Models: 4389, 4758 (6 kW NG, 7 kW LP) 4456, 4759 (12 kW NG, 12 kW LP) 4390, 4760 (13 kW, 15 kW LP) DIAGNOSTIC REPAIR MANUAL AUTOMATIC HOME STANDBY GENERATORS Visit us online at www.guardiangenerators.com DIAGNOSTIC REPAIR MANUAL AIR-COOLED PART TITLE Specifications 1 General Information 2 AC Generators 3 V-Type Prepackaged Transfer Switches 4 DC Control 5 Operational Tests and Adjustments 6 Electrical Data DIAGNOSTIC REPAIR MANUAL Air-cooled, Prepackaged Automatic Standby Generators Models: 04389, 04758 (6 kW NG, 7 kW LP) 04456, 04759 (12 kW NG, 12 kW LP) 04390, 04760 (13 kW NG, 15 kW LP) TABLE OF CONTENTS Page 1 TO FIND KNOWN VALUES 1-PHASE 3-PHASE KILOWATTS (kW) Volts, Current, Power Factor E x I E x I x 1.73 x PF 1000 1000 KVA Volts, Current E x I E x I x 1.73 1000 1000 AMPERES kW, Volts, Power Factor kW x 1000 kW x 1000 E E x 1.73 x PF WATTS Volts, Amps, Power Factor Volts x Amps E x I x 1.73 x PF NO. OF ROTOR Frequency, RPM 2 x 60 x Frequency 2 x 60 x frequency POLES RPM RPM FREQUENCY RPM, No. of Rotor Poles RPM x Poles RPM x Poles 2 x 60 2 x 60 RPM Frequency, No. of Rotor Poles 2 x 60 x Frequency 2 x 60 x Frequency Rotor Poles Rotor Poles kW (required for Motor Horsepower, Efficiency HP x 0.746 HP x 0.746 Motor) Efficiency Efficiency RESISTANCE Volts, Amperes E E II VOLTS Ohm, Amperes I x R I x R AMPERES Ohms, Volts E E RR E = VOLTS I = AMPERES R = RESISTANCE (OHMS) PF = POWER FACTOR ELECTRICAL FORMULAS Page 2 SPECIFICATIONS Page 3 GENERATOR Models 04389, 04758 Models 04456, 04759 Model 04390, 04760 Rated Max. Continuous Power Capacity (Watts*) 6,000 NG/7,000 LP 12,000 NG/12,000 LP 13,000 NG/15,000 LP† Rated Voltage 120/240 120/240 120/240 Rated Max. Continuous Load Current (Amps) 120 Volts** 50.0 NG/58.3 LP 100.0 NG/100.0 LP 108.3 NG/125.0 LP 240 Volts 25.0 NG/29.2 LP 50.0 NG/50.0 LP 54.2 NG/62.5 LP Main Line Circuit Breaker 30 Amp 50 Amp 60 Amp/70 Amp† Phase 1 1 1 Number of Rotor Poles 2 2 2 Rated AC Frequency 60 Hz 60 Hz 60 Hz Power Factor 1 1 1 Battery Requirement Group 26/26R Group 26/26R Group 26/26R 12 Volts and 12 Volts and 12 Volts and 350 Cold-cranking 550 Cold-cranking 550 Cold-cranking Amperes Minimum Amperes Minimum Amperes Minimum Weight 452 Pounds 470 Pounds 487 Pounds Output Sound Level @ 23 ft (7m) at full load 68 db (A) 70.5db (A) 71.5 db (A) Normal Operating Range -20°F (-28.8°C) to 104°F (40°C) * Maximum wattage and current are subject to and limited by such factors as fuel Btu content, ambient temperature, altitude, engine power and condition, etc. Maximum power decreas- es about 3.5 percent for each 1,000 feet above sea level; and also will decrease about 1 percent for each 6° C (10° F) above 16° C (60° F) ambient temperature. ** Load current values shown for 120 volts are maximum TOTAL values for two separate circuits. The maximum current in each circuit must not exceed the value stated for 240 volts. † 15,000 watt with upgrade kit 04578-0. Kit includes power harnesses and 70 amp 2-pole circuit breaker. ENGINE Models 04389, 04758 Models 04456, 04759 Models 04390, 04760 Type of Engine GH-410 GT-990 GT-990 Number of Cylinders 1 2 2 Rated Horsepower 14.5 @ 3,600 rpm 26 @ 3,600 rpm 30 @ 3,600 rpm Displacement 410cc 992cc 992cc Cylinder Block Aluminum w/Cast Aluminum w/Cast Aluminum w/Cast Iron Sleeve Iron Sleeve Iron Sleeve Valve Arrangement Overhead Valves Overhead Valves Overhead Valves Ignition System Solid-state w/Magneto Solid-state w/Magneto Solid-state w/Magneto Recommended Spark Plug RC12YC RC12YC RC12YC Spark Plug Gap 0.76 mm (0.030 inch) 0.5 mm (0.020 inch) 0.5 mm (0.020 inch) Compression Ratio 8.6:1 9.5:1 9.5:1 Starter 12 VDC 12 VDC 12 VDC Oil Capacity Including Filter Approx. 1.5 Qts Approx. 1.7 Qts Approx. 1.7 Qts Recommended Oil Filter Generac Part # 070185 Generac Part # 070185 Generac Part # 070185 Recommended Air Filter Generac Part # 0C8127 Generac Part # 0C8127 Generac Part # 0C8127 Operating RPM 3,600 3,600 3,600 FUEL CONSUMPTION Model # Natural Gas* LP Vapor** 1/2 Load Full Load 1/2 Load Full Load 04389, 04758 74 105 0.91/33 1.21/44.1 04556, 04759 114 185 1.34/48.9 2.17/79.0 04390, 04760 148.5 240 1.73/63.2 2.80/102.3 * Natural gas is in cubic feet per hour. **LP is in gallons per hour/cubic feet per hour. STATOR WINDING RESISTANCE VALUES / ROTOR RESISTANCE Model 04692 Models 04389 Models 04456 Models 04390 04679, 04758 04759 04760 Power Winding: Across 11 & 22 0.190-0.208 ohms 0.223-0.259 ohms 0.115 ohms 0.08/0.08 ohms Power Winding: Across 33 & 44 0.190-0.208 ohms 0.223-0.259 ohms 0.115 ohms 0.08/0.08 ohms Excitation Winding: Across 2 & 6 1.442-1.670 ohms 1.53-1.77 ohms 0.745 ohms 0.705 ohms Engine Run Winding: Across 55 & 66A 0.104-0.120 ohms 0.100-0.169 ohms 0.109 ohms 0.087 ohms Battery Charge Winding: Across 66 & 77 0.137-0.158 ohms 0.146-0.169 ohms 0.164 ohms 0.130 ohms Rotor Resistance 15.42-17-85 ohms 11.88-13.76 ohms 15.9 ohms 19.8 ohms Page 4 SPECIFICATIONS LEFT S IDE VIE W TRAN S FER S WIT CH FR O NT VIE W ( IF SUPPLIED ) "D O N O T LIFT BY THE R OO F " LIFTIN G H O LE S 4- CO RNER S Ø 30 .2mm [ Ø 1.19" ] **ALL DIMEN S I O N S IN : MILLIMETERS [ INCHES ] 76.2mm [ 3.00" ] PEA G RAVE L MIN U M UM 716 [2 604 [ 23.5" ] 1193 [ 47" ] 308 [ 12" ] 74 3 [ 29.25" ] 207 [ 8.14" ] 7 04 [ 27.7" ] 622 [ 24.5" ] 1232 [ 48.5" ] H O ME S TANDBY G ENERAT OR IN S TALLATI O N DIA G RA M 0 D 3 7 39 MOUNTING DIMENSIONS Page 5 SPECIFICATIONS REAR VIEW RI G HT S IDE VIE W AIR OU T L AIR INTAKE G R OU NDIN G L UG 3/ 4" NPT F U EL INLE T G A S PRE SSU RE O F 11-14 " WATER COLUMN RE Q UIRE D **ALL DIMEN S I O N S IN : MILLIMETERS [ INCHES ] 914mm [ 36.0" ] MINIM U M O PEN ARE A ALL AR OU ND U NI T 260 [ 10.2" ] 14 9 [ 5.9" ] 1172.3 [ 46.2" ] 490.7 [ 19.3" ] C ABLE A CC E SS H O LE S. ( REMOVE PLUG FOR ACCESS ) H O ME S TANDBY G ENERAT OR IN S TALLATI O N DIA G RA M MOUNTING DIMENSIONS SPECIFICATIONS Page 6 MAJOR FEATURES CONTROL PANEL BATTERY COMPARTMENT FUEL REGULATOR AIR FILTER EXHAUST ENCLOSURE OIL FILTER DATA DECAL (BEHIND BATTERY COMPARTMENT) CONTROL PA N E L AIR FILTER EXHAUST ENCLOSURE BATTERY COMPARTMENT FUEL REGULATOR OIL FILTER OIL DIPSTICK DATA DECAL (BEHIND BATTERY COMPARTMENT) 12 kW and 15 kW, V-twin GT-990 Engine 7 kW, Single Cylinder GH-410 Engine PART TITLE 1.1 Generator Identification 1.2 Prepackaged Installation Basics 1.3 Preparation Before Use 1.4 Testing, Cleaning and Drying 1.5 Engine-Generator Protective Devices 1.6 Operating Instructions 1.7 Automatic Operating Parameters PART 1 GENERAL INFORMATION Air-cooled, Prepackaged Automatic Standby Generators Models: 04389, 04758 (6 kW NG, 7 kW LP) 04456, 04759 (12 kW NG, 12 kW LP) 04390, 04760 (13 kW NG, 15 kW LP) TABLE OF CONTENTS Page 7 INTRODUCTION This Diagnostic Repair Manual has been prepared especially for the purpose of familiarizing service per- sonnel with the testing, troubleshooting and repair of air-cooled, prepackaged automatic standby genera- tors. Every effort has been expended to ensure that information and instructions in the manual are both accurate and current. However, Generac reserves the right to change, alter or otherwise improve the prod- uct at any time without prior notification. The manual has been divided into ten PARTS. Each PART has been divided into SECTIONS. Each SEC- TION consists of two or more SUBSECTIONS. It is not our intent to provide detailed disassembly and reassemble instructions in this manual. It is our intent to (a) provide the service technician with an under- standing of how the various assemblies and systems work, (b) assist the technician in finding the cause of malfunctions, and (c) effect the expeditious repair of the equipment. ITEM NUMBER: Many home standby generators are manufactured to the unique specifications of the buyer. The Model Number identifies the specific generator set and its unique design specifications. SERIAL NUMBER: Used for warranty tracking purposes. Figure 1. A Typical Data Plate Item # 0055555 1234567 120/240 AC 125/62.5 15000 Serial Volts Watts 1 PH, 60 HZ, RPM 3600 NEUTRAL FLOATING CLASS F INSULATION MAX OPERATING AMBIENT TEMP - 120F/49C FOR STANDBY SERVICE MAX LOAD UNBALANCED - 50% GENERAC POWER SYSTEMS WAUKESHA, WI MADE IN U.S.A. Amps Page 8 PART 1 GENERAL INFORMATION SECTION 1.1 GENERATOR IDENTIFICATION . kW, 15 kW LP) DIAGNOSTIC REPAIR MANUAL AUTOMATIC HOME STANDBY GENERATORS Visit us online at www.guardiangenerators.com DIAGNOSTIC REPAIR MANUAL AIR-COOLED PART TITLE Specifications 1 General