Engine Startup and Running | Generac Power Systems 7 kW NG, 9 kW NG

Section 4.2

Operational analysis

Part 4

DC control

Engine Startup and Running

With the fuel solenoids open and ignition occurring, the engine starts. Engine startup and running may be briefly described as follows:

•Voltage pulses from the ignition magnetos are delivered to the circuit board via Wire 18. Once the circuit board determines that the engine is running, the circuit board (a) terminates cranking, and (b) terminates the choke solenoid (CS), and (c) turns on an “engine warm-up timer”.

		POWER
		WINDING
		44
6	STATOR	22 33
2		11
		POWER

	WINDING
BA	0

4

IM2		18

SP2

	2		2
	6		6
	0	0	0	VOLTAGE
	4	0	4	REGULATOR
	4	4	4	REGULATOR
	22	4	22
	22		22
	11		11

0 4

IM1		18

SP1

8586

HTO LOP

56

00

SCR

0

0

	13
	13		13
	13	13	BATTERY
		13	BATTERY
			12V
	SCR		0
			0
	16	SC

SM

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Generac Power Systems 7 kW NG, 10 kW LP, 13 kW NG, 9 kW NG, 8 kW LP, 17 kW LP, 20 kW LP, 16 kW NG Engine Startup and Running

Contents

Air-Cooled Product Electrical formulas Automatic Operating Sequences Problem 12 No Battery Charge 147 Specifications Engine Fuel Consumption Mounting Dimensions Right Side View Major Features Door removed Part General Information Generator Identification Part IntroductionNeutral Floating Rainproof Enclosure Fitted Rated Ambient Temp 40C Installation basics Transfer Switch / Load CenterSelecting a Location Grounding The Generator Installation basics Part Typical Installation Power Source And Load Lines System Control Interconnections Natural Gas Fuel Interconnections Control Wires from Transfer Switch Non-Prepackaged Interconnections Part Non-Prepackaged Interconnections PRE 08 HSB AIR-COOLED Generators Single & V-TWIN Engines Reconfiguring The Fuel System Preparation Before Use PartGeneral Fuel Requirements Install the battery, door and close the roof Preparation before use Engine Oil Recommendations Meters VomMeasuring AC Voltage Measuring DC Voltage Measuring Current Testing, cleaning and drying PartMeasuring Resistance Ohm’s Law Electrical UnitsVolts Amps Ohms Visual Inspection Insulation ResistanceMegohmmeter ONE 1 Second Stator Insulation Resistance Test 12-20 kW Repeat between Wire 2 and Stator LeadStator Insulation Resistance Test 10 kW Cleaning The Generator Rotor Insulation Resistance Test 10 kWRotor Insulation Resistance Test 12-20 kW Drying The Generator Low Battery High Temperature SwitchLow Oil Pressure Shutdown Overspeed Shutdown Engine-generator protective devices Part Overcrank Shutdown Operating Instructions Control Panel KW Installation Assistant Operating instructions PartTo Select Automatic Operation Manual Transfer To Standby Manual Startup Automatic operating parameters Seconds then re-crank if additional crank cycles exist Automatic operating parameters Part ManualAuto Exercise Part AC Generators Engine-Generator Drive System Rotor AssemblyAC Generator Stator Assembly Description & components Description & components Part Brush Holder And Brushes 12-20 kWOther AC Generator Components Main Line Circuit Breaker Rotor Residual Magnetism Field Boost 12-20 KW Operational analysis Part Operation 8/10 kWOperation 12-20 kW Startup Troubleshooting flowcharts Troubleshooting flowcharts Part Problem 3 Generator Produces Low Voltage at No-Load Troubleshooting flowchartsProblem 4 Generator Produces High Voltage at No-Load Units with Safety Test 1 Check Main Circuit BreakerTest 2 Check AC Output Voltage Results Diagnostic tests Part Remove jumper lead connected to Wire 4 and Wire 15BProcedure Test 4 Fixed Excitation Test Rotor Amp Draw Test Diagnostic tests Test 5 Wire Continuity 12-20 kWExample Reconnect Wire Test 7 Testing The Stator With a Vom 12-20 kWTest 6 Check Field Boost 12-20 kW Test Control Panel Wires for Continuity Repeat using stator lead WireTest 8 Test Brushless Stator Repeat using Wire Repeat using stator leadTest 9 Check Capacitor Meter lead to Wire Repeat using Wires 2Test 10 Test DPE Winding on Brushless units Measured Remove Wire 4 from the voltage regulator Test 11 Resistance Check Rotor Circuit 12-20 kWTest 12 Check Brushes And Slip Rings 12-20 kW If Continuity was measured in Steps 5 and 6 proceed to Step Test 13 Test Rotor Assembly 12-20 kW Test 14 Check AC Output Frequency Test 16 Check Stepper Motor Control V-twin Engine Units Remove air cleaner cover to access stepper motorLoosen the governor clamp bolt Figure Test 17 Check And Adjust Voltage Regulator 12-20 kW Pull ARM this Direction to Close Throttle Refer back to flow chart Test 18 Check Voltage Frequency Under LoadTest 20 Check Engine Condition Test 21 Field Flash Alternator KW Units Construction of Energizing Cord Page Transfer General Enclosure Item Description Transfer Mechanism Transfer Relay Neutral Lug Manual Transfer HandleTerminal Block Utility N1 and N2 Fuses F1, F2 Fuse HolderFuses F3 Is a schematic for a typical W/V-Type transfer switch Operational Analysis Is a wiring diagram for a typical W/V-Type transfer switch Operational analysis Utility Source Voltage Available SW1 Generator Power Available, Waiting to Transfer Utility Source Voltage Failure Transfer To Standby Transfer Action to Standby Position Generator Powering Load Utility Restored Utility Restored, Generator Still Providing Output to Load Utility Restored, Transfer Switch De-energized Utility Restored, Transfer Relay De-energized Utility Restored, Retransfer Back To Utility Utility Restored, Retransfer Back to Utility Transfer Switch In Utility Transfer Switch in Utility Introduction To Troubleshooting Troubleshooting flow charts PartProblem 7 In Automatic Mode, No Transfer to Standby Troubleshooting flow charts Problem 9 Blown F1 or F2 Fuse Check N1 & N2 Problem 11 No Battery Charge Pre-Wire Load Center Problem 12 No Battery Charge Rtsn & Rtse Transfer SwitchProblem 13 No Battery Charge GenReady Load Center Problem 14 No Battery Charge Load Shed Transfer Switch Test 26 Check Voltage at Terminal Lugs E1, E2 If the generator has been shut down, proceed as follows Test 27 Check Manual Transfer Switch Operation Manual Transfer Switch Operation Reconnect the J2 connector to the PCB Test 28 Check 23 and 15B WiringPROCEDURE/ Results Test 29 Test Transfer Relay Tr Remove the J2 connector from the circuit boardSet VOM to measure DC voltage Test 31 Check Wire Test 30 Standby Control Circuit SW1 Output Test 32 Utility Control Circuit N2A Test 33 Test Limit Switch SW2 and SW3 Test 34 Check Fuses F1 and F2 Test 36 Check N1 and N2 Voltage Test 35 Check N1 and N2 WiringReplace blown fuses as needed Test 38 Check Utility Sense Voltage Test 37 Check Utility Sensing Voltage at the Circuit BoardTest 39 Check Voltage at Terminal Lugs N1, N2 Transfer Switch Generator Test 40 Check Battery Charger Test 42 Check Wire 0 and Wire15B Pre-wire load centerMeasure across points a and C VAC should be measured Measure across points M and N VDC should be measured Test 45 Check Wire 0/15B Rtsn & Rtse Transfer Switch Rtsn & Rtse Transfer SwitchMeasure across points E and F VAC should be measured 15B Test 43, 44, and 45 Rtse Transfer Switch Test Points Test 48 Check Wire 0/15B GenReady Load Center Disconnect the J2 connector from the printed circuit board Section Measure across points C and D VAC should be measured Load Shed Transfer SwitchMeasure across points E and D VAC should be measured ATS LSSLSC Test 51 Check Wire 0 and Wire 15B Load Shed Transfer Switch Part DC Control Auto-Off-Manual Switch Description and components PartTerminal Strip / Interconnection Circuit Board Description and components Amp Fuse KW Printed Circuit Boards and J1 Connector J2 Connector PCB END J1 Connector Stepper Motor Harness END Remote Wireless Connection Harness END Remote Wireless Connection N1/N2 Connector PCB END Harness END 17 and 20 kW Printed Circuit Board and J1 Connector Choke Solenoid Connector Pin Number Identification Menu System Navigation Description Components Stator Circuit Condition Utility Source Voltage Available Initial Dropout of Utility Source Voltage Circuit Condition Initial Dropout of Utility Source Voltage Utility Voltage Dropout and Engine Cranking Circuit Condition Engine Cranking Engine Startup and Running Circuit Condition Engine Startup and Running Initial Transfer to the Standby Source Circuit Condition Initial Transfer to Standby Utility Voltage Restored / Re-transfer to Utility Circuit Condition Utility Voltage Restored Engine Shutdown Circuit Condition Retransfer to Utility and Engine Shutdown Controller Switch BAD Replace Controller Assembly Problem 17 Engine Cranks but Won’t Start Readjust Replace Choke Solenoid BAD Problem 19 Shutdown Alarm/Fault Occured Problem 21 Generator Will Not Exercise Problem 20 7.5 Amp Fuse F1 BlownProblem 22 No Low Speed Exercise Test 58 Auto-Off-Manual Switch Twin Only Test 56 Check Position Of Auto-Off Manual SwitchTest 57 Try a Manual Start Test 59 Test Auto Operations Test 61 Check BatteryTest 60 Check 7.5 Amp Fuse Test Battery Condition Typical Battery Load Tester Test 62 Check Wire 56 Voltage If battery voltage is indicated in refer back to flow chartTest 63 Test Starter Contactor Relay V-twin Only Set a VOM to measure DC voltage Reconnect Wire 13 to the SCR Test 64 Test Starter Contactor Single Cylinder Engine Test 65 Test Starter Motor Shorted, open or grounded armatureChecking the Pinion Pinion Pinion Tools for Starter Performance Test Port Test 66 Check Fuel Supply PressureSolenoid Removed Test 67 Check Circuit Board Wire Output 12-20 kW Gas Pressure Test point Test 68 Check Fuel Solenoid Disconnect the C3 ConnectorTest 69 Check Choke Solenoid Approximately 3.7 ohms should be measured Solenoid De-Energized, Choke Closed KW Units Disconnect C3 Connector Set a VOM to measure resistance Disconnect the C3 Connector Set a VOM to measure DC voltageTest 70 Check for Ignition Spark KW Choke Solenoid Test 71 Check Spark Plugs Test 73 Check Shutdown Wire Remove a spark plugRepeat Steps 1 through 8 on remaining cylinder Check Compression Test 74 Check and Adjust Ignition Magnetos Depending on engine type, do the following Setting Ignition Magneto Armature Air Gap Magneto Cylinder One Back, Short Test 75 Check Oil Pressure Switch Wire Navigate to the Digital inputs display screenCheck engine crankcase oil level With oil level correct, try starting the engine Test 76 Check High Oil Temperature Switch Test 77 Check and Adjust ValvesReplace switch if it fails the test Remove the High Oil Temperature Switch Set the AUTO-OFF-MANUAL switch to the Manual position Test 78 Check Wire 18 ContinuityBall Stud JAM NUT Test 80 Check Cranking and Running Circuits Test 79 Test Exercise FunctionRecord the current date and time of the unit Choke Solenoid 8kW Test 81 Check to see if Low Speed Function is enabled Disconnect Wire 4 and Wire 0 from the Voltage Regulator VRTest 82 Check operation Choke Solenoid If the solenoid closed, replace the controller Part Operational Tests Manual Transfer Switch Operation System functional tests PartElectrical Checks Set the generator main line circuit breaker to OFF or open System functional tests Generator Tests Under Load Verify that the AUTO-OFF-MANUAL switch is set to Auto Setting The Exercise TimerChecking Automatic Operation Part Disassembly Front Engine Access Major Disassembly PartRemove control harnesses Major Disassembly Section Section Major Disassembly Section Section Section Section Engine mount nuts with ground wires. See Figure Torque Requirements Unless Otherwise Specified Part Electrical Data Wiring Diagram, 8 kW Home Standby Part Drawing #0G7945 Wiring Diagram, 8 kW Home Standby Schematic, 8 kW Home Standby Part Drawing #0G8511 Part Schematic, 8 kW Home Standby Wiring Diagram, 10 kW Home Standby Part Drawing #0G7946 Part Wiring Diagram, 10 kW Home Standby Schematic, 10 kW Home Standby Part Drawing #0G8512 Part Schematic, 10 kW Home Standby Wiring Diagram, 14 kW Home Standby Part Drawing #0G7947 Part Wiring Diagram, 14 kW Home Standby Schematic, 14 kW Home Standby Part Drawing #0G8513 Part Schematic, 14 kW Home Standby Wiring Diagram, 17 kW Home Standby Part Drawing #0G7948 Part Wiring Diagram, 17 kW Home Standby Schematic, 17 kW Home Standby Part Drawing #0G8514 Part Schematic, 17 kW Home Standby Wiring Diagram, 20 kW Home Standby Part Drawing #0G8186 Part Wiring Diagram, 20 kW Home Standby Schematic, 20 kW Home Standby Part Drawing #0G8515 Part Schematic, 20 kW Home Standby Transfer Switch, 9/10/12/16 circuit Wiring Diagram, Home Standby Part Wiring Diagram, Home Standby Schematic, Home Standby Drawing #0G7959Page Page Page MyGenerac.com