifications in the torque chart found in the appendix of this guide Install Vibration Mounts to Cradle...

Page 109: ...gure 4 46 Ensure that the louvers are up as shown Place the tab at the top of the cover over the grommet Install the cover with the screws you retained from disassembly Torque to specifications found...

Page 110: ...108 Section 4 Generator Assemblies Portable Generator Familiarization Troubleshooting Guide...

Page 111: ...g the access cover to the end of the sincro generator Figure 4 49 This exposes the components shown below in Figure 4 50 A visual inspection of this area can reveal both mechanical problems as well as...

Page 112: ...rement locations are described in the section titled Troubleshooting Flow Chart For Sincro Wound Brushless Type Generators which begins on page 84 Removing The Capacitor Remove the capacitor from its...

Page 113: ...e mounting stud breaks free before the nut It is ok to remove the nut and stud together With an assistant to help secure the complete unit a short block of wood and a large soft mallet Tap the stator...

Page 114: ...ious failure or for rotor replacement Inspect for any loose debris obstructions or flaws on the engine adaptor stator laminations rear bearing carrier the threaded hole in the tapered shaft and the su...

Page 115: ...e 4 62 Reinstall the grounding wire as shown in Figure 4 63 Remove the supporting blocks and seat the isolation mount studs through their holes in the cradle frame Install the nuts you retained from d...

Page 116: ...ess cover with the louvered half down as shown in Figure 4 68 Reinstall access cover with the hardware you retained from disassembly Insure that there are no obstructions to the rotation of the rotor...

Page 117: ...115 Section 4 Generator Assemblies Portable Generator Familiarization Troubleshooting Guide...

Page 118: ...116 Section 4 Generator Assemblies Portable Generator Familiarization Troubleshooting Guide...

Page 119: ...GENERAC TORQUE TABLE Appendix A Portable Generator Familiarization Troubleshooting Guide 117...

Page 120: ...s Configuration NEMA 68868 22693 58888 74190 58889 L5 30P 5 15P L5 20P 6 15P 66883 26338 93568 58890 120 120 125 240 30 15 20 15 L5 30R 5 15R L5 20R 6 15R Receptacle No Plug Part No Volts Amps Configu...

Page 121: ...bleshooting Guide Receptacle No Plug Part No Volts Amps Configuration NEMA 63025 68759 5 15P 5 20P 26338 120 120 15 20 5 15R DUPLEX 5 20R DUPLEX Receptacle No Plug Part No Volts Amps Configuration NEM...

Page 122: ...of electricity CYCLE One complete reversal of alternating current of voltage from zero to a positive maximum to zero to a negative maximum back to zero The number of cycles per second is the frequency...

Page 123: ...e current flows different in phase by 120 degrees from each other RATED SPEED Revolutions per minute at which the set is designed to operate RATED VOLTAGE The rated voltage of an engine generator set...

Page 124: ...or potential difference expressed in volts VOLTAGE REGULATOR A component which automatically maintains proper generator voltage by controlling the amount of DC excitation to the rotor WATT Unit of el...

Page 125: ...123 Appendix A Portable Generator Familiarization Troubleshooting Guide...

Page 126: ...Appendix A Portable Generator Familiarization Troubleshooting Guide 124...

Page 127: ......

Page 128: ...re e W Wa as sh he er r F Fa am mi il li ia ar ri iz za at ti io on n T Tr ro ou ub bl le es sh ho oo ot ti in ng g G Gu ui id de e 1 19 90 02 27 75 5 H Ha an nd d H He el ld d G Ge en ne er ra at to...

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