Generac Power Systems 20 kW LP, 10 kW LP, 13 kW NG, 7 kW NG, 9 kW NG

Section 4.2

Operational analysis

Part 4

DC control

Utility Voltage Restored / Re-transfer to Utility

The “Load” is powered by the standby power supply. The circuit board continues to seek an acceptable utility source voltage. On restoration of utility source voltage, the following events will occur:

•On restoration of utility source voltage above 75 percent of the nominal rated voltage, a “retransfer time delay” on the circuit board starts timing. The timer will run for about fifteen (15) seconds.

•At the end of fifteen (15) seconds, the “retransfer time delay” will stop timing and circuit board action will open the Wire 23 circuit to ground. The transfer relay (TR) will then de-energize.

•When the transfer relay (TR) de-energizes, its normally-closed contacts close. Utility source voltage is then delivered to the utility closing coil (C1), via Wires N1A/N2A, the closed TR contacts, Wire 126, limit switch XA1, and a bridge rectifier.

		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 20 kW LP, 10 kW LP, 13 kW NG, 7 kW NG, 9 kW NG manual Utility Voltage Restored / Re-transfer to Utility

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 Resistance Testing, cleaning and drying PartMeasuring Current Volts Amps Ohms Electrical UnitsOhm’s Law Visual Inspection Insulation ResistanceMegohmmeter ONE 1 Second Stator Insulation Resistance Test 10 kW Repeat between Wire 2 and Stator LeadStator Insulation Resistance Test 12-20 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 AC Generator Rotor AssemblyEngine-Generator Drive System 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 4 Generator Produces High Voltage at No-Load Troubleshooting flowchartsProblem 3 Generator Produces Low 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 Example Test 5 Wire Continuity 12-20 kWDiagnostic tests Test 6 Check Field Boost 12-20 kW Test 7 Testing The Stator With a Vom 12-20 kWReconnect Wire Test 8 Test Brushless Stator Repeat using stator lead WireTest Control Panel Wires for Continuity Test 9 Check Capacitor Repeat using stator leadRepeat using Wire 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 Loosen the governor clamp bolt Figure Remove air cleaner cover to access stepper motorTest 16 Check Stepper Motor Control V-twin Engine Units 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 F3 Fuse HolderFuses F1, F2 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 Problem 7 In Automatic Mode, No Transfer to Standby Troubleshooting flow charts PartIntroduction To Troubleshooting 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 PROCEDURE/ Results Test 28 Check 23 and 15B WiringReconnect the J2 connector to the PCB Set VOM to measure DC voltage Remove the J2 connector from the circuit boardTest 29 Test Transfer Relay Tr 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 Replace blown fuses as needed Test 35 Check N1 and N2 WiringTest 36 Check N1 and N2 Voltage Test 39 Check Voltage at Terminal Lugs N1, N2 Test 37 Check Utility Sensing Voltage at the Circuit BoardTest 38 Check Utility Sense Voltage 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 Measure across points E and F VAC should be measured Rtsn & Rtse Transfer SwitchTest 45 Check Wire 0/15B Rtsn & Rtse Transfer Switch 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 E and D VAC should be measured Load Shed Transfer SwitchMeasure across points C and D VAC should be measured LSC LSSATS 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 22 No Low Speed Exercise Problem 20 7.5 Amp Fuse F1 BlownProblem 21 Generator Will Not Exercise Test 57 Try a Manual Start Test 56 Check Position Of Auto-Off Manual SwitchTest 58 Auto-Off-Manual Switch Twin Only Test 60 Check 7.5 Amp Fuse Test 61 Check BatteryTest 59 Test Auto Operations 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 Solenoid Removed Test 66 Check Fuel Supply PressurePort Test 67 Check Circuit Board Wire Output 12-20 kW Gas Pressure Test point Test 69 Check Choke Solenoid Disconnect the C3 ConnectorTest 68 Check Fuel Solenoid Approximately 3.7 ohms should be measured Solenoid De-Energized, Choke Closed KW Units Test 70 Check for Ignition Spark Disconnect the C3 Connector Set a VOM to measure DC voltageDisconnect C3 Connector Set a VOM to measure resistance 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 Ball Stud JAM NUT Test 78 Check Wire 18 ContinuitySet the AUTO-OFF-MANUAL switch to the Manual position Record the current date and time of the unit Test 79 Test Exercise FunctionTest 80 Check Cranking and Running Circuits 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 Checking Automatic Operation Setting The Exercise TimerVerify that the AUTO-OFF-MANUAL switch is set to Auto Part Disassembly Remove control harnesses Major Disassembly PartFront Engine Access 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