Generac Power Systems 941-2 Service Manual
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Generac Power Systems 941-2 Service Manual

Generac Power Systems 941-2 Service Manual

Generac impact 36 plus ii service manual
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Manual Part No. 0D9057
SERVICE
MANUAL
SERIES IMPACT 36 PLUS II
Models 940-2 & 941-2
P. O. B ox 2 9 7 • W h i t ewa t e r, W I • 5 3 1 9 0
Phone: (262) 473-5514
Fax: (262) 472-6505
Printed in U.S.A
Revision A - 07/15/03

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Summary of Contents for Generac Power Systems 941-2

  • Page 1 SERVICE MANUAL SERIES IMPACT 36 PLUS II Models 940-2 & 941-2 P. O. B ox 2 9 7 • W h i t ewa t e r, W I • 5 3 1 9 0 Phone: (262) 473-5514 Fax: (262) 472-6505 Printed in U.S.A...
  • Page 2 Throughout this publication, "DANGER!" and "CAUTION!" blocks are used to alert the mechanic to special instructions concerning a particular service or operation that might be hazardous if performed incorrectly or carelessly. PAY CLOSE ATTENTION TO THEM. DANGER! UNDER THIS HEADING WILL BE FOUND SPECIAL INSTRUCTIONS WHICH, IF NOT COM- PLIED WITH, COULD RESULT IN PERSONAL INJURY OR DEATH.

  • Page 3: Table Of Contents

    SERVICE MANUAL SERIES IMPACT 36 PLUS II TABLE OF CONTENTS PART TITLE THE AC GENERATOR ENGINE MECHANICAL GASOLINE FUEL SYSTEM GASEOUS FUEL SYSTEM ENGINE OIL & COOLING SYSTEM ENGINE ELECTRICAL SYSTEM TROUBLESHOOTING SPECIFICATIONS & CHARTS...
  • Page 5 PART 1 GENERAL INFORMATION COMPUTER CONTROLLED VARIABLE SPEED RV GENERATORS Series Impact 36 Plus II SECTION TITLE GENERATOR FUNDAMENTALS GENERATOR MAJOR COMPONENTS OPERATIONAL ANALYSIS INSULATION RESISTANCE COMPONENTS TESTING CONTROL PANEL SHEET METAL Page 1...
  • Page 6 NOTES...
  • Page 7 MAGNETISM Magnetism can be used to produce electricity and electricity can be used to produce magnetism. Much about magnetism cannot be explained by our present knowledge. However, there are certain pat- terns of behavior that are known. Application of these behavior patterns has led to the development of gen- erators, motors and numerous other devices that uti- lize magnetism to produce and use electrical energy.
  • Page 8 Section 1.1 GENERATOR FUNDAMENTALS ALTERNATING CURRENT A simple generator consists of a coil of wires called a Stator and a magnetic field called a Rotor. As the Rotor's magnetic field cuts across the Stator coil, a voltage is induced into the Stator windings. The amount of induced voltage is equal to the strength of the magnetic field.

  • Page 9: Generator Fundamentals

    Figure 6. Electrical Units OHM: The OHM is the unit of RESISTANCE. In every circuit there is a natural resistance or opposition to the flow of electrons. When an EMF is applied to a complete circuit, the electrons are forced to flow in a single direction rather than their free or orbiting pattern.
  • Page 10 Section 1.1 GENERATOR FUNDAMENTALS CAPACITIVE REACTANCE: This condition occurs when current leads voltage (Figure 9). It might be thought of as the ability to oppose change in voltage. Capacitance exists in a circuit when certain devices are ~a) capable of storing electrical charges as voltage increases and (b) discharging these stored charges when the voltage decreases.
  • Page 11 3. When the generator circuit breaker is turned to the “ON” position, AC voltage is delivered to the Full Bridge Rectifier. The AC volt- age is rectified to DC and thus becomes DC Link voltage. 4. AC voltage from the stator PS1/PS2 is delivered to the inverter. This is used as the power supply for the inverter circuit board.
  • Page 12 Section 1.1 GENERATOR FUNDAMENTALS Page 1.1-6...

  • Page 13: Major Generator Components

    INTRODUCTION Major components of the generator proper are shown in Figure 1, below. External sheet metal and other unrelated components are omitted from the drawing for clarity. These parts are: Item Description Upper Fan Housing Upper Cooling Fan Permanent Magnet Rotor Rotor Hub Stator Retaining Ring Stator Assembly...
  • Page 14 Section 1.2 MAJOR GENERATOR COMPONENTS ROTOR HUB See Figure 2 on previous page. The Rotor Hub is bal- anced with the Rotor and must be replaced with the Rotor as an assembly. Part of the engine ignition sys- tem is pressed onto the Hub and can be replaced only as part of the Rotor and Hub assembly.
  • Page 15 Section 1.2 MAJOR GENERATOR COMPONENTS Figure 5. Schematic- Stator Windings Page 1.2-3...
  • Page 16 Section 1.2 MAJOR GENERATOR COMPONENTS Page 1.2-4...
  • Page 17 GENERAL Figure 1, below, is a block diagram of the Impact Plus computer controlled RV generator. The diagram is Intended only for the purpose of illustrating generator operation. Refer to the actual wiring diagram for wiring interconnections. OPERATIONAL DESCRIPTION 1. The Impact Plus is a computer controlled generator that uses an inverter to create a superior sine wave and maintain a steady frequency of 60 Hz.
  • Page 18 Section 1.3 OPERATIONAL ANALYSIS OPERATIONAL DESCRIPTION (CONTINUED) 7. The A6060 circuit board controls all functions of the generator, i.e.: a. Engine DC control system b. Stepper motor operation (1) If voltage is low, the board will signal a STEPPER MOTOR to change engine throt- tle setting and increase speed until the desired voltage level is reached.

  • Page 19: Insulation Resistance

    DIRT AND MOISTURE If moisture is permitted to remain in contact with the generator Stator windings, some of it will be retained in voids and cracks of the winding insulation. This can eventually cause a reduction in insulation resistance and generator output may be affected. Winding insulation in Generac generators is moisture resistant.
  • Page 20 Section 1.4 INSULATION RESISTANCE TEST ALL STATOR WINDINGS TO GROUND Connect the ends of all Stator leads together. Make sure none of the leads are touching any terminal or any part of the generator. Connect one Tester probe to the junction of all Stator leads;...
  • Page 21 Figure 3. Schematic - Stator Windings USING SOLVENTS FOR CLEANING: A solvent is generally required when dirt contains oil or grease. Only petroleum distillates should be used to clean electrical components. Recommended are safety type petroleum solvents having a flash point greater than 100°...
  • Page 22 Section 1.4 INSULATION RESISTANCE Page 1.4-4...
  • Page 23 INTRODUCTION Problems that occur In the computer-controlled RV generator generally involve the following systems or components: 1. The engine. 2. The Speed Control System. 3. The AC Generator. 4. Battery Charge Circuit. 5. A6060 Circuit Board. 6. Wiring Harness and Front Panel. This Section will discuss test procedures for the fol- lowing components.
  • Page 24 Section 1.5 COMPONENTS TESTING STATOR ASSEMBLY (CONTINUED) Figure 2. Schematic- Stator Windings TESTING POWER SUPPLY WINDINGS: A. To test the Power Supply winding for an open circuit condition, proceed as follows: 1. Disconnect the 2-wire power supply from the generator. See Figure 3. 2.
  • Page 25 7. Connect one test lead to Stator lead PS1, the other to Stator lead 77. The VOM should read "infinity". 8. Connect one VOM test lead to Stator lead TIM1, the other test lead to Stator lead 77. "Infinity" should be Indicated. TESTING THE BATTERY CHARGE CIRCUIT GENERAL: The Stator is equipped with dual battery charge wind-...
  • Page 26 Section 1.5 COMPONENTS TESTING Page 1.5-4...

  • Page 27: Control Panel

    CONSTRUCTION The panel is constructed of sheet metal and includes a panel box, a panel back cover and a front control panel. The panel box is retained to an engine-genera- tor divider plate by five M5 screws. Removal of these screws will permit the panel to be removed from the divider plate and set out of the way with connecting wires still attached.
  • Page 28 Section 1.6 CONTROL PANEL Page 1.6-2...
  • Page 29 See "Exploded View of Sheet Metal" on next page. A DIVIDER PLATE (Item 1) separates the AC generator components from the engine. The engine Itself is enclosed by a BASE HOUSING WRAPPER (Item 4), a FRAME (Item 24), and a BELLY PAN (Item 23). These components are sealed by means of rubber SEALS (Items 3), to prevent GENERAL...
  • Page 30 Section 1.7 SHEET METAL EXPLODED VIEW OF SHEET METAL (GASOLINE UNITS) Page 1.7-2 13 19 TO CARBURETOR...
  • Page 31 PARTS LIST FOR SHEET METAL (GASOLINE UNITS) ITEM DESCRIPTION PLATE, DIVIDER M6-1.0 HEX NUT SEAL RUBBER EXTRUSION 3.5 FT WRAPPER, BOX TAPTITE, M5- .8 x 10MM LONG MOUNTING RAILS M8 LOCK WASHER M8-1.25 x 35MM HEX HD. CAPSCR. HHCS M5-0.8 x 40MM SPARK ARRESTOR U-BOLT, W/SADDLE &...
  • Page 32 Section 1.7 SHEET METAL EXPLODED VIEW OF SHEET METAL (LP UNITS) Page 1.7-4 51 19 30 59...
  • Page 33 PARTS LIST FOR SHEET METAL (GASOLINE UNITS) ITEM DESCRIPTION PLATE, DIVIDER CRIMPTITE 10-24 x 1/2" 3.5' SEAL, RUBBER EXTRUSION BOX, WRAPPER TAPTITE, M5-.8 x 10MM MOUNTING RAILS M8 LOCK WASHER M8-1.25 x 35MM HEX HD. CAPSCR. HHCS M5-0.8 x 40MM WRAPPER, END PANEL SPARK ARRESTER DEFLECTOR, AIR OUT...
  • Page 34 Section 1.7 SHEET METAL Page 1.7-6...
  • Page 35 PART 2 ENGINE MECHANICAL COMPUTER CONTROLLED VARIABLE SPEED RV GENERATORS Series Impact 36 Plus SECTION TITLE GENERAL INFORMATION VALVE TRAIN PISTON, RINGS, CONNECTING ROD CRANKSHAFT & CAMSHAFT...
  • Page 36 NOTES...
  • Page 37 Section 2.1 GENERAL INFORMATION INTRODUCTION The engine used on Impact 36 plus Series recreational vehicle AC generators is a Generac Series GV-220, vertical shaft, single cylinder, overhead valve type. These engines are not equipped with a mechanical engine governor. Instead. variable engine speeds are controlled by a computer circuit board.

  • Page 38: Gaseous Fuel System

    Section 2.1 GENERAL INFORMATION TIMING: Valve timing and ignition timing must be precisely controlled if the engine is to operate properly and effi- ciently. Intake and exhaust valves must open and close in a precise timed sequence if the four strokes are to occur.
  • Page 39 Engine crankcase oil capacity without oil filter change is about 29 fluid ounces (850m. Engine crankcase oil capacity (with oil filter change) is about 1 U.S. quart (946m1). Change engine oil and the oil filter after the first eight (8) hours of operation. Thereafter, change engine oil and oil filter every 50 operating hours.
  • Page 40 Section 2.1 GENERAL INFORMATION ITEM DESCRIPTION Connecting Rod Piston Pin Piston Ring Set (STD) 1/4" Pipe Plug Breather Cover Piston Piston Pin Retainer Crankshaft & Gear Assembly Oil Breather Separator Crankcase Assembly Sleeve Bearing Crankshaft Oil Seal Breather Baffle Cup M6 Screw Lockwasher Dowel Sleeve...

  • Page 41: Valve Train

    VALVE TRAIN COMPONENTS Valve train components are listed below and shown in Figure 1, below. ITEM DESCRIPTION Tappet Push Rod Rocker Arm Pivot Ball Stud Rocker Arm Jam Nut Push Rod Guide Plate Valve Spring Valve Spring Retainer Valve Spring Washer Exhaust Valve Intake Valve Figure 1.
  • Page 42 Section 2.2 VALVE TRAIN Figure 4. Cylinder Head Removal DANGER! ALWAYS WEAR SAFETY GLASSES WHEN REMOVING THE VALVE SPRINGS. 5. See Figure 5, next page. Hold the valve with your fingers while compressing the spring with your thumb, then proceed as fol- lows: a.
  • Page 43 NOTE: After the valve guides have been over- sized, be sure to recut the valve seats so they will align with the guides. Figure 8. Valve Guides VALVE TAPPETS: Valve tappets can be removed during removal of the engine camshaft. Intake and exhaust valve tappets are identical.
  • Page 44 Section 2.2 VALVE TRAIN VALVE COMPONENTS INSTALLATION (CONTINUED) 3. Install the valve spring washers, valve springs and valve spring retainers over the valve guides. a. Hold the valve with your fingers and use your thumbs to compress the spring. b. When the spring is compressed sufficiently, slide the spring retainer small opening over the valve stem.
  • Page 45 VALVE CLEARANCE GV-220 ENGINE INTAKE VALVE: 0.001-0.0022 inch (0.03-0.056mm) EXHAUST VALVE: 0.0018-0.003 inch (0.046-0.07mm) Adjust the valve clearance as follows: 1. Rotate the crankshaft until the piston is at top dead center (TDC) of its compression stroke. Both valves should be closed. 2.
  • Page 46 Section 2.2 VALVE TRAIN Page 2.2-6...
  • Page 47 OVERSIZE PISTON & RINGS Worn or scored cylinders may be rebored to 0.010 (0.25mm) or 0.020 (0.50mm) oversize. Pistons and piston rings of matching oversize are available to fit the rebored cylinder. Figure 1. Piston, Rings and Connecting Rod PRIOR TO REMOVAL Before removing pistons, rings and connecting rod, clean all carbon from the cylinder bore.
  • Page 48 Section 2.3 PISTON, RINGS, CONNECTING ROD Figure 4. Piston Minor Diameter PISTON MINOR DIAMETER GV-220) Design DIAMETER: 2.747-2.748 inch (69.789-69.809mm) Figure 5. Piston Major Diameter PISTON MAJOR DIAMETER GV-220) Design DIAMETER: 2.753-2.754 inch (69.939-69.959mm) NOTE: Always apply engine oil to wrist pin and its bores during Installation.
  • Page 49 Figure 7. Ring Locations in Piston Grooves CHECKING PISTON RING END GAP: To check piston rings end gap, proceed as follows (see Figure 8): 1. Locate a point inside the cylinder that is 2.75 inches (70mm) down from top of cylinder. This is approximately half-way down.
  • Page 50 Section 2.3 PISTON, RINGS, CONNECTING ROD hammer handle to gently tap the piston down into the cylinder. 4. Check that the connecting rod's large diameter bearing is coat- ed with oil, as well as the crank throw and the connecting rod cap.
  • Page 51 GENERAL Prior to removal of the crankcase cover, gain access to the engine and generator by removing surrounding sheet metal as required. See Section 1.6. CRANKCASE COVER REMOVAL Before attempting to remove the crankcase cover, remove rust, paint and burrs from the power takeoff (PTO) end of the crankshaft.
  • Page 52 Section 2.4 CRANKSHAFT AND CAMSHAFT CAMSHAFT INSPECTION Carefully inspect the entire camshaft for wear, nicks, damage. All areas indicated in Figure 4 should be checked for wear. Figure 4. Points to Check on Camshaft The following should be measured carefully to check for wear: MAIN CAMSHAFT BEARING DIAMETER (FLYWHEEL END)
  • Page 53 Figure 6. Bearing Bore in Crankcase Cover COMPRESSION RELEASE MECHANISM A mechanical compression release is provided on the camshaft. See Figure 7. A PIN extends over the cam lobe. This PIN pushes on the tappet, to lift the valve and relieve compression for easier cranking. When the engine starts, centrifugal force moves the FLY- WEIGHT outward against SPRING force.
  • Page 54 Section 2.4 CRANKSHAFT AND CAMSHAFT Figure 9. Timing Mark on Crankshaft Gear Figure 10. Alignment of Timing Marks Page 2.3-8...

  • Page 55: Gasoline Fuel System

    PART 3 GASOLINE FUEL SYSTEM COMPUTER CONTROLLED VARIABLE SPEED RV GENERATORS Series Impact 36 Plus SECTION TITLE INTRODUCTION TO FUEL SYSTEM AIR CLEANER & AIR INTAKE FILTER & FUEL PUMP CARBURETOR AUTOMATIC CHOKE SPEED CONTROL SYSTEM...
  • Page 56 NOTES Page 2...
  • Page 57 GENERAL Recreational vehicle generators equipped with a gasoline fuel system are usually installed so that they share the fuel supply tank with the vehicle engine. When this is done, the generator Installer must never tee off the vehicle fuel supply line to deliver fuel to the generator.
  • Page 58 Section 3.1 INTRODUCTION TO FUEL SYSTEM altered. Service technicians working on the RV gener- ator systems must not do anything that might change the vehicle fuel system design. Figure 2. Typical Gasoline Fuel System Page 3.1-2...
  • Page 59 AIR CLEANER DESCRIPTION: The air cleaner assembly consists of (a) an air clean- er BASE, (b) a PAPER FILTER, and (c) a COVER. See Figure 1. Figure 1. Engine Air Cleaner SERVICING THE AIR CLEANER: Clean or replace the PAPER FILTER every 25 hours of operation or once each year, whichever comes first.
  • Page 60 Section 3.2 AIR CLEANER AND INTAKE Page 3.2-2...
  • Page 61 FUEL FILTER The fuel filter should be removed and replaced every 100 hours of operation or once each year, whichever occurs first. Figure 1. Fuel Filter (Typical) FUEL PUMP DESCRIPTION: The 12 volts DC electric fuel pump has a zinc plate finish.
  • Page 62 Section 3.3 FUEL FILTER AND FUEL PUMP Page 3.3-2...
  • Page 63 GENERAL INFORMATION Proper engine performance depends on the carbure- tion system. The use of clean, fresh gasoline and a well-maintained air cleaner are extremely important to proper operation, as well as engine reliability and power. Most causes of carburetion problems are related to the use of stale, gummy fuel and the ingestion of dirt.
  • Page 64 Section 3.4 CARBURETOR CARBURETOR DISASSEMBLY See Figure 3. The carburetor can be disassembled as follows: 1. Remove the BOWL NUT (Item 3) and the FIBER WASHER (Item 4). Then, remove the FLOAT BOWL (Item 5). 2. Remove the FLOAT PIN (Item 6). Then, remove the FLOAT (Item 7) and the INLET VALVE (Item 8).
  • Page 65 ADJUSTMENT The carburetor used on the GV-220 engine has a FIXED, NON-ADJUSTABLE Low Speed Jet. ENGINE SPEED Engine speed is controlled by the A6060 circuit board. That circuit board signals a stepper motor which moves the throttle linkage. Engine speed will vary in response to changes in generator AC output voltage.
  • Page 66 Section 3.4 CARBURETOR Figure 6. Carburetor Removal Page 3.4-4...
  • Page 67 GENERAL The GV-220 vertical shaft engines are equipped with an automatic choke. A choke solenoid is attached to the carburetor choke shaft by means of a choke con- trol link. Solenoid operation is controlled by the A6060 circuit board. The circuit board energizes and de- energizes the solenoid cyclically at a rate dependent on ambient temperature during engine cranking only.
  • Page 68 Section 3.5 AUTOMATIC CHOKE Page 3.5-2...
  • Page 69 GENERAL The AC generator's output voltage is controlled by a "computerized" speed control system. This system changes engine speed in response to changes in the AC output voltage at varying engine loads. The speed control system consists of (a) the A6060 circuit board and (b) a stepper motor.
  • Page 70 Section 3.6 SPEED CONTROL SYSTEM ELECTRICAL CONNECTIONS BROKEN: If one or more of the electrical connections to the stepper motor are broken or disconnected, either of the following might occur: 1. The stepper motor may not turn at all. 2. The stepper motor may turn erratically. If the stepper motor does not turn, symptoms will be the same as for a failed or seized stepper motor.

  • Page 71: Gaseous Fuel System

    PART 4 GASEOUS FUEL SYSTEM COMPUTER CONTROLLED VARIABLE SPEED RV GENERATORS Series Impact 36 Plus SECTION TITLE INTRODUCTION TO FUEL SYSTEM SHUTOFF VALVE & REGULATOR CARBURETOR NOTE: Information on the following is the same as for the "GASOLINE FUEL SYSTEM" (Part 3): Air Cleaner &...
  • Page 72 NOTES...
  • Page 73 GENERAL INFORMATION Some RV generator models are equipped with fuel systems that utilize LP gas as a fuel. The initials "LP" stand for "liquefied petroleum". This gas is highly volatile and can be dangerous if handled or stored carelessly. All applicable laws, codes and regulations pertaining to the storage and handling of LP gas must be com- plied with.
  • Page 74 Section 4.1 INTRODUCTION TO FUEL SYSTEM IMPORTANT CONSIDERATIONS (CONTINUED) NOTE: A PRIMARY REGULATOR, between the tank and the fuel lockoff solenoid, is required to ensure that correct gas pressure is delivered to the lockoff solenoid. • The generator installer's connection point is at the fuel lockoff solenoid which has a 3/4 inch (female) connection.
  • Page 75 GASEOUS CARBURETION Gas at positive pressure is delivered from the fuel lockoff solenoid to the inlet of the regulator (about 11- 14 inches of water). As the engine piston moves downward on its intake stroke, air is drawn into the area above the piston through the carburetor venturi.
  • Page 76 Section 4.1 INTRODUCTION TO FUEL SYSTEM Page 4.1-4...
  • Page 77 GENERAL See Figure 1. The fuel shutoff valve (lockoff solenoid) and the secondary regulator are retained to a flat mounting bracket which, in turn, mounts to the gener- ator base cover. The fuel lockoff solenoid is retained to the mounting bracket by means of a u-bolt. The secondary regulator is retained to the mounting bracket with two 1/4"-20 x 3/4"...
  • Page 78 Section 4.2 SHUTOFF VALVE AND REGULATOR TEST PROCEDURE: 1. Set a volt-ohm-milliammeter (VOM) to read battery voltage (12 VDC). 2. Connect the VOM test leads across Wire 14 (Red) at the sole- noid and a clean frame ground. 3. Set the fuel primer switch on the generator panel to its ON position.
  • Page 79 GENERAL The carburetor is designed for use with LP gas in its vapor form. The following specifications apply: Carburetor Inlet Diameter...1.02inch (26mm) Carburetor Outlet Diameter ...0.78 inch (20mm) Venturi Diameter ...0.63 inch (16mm) Main Jet Diameter Number ...370 Measured Size ...0.145 inch (3.7mm) CARBURETION Refer to "Gaseous Carburetion"...
  • Page 80 Section 4.3 CARBURETOR Page 4.3-2...

  • Page 81: Engine Oil & Cooling System

    PART 5 ENGINE OIL & COOLING SYSTEM COMPUTER CONTROLLED VARIABLE SPEED RV GENERATORS Series Impact 36 Plus SECTION TITLE ENGINE OIL SYSTEM ENGINE COOLING SYSTEM...
  • Page 82 NOTES...
  • Page 83 INTRODUCTION TO OIL SYSTEM The engine oil system serves to (a) reduce friction between parts, (b) cool the engine, and (c) establish a slightly negative pressure in the crankcase to prevent oil leakage. Major components that will be discussed in this section include the following: •...
  • Page 84 Section 5.1 ENGINE OIL SYSTEM OIL PUMP (CONTINUED) INSPECTION (CONT'D): Inspect the outer drive pins on the camshaft. Look for breakage, bending, other damage. These are roll pins which can be removed and replaced. Figure 3. Oil Pump Check Points CRANKSHAFT OIL SEALS An oil seal is provided in the crankcase and in the oil sump, to prevent leakage past the crankshaft jour-...
  • Page 85 The breather serves to maintain a partial vacuum in the engine crankcase, to prevent oil from being forced past oil seals, gaskets or rings. See Figure 6. A reed type breather valve permits excess pressure to be vented out of the crankcase and to atmosphere through a breather tube.
  • Page 86 Section 5.1 ENGINE OIL SYSTEM Page 5.1-4...
  • Page 87 It is absolutely essential that an adequate flow of air for cooling, ventilating and engine combustion be sup- plied to the generator set. Without sufficient air flow, the engine-generator quickly overheats. Such over- heating can cause serious operating difficulties and may also cause fire and personal injury.
  • Page 88 Section 5.2 ENGINE COOLING SYSTEM Figure 3 — Suspended Mount Inlet Door Figure 4. Ductwork Figure 5 — Air Inlet in Vehicle Skirt Page 5.2-2 COMPENSATING FOR RESTRICTIONS Such materials as screening, louvers, or expanded metal can restrict the free flow of air. Compensate for this restriction by making the actual air opening pro- portionately larger.

  • Page 89: Engine Electrical System

    PART 6 ENGINE ELECTRICAL SYSTEM COMPUTER CONTROLLED VARIABLE SPEED RV GENERATORS Series Impact 36 Plus SECTION TITLE ENGINE DC CONTROL SYSTEM A6060 CIRCUIT BOARD ENGINE CRANKING SYSTEM ENGINE IGNITION SYSTEM ENGINE SHUTDOWN FEATURES OPTIONAL REMOTE PANEL...
  • Page 90 NOTES...
  • Page 91 GENERAL The engine DC control system consists of all those electrical components required for cranking, starting and running the engine. These components include the following: 1. Engine cranking system components a. A 12 VDC battery. b. A Start-Run-Stop Switch (SW1). c.
  • Page 92 Section 6.1 ENGINE DC CONTROL SYSTEM HOW IT WORKS ENGINE NOT RUNNING: 1. Battery output (12VDC) is available to the contacts of a starter contactor (SC). However, the contacts are open. 2. Battery output is delivered to Terminals J2 - 5 of the A6060 cir- cuit board, via Wire 13, a 15 amp fuse, and Wire 15.
  • Page 93 GENERAL The A6060 circuit board controls all phases of engine operation including cranking, starting, running and shutdown. The circuit board interconnects with other compo- nents of the engine electrical system. The board Is powered by fused 12 VDC battery out- put, available to the board via Wire 15.
  • Page 94 Section 6.2 A6060 CIRCUIT BOARD CIRCUIT BOARD CONNECTIONS (CONTINUED) RECEPTACLE J4: The A6060 circuit board mounts a 3-pin receptacle J4. A 3-pin connector plug connects to the A6060. This harness then connects to Bridge Rectifier. DC Link Voltage is supplied to the circuit board for volt- age sensing.
  • Page 95 INTRODUCTION COMPONENTS: The engine cranking system is shown schematically in Figure 1, below. The system consists of the follow- ing components: • A 12 volts Battery. • A Start-Run-Stop Switch (SW1). • A Starter Contactor (SC). • A Starter Motor (SM1). •...
  • Page 96 Section 6.3 ENGINE CRANKING SYSTEM BATTERY (CONTINUED) TESTING A BATTERY: The best method of testing a battery is with an auto- motive type battery hydrometer. Some "Maintenance Free" batteries cannot be tested with a hydrometer. Most batteries can be tested for both STATE OF CHARGE and CONDITION as follows: 1.
  • Page 97 Section 6.3 ENGINE CRANKING SYSTEM STARTER MOTOR DESCRIPTION: The Starter Motor is a 12 volts negative ground type. It is capable of operating on heavy duty battery input at temperatures as low as -30 F. without any signifi- cant change in performance. Its pinion is a 10-tooth type having a 20- pressure angle.
  • Page 98 Section 6.3 ENGINE CRANKING SYSTEM Page 6.3-4...
  • Page 99 INTRODUCTION The engine ignition system consists of the following major components: • Ignition Cage Assembly. • Ignition Sensor Assembly. • Ignition Module (IM). • Ignition Coil (IC). • Spark Plug (SP1). IGNITION CAGE ASSEMBLY An IGNITION CAGE ASSEMBLY is factory installed onto the permanent magnet rotor hub.
  • Page 100 Section 6.4 ENGINE IGNITION SYSTEM IGNITION MODULE (CONTINUED) Figure 4. Ignition Module IGNITION COIL Primary ignition voltage (12 VDC) is delivered from the Ignition Module to the Ignition Coil. The Coil boosts the voltage and delivers the high voltage to the engine Spark Plug.
  • Page 101 TESTING FOR SPARK: To test the ignition system, a suitable spark tester may be used. Such spark testers are commercially available. Test the system as follows: Warning! Do NOT use a screwdriver to test for spark. Personal injury or damage to equip- ment may result.
  • Page 102 Section 6.4 ENGINE IGNITION SYSTEM TESTING THE SYSTEM (CONTINUED) CHECK POWER SUPPLY (CONT’D): b. If battery voltage is NOT indicated in Step 7, test Wire 14 between the 4-terminal connector and the A6060 circuit board. Repair or replace as necessary. CHECK IGNITION SENSOR: 1.
  • Page 103 GENERAL The engine mounts an Oil Pressure Switch (LOP) and an Oil Temperature Switch (HTO). These two switch- es, in conjunction with the A6060 circuit board, pro- tect the engine against (a) low oil pressure and (b) high oil temperature. The engine protective circuit Is shown in Figure 1.
  • Page 104 Section 6.5 SHUTDOWN FEATURES ADDITIONAL SHUTDOWN FEATURES The A6060 Circuit Board also incorporates the follow- ing protective shutdown features: LOSS OF 12-PIN CABLE SIGNALS TO INVERTER: The generator will shutdown if the 12-pin connector is disconnected from the inverter when CB1 is turned to This shutdown will occur after approximately 5-7 seconds.
  • Page 105 GENERAL An optional remote-mounted Start-Stop panel is avail- able. This panel will permit the generator to be started and stopped from some convenient remote location in the recreational vehicle. REMOTE PLUG-IN RECEPTACLE A plug-in receptacle (Figure 2.24) is provided on the generator set, near the DC power wires.
  • Page 106 Section 6.6 OPTIONAL REMOTE PANEL Page 6.6-2...

  • Page 107: Troubleshooting

    PART 7 TROUBLE- SHOOTING COMPUTER CONTROLLED VARIABLE SPEED RV GENERATORS Series Impact 36 Plus SECTION TITLE GENERATOR & SPEED CONTROL ENGINE DC CONTROL SYSTEM/ AC TROUBLESHOOTING...
  • Page 108 NOTES...
  • Page 109 TROUBLESHOOTING REFERENCE CHART PROBLEM POSSIBLE CAUSE 1. Engine starts, accelerates, a. Carburetor linkage sticking with shuts down at 4500 rpm throttle stuck open. b. Stepper Motor failed or seized. c. Stepper Motor wire connections broken or disconnected. d. Stepper Motor not properly connected. 2.
  • Page 110 Section 7.1 GENERATOR & SPEED CONTROL SYSTEM Page 7.1-2...
  • Page 111 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING INTRODUCTION This Section contains troubleshooting information pertaining to the engine DC control system. The section is divided into two parts, i.e., troubleshooting flow charts and diagnostic test procedures. Use the flow charts and the test procedures in conjunction with one another. The first step in troubleshooting is to identify the problem.
  • Page 112 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING PROBLEM 2 - ENGINE WILL NOT CRANK PROBLEM 3 - ENGINE CRANKS BUT WILL NOT START Page 7.2-2...
  • Page 113 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING PROBLEM 3 - ENGINE CRANKS BUT WILL NOT START (CONTINUED) Page 7.2-3...
  • Page 114 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING PROBLEM 4 - ENGINE STARTS HARD AND RUNS ROUGH Page 7.2-4...
  • Page 115 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING PROBLEM 5 - ENGINE STARTS THEN SHUTS DOWN AFTER A FEW SECONDS SHUTS DOWN TEST 31 TEST INVERTER (Pg. 7.2-18) FAIL REPLACE INVERTER Page 7.2-5...
  • Page 116 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING PROBLEM 6 - GENERATOR DOESN’T PULL FULL LOAD PROBLEM 7 - GENERATOR CIRCUIT BREAKER TRIPS / NO AC VOLTAGE Page 7.2-6...
  • Page 117 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING PROBLEM 8 - ENGINE SHUTS DOWN UNDER LOAD PROBLEM 9 - GENERATOR LOSES AC POWER THEN SHUTS DOWN Page 7.2-7...
  • Page 118 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING PROBLEM 10 - NO AC OUTPUT 12-WIRE Page 7.2-8...
  • Page 119 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING PROBLEM 10 - NO AC OUTPUT (CONTINUED) Page 7.2-9...
  • Page 120 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING TEST 1- CHECK 7.5 AMP FUSE DISCUSSION: The panel-mounted 7.5 amp fuse is connected in series with the 12 VDC power supply to the engine DC control system. A blown fuse will prevent engine priming, cranking and running.
  • Page 121 RESULTS: 1. If unit is being tested because the priming function doesn't work: a. !f battery voltage is good but the pump doesn't work, go to Test 5. b. !f battery voltage is NOT indicated, go to Test 6. 2. If engine cranks but will not start: a.
  • Page 122 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING This test will determine if battery voltage is available to the Starter Motor for cranking the engine. TEST PROCEDURE: 1. Set a VOM to read battery voltage (12 VDC). 2. Connect the meter test leads across the starter terminal and frame ground.
  • Page 123 TEST 11- TEST STARTER CONTACTOR DISCUSSION: See "Starter Contactor" on Page 6.3-2. Replace Starter Contactor if bad. TEST 12- TEST START-STOP SWITCH DISCUSSION: Engine cranking and startup are initiated when the Start-Stop switch is held at "START" to ground Wire Engine shutdown is normally initiated when the Start- Stop switch is set to "STOP"...
  • Page 124 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING Figure 8. Checking Spark Plug Gap RESULTS: 1. Clean and regap or replace spark plug as necessary. 2. If spark plug is good but engine will not start, go to Test 3. 3.
  • Page 125 If the engine cranks but won't start, it is possible that a failure in the circuit board has occurred and DC power is not being delivered to the Wire 14 circuit. This test will determine if circuit board action will deliver battery voltage to the necessary engine components.
  • Page 126 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING ENGINE COMPRESSION PRESSURE NOMINAL PRESSURE: 60 psi MINIMUM ALLOWABLE: 55 psi NOTE: Full compression pressure cannot be obtained at cranking speeds, due to the action of a compression release mechanism. RESULTS: If compression is poor, look for one or more of the fol- lowing possible causes: 1.
  • Page 127 TEST 29 - 12 POSITION HARNESS CONTINUITY TEST 1) Set VOM to measure Resistance. 2. Measure from pin location #1 on one end of the 12 position harness to pin location #1 on the opposite end of the harness. A reading of “Continuity” should be measured. Repeat proce- dure for each pin position on the 12-wire harness.
  • Page 128 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING TEST 31 - STATIC TESTS ON INVERTER ASSUMPTION: • Inverter not connected to generator. • Inverter has been disconnected for at least 5 min- utes from running genset to allow capacitors to dis- charge.
  • Page 129 5. Momentarily jump Wire #15 (located at the fuse holder) to Wire #56 (located at the Starter Contactor). This will initiate cranking of the engine. The generator will start, but the throttle will need to be controlled manually. Hold the throttle at about a half load setting.
  • Page 130 Section 7.2 ENGINE DC CONTROL SYSTEM / AC TROUBLESHOOTING Page 7.2-20...
  • Page 131 PART 8 SPECIFICATIONS AND CHARTS COMPUTER CONTROLLED VARIABLE SPEED RV GENERATORS Series Impact 36 Plus PAGE TITLE General Specifications Nominal Resistances of Generator Windings Electrical Schematic Wiring Diagram 8-4 to 8-8 Engine Specifications Engine Torque Specifications 8-10 Major Features and Dimensions...
  • Page 132 NOTES...

  • Page 133: Specifications & Charts

    TYPE MODEL TYPE OF ROTOR RATED WATTS RATED VOLTS PHASE RATED MAXIMUM LOAD AMPERES RATED FREQUENCY OPERATING SPEED (See NOTE 1) ENGINE MODEL TYPE OF ENGINE FUEL SYSTEM COOLING SYSTEM OIL SYSTEM OIL PUMP AIR CLEANER STARTER IGNITION SYSTEM SPARK PLUG SPARK PLUG GAP NOTE 1: Engine speed will vary between approximately 2400-4000 rpm, depending on the load and load voltage.
  • Page 134 Part 8 SPECIFICATIONS & CHARTS ELECTRICAL SCHEMATIC (DRAWING NO. 0D4947-B) TIMING TIM1 TIM2 SHIELD SENSE TEMP FAN- FAN+ PWM2 PWM1 PCB1 Page 8-2 1 OF 2 CUSTOMER SUPPLIED BATTERY (LP ONLY) START STOP BATTERY CHARGE WINDING POWER WINDING POWER SUPPLY 120V CUSTOMER AC CONNECTION REMOTE...
  • Page 135 WIRING DIAGRAM (DRAWING NO. 0D4947-B) CUSTOMER SUPPLIED SHLD GRD 2 +DC BUS -DC BUS EARTH J8-1 J8-2 J11-7 PWM1 J11-4 J11-3 PWM2 J11-2 FAN+ J11-1 INVERTER J11-6 CONTROL J11-5 CHASSIS INVERTER NEUTRAL CONNECTION BY CUSTOMER GREEN BLACK WHITE LEGEND BCR - BATTERY CHARGE RECTIFIER IND - INDUCTOR ASSEMBLY BR1 - BRIDGE RECTIFIER IM - IGNITION MODULE...
  • Page 136 Part 8 SPECIFICATIONS & CHARTS MODEL BORE STROKE DISPLACEMENT OIL CAPACITY W/O FILTER CHANGE WITH FILTER CHANGE MODEL VALVE SEAT WIDTH: DESIGN WIDTH VALVE SEAT ANGLE VALVE MARGIN: DESIGN MARGIN INTAKE VALVE STEM DIAMETER: DESIGN DIAMETER EXHAUST VALVE STEM DIAMETER: DESIGN DIAMETER TAPPET DIAMETER INTAKE AND EXHAUST:...
  • Page 137 MODEL CYLINDER BORE: DESIGN DIAMETER VALVE TAPPET BORE: DESIGN DIAMETER CRANKSHAFT SLEEVE BEARING: DESIGN DIAMETER *(WHERE APPLICABLE) GOVERNOR ARM BORE: DESIGN DIAMETER CAMSHAFT BEARING: DESIGN DIAMETER GOVERNOR ARM DIAMETER: DESIGN DIAMETER: *Later model small frame GN engines have no crankshaft sleeve bearing. MODEL CRANKSHAFT BEARING BORE:...
  • Page 138 Part 8 SPECIFICATIONS & CHARTS MODEL CRANKPIN DIAMETER: DESIGN DIAMETER CRANKSHAFT MAIN BEARING (FLYWHEEL END): DESIGN DIAMETER CRANKSHAFT MAIN BEARING (PTO END): DESIGN DIAMETER MODEL LARGE END INSIDE DIAMETER: DESIGN DIAMETER SMALL END INSIDE DIAMETER: DESIGN DIAMETER PISTON PIN LENGTH: DESIGN DIAMETER PISTON PIN OUTSIDE DIAMETER:...
  • Page 139 MODEL WRIST PIN BORE DIAMETER: DESIGN DIAMETER TOP RING GROOVE WIDTH: DESIGN WIDTH SECOND RING GROOVE WIDTH: DESIGN WIDTH OIL CONTROL RING GROOVE WIDTH: DESIGN WIDTH TOP RING WIDTH: DESIGN WIDTH TOP RING END GAP: * DESIGN END GAP SECOND RING WIDTH: DESIGN WIDTH SECOND RING END GAP: * DESIGN END GAP...
  • Page 140 Part 8 SPECIFICATIONS & CHARTS MODEL MAIN CAMSHAFT BEARING DIAMETER (FLYWHEEL END): DESIGN DIAMETER MAIN CAMSHAFT BEARING DIAMETER (PTO END): DESIGN DIAMETER CAM LIFT: DESIGN LIFT BASE CIRCLE DIAMETER OF CAM: DESIGN DIAMETER COMPRESSION RELEASE LIFT (MEASURED AT TAPPET): DESIGN LIFT MODEL PUMP TIP CLEARANCE *: DESIGN CLEARANCE...
  • Page 141 OIL PUMP (CONTINUED) MODEL OIL PRESSURE RELIEF VALVE SPRING: Force required to compress spring to 1.035 inch (26.3mm) COMPRESSION PRESSURE MODEL WHILE CRANKING (COLD ENGINE) TORQUE SPECIFICATIONS MODEL Rocker Cover Screws Rocker Arm Jam Nut Cylinder Head Bolts Connecting Rod Bolts Flywheel Nut Crankcase Cover Bolts Ignition Coil Bolts...
  • Page 142 Part 8 SPECIFICATIONS & CHARTS MAJOR FEATURES AND DIMENSIONS GENERATOR Page 8-10...
  • Page 143 Part 8 SPECIFICATIONS & CHARTS MAJOR FEATURES AND DIMENSIONS INVERTER Page 8-11...

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