113091 042793 OPERATION AND MAINTENANCE MANUAL with ILLUSTRATED PARTS LIST for ENGINE-DRIVEN GENERATOR SET SPECIFICATION NUMBERS 6919A and 6919B For Truck or Trailer Mounting MODEL No. 90J20 90-KVA, 400-HZ, 115/200-V AC, 3-PHASE with JOHN DEERE DIESEL ENGINE TYPE 6059TL (Turbocharged) Hobart Brothers Company Airport Systems Group Ground Power Equipment Troy, Ohio 45373 U.S.A.
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INTRODUCTION This manual contains operation and maintenance information for four series of 400-Hertz generator sets manufactured by Hobart Brothers Company, Power Systems Group, Troy, Ohio 45373. This manual is not intended to be a textbook on electricity or electronics. Its primary purpose is to provide information and instructions to experienced operators, electricians, and mechanics who have never seen or operated this equipment. It is the intent of this manual to guide and assist operators and maintenance people in the proper use and care of the equipment. Use of the manual should not be put off until a trouble or need for help develops. Read the instructions before starting the unit. Learn to use the manual and to locate information contained in it. Its style and arrangement are very similar to commercial aircraft manuals. The manual is divided into six chapters. Each chapter is divided into as many sections as required. Each new section starts with page 1. Each page is identified by chapter, section and page number, which are located in the lower, outside corner. When information located in another portion of the manual is referred to, its location is identified by a chapter, section, and paragraph, or figure number. For example, (See 2-3, Para. B) refers to information located in Chapter 2, Section 3, Paragraph B. If a Chapter and Section are not indicated in a reference, the referenced material is located in the same section as the reference, Example, (See Para. B). In addition to operation and maintenance instructions, the manual contains an illustrated parts list in Chapter 4, and a collection of manufacturer s literature and supplemental information in Chapter 6. Content of the manual is arranged as follows: Chapter 1. Description/Operation Chapter 2. Servicing Chapter 3. Troubleshooting Chapter 4. Illustrated Parts List Chapter 5. Optional Equipment Chapter 6. Manufacturer s Literature November 30/91 Introduction Page 1
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Table of Contents SUBJECT CHAPTER/SECTION PAGE WARNING INTRODUCTION Chapter 1. Description/Operation Section 1. Description 1-1 1 1. General 1-1 1 2. Orientation 1-1 1 3. Special Features 1-1 1 A. Protective Monitor 1-1 1 B. Voltage Regulator 1-1 2 C. Electric Governor 1-1 2 4. Canopy 1-1 2 5. Optional Equipment 1-1 2 6. Engine, Generator, and Controls Assembly 1-1 2 A. Basic Engine 1-1 2 B. Engine Manufacturer s Equipment 1-1 2 C.Hobart Engine Equipment 1-1 5 (1) Electric governor system 1-1 5 (a) Magnetic pickup 1-1 5 (b) Control unit 1-1 5 (c) Actuator 1-1 5 (2) Engine electrical system 1-1 5 (3) Engine protective devices 1-1 5 (a) High coolant temperature switch 1-1 5 (b) Oil pressure switch 1-1 5 (4) Air cleaner 1-1 7 (5) Exhaust system 1-1 7 (6) Radiator 1-1 7 D. Generator 1-1 8 E. Control Box Assembly 1-1 9 (1) Front Panel 1-1 9 (a) Generator output monitors (meters) 1-1 9 (b) Meter and line switches 1-1 9 (c) Instrument light 1-1 9 (d) Indicating lights 1-1 9 (2) Control box internal components 1-1 11 (a) Sensing modules 1-1 11 (b) Memory and time delay module 1-1 11 (c) Excitation-deenergization relay 1-1 11 (d) Plug-interlock relay 1-1 12 (e) Test-bank switch 1-1 12 (f) Resistor 1-1 12 November 30/91 Table of Contents Page 1
SUBJECT CHAPTER/SECTION PAGE (g) Fuse-interlock relay 1-1 12 (h) Auxiliary underfrequency relay 1-1 12 (j ) Terminal boards 1-1 12 (k) Solid-state voltage regulator 1-1 12 (l) Overload module 1-1 12 (m) Rectifier 1-1 12 F. Engine Control Panel (See Fig. 8) 1-1 14 (1) Engine instruments 1-1 14 (a) Ammeter 1-1 14 (b) Temperature gage 1-1 14 (c) Oil pressure gage and oil pressure switch 1-1 14 (d) Hourmeter 1-1 14 (e) Fuel gage and blocking diodes 1-1 14 (2) Engine and generator controls 1-1 15 (a) Engine-generator control switch 1-1 15 (b) Contactor control switch 1-1 15 (c) Instrument light and switch 1-1 15 (d) Engine starting circuit 1-1 15 (e) Indicating lights 1-1 15 (f) Fuse 1-1 15 G. Load Contactor Circuit Components 1-1 17 (1) Load contactor 1-1 17 (2) Current transformers 1-1 17 (a) Ammeter current transformers 1-1 17 (b) Line-drop current transformers 1-1 17 (c) Overload current transformers 1-1 17 (3) Overload module 1-1 17 (4) Rectifier 1-1 18 Section 2. Preparation For Use, Storage, Or Shipping 1-2 1 1. Preparation for Use 1-2 1 A. Inspection/Check Inspect the unit thoroughly prior to operation. 1-2 1 B. Installing Three-phase AC Output Cables 1-2 1 2. Preparation for Storage 1-2 2 A. General 1-2 2 B. Temporary Storage When storing the unit for 30 days or less, prepare as follows: 1-2 2 C. Long Time Storage (Over 30 Days) 1-2 3 Section 3. Operation 1-3 1 1. General 1-3 1 2. Operating the Generator Set 1-3 1 A. Pre-start Inspection 1-3 1 B. Normal Engine Starting Procedures 1-3 1 C.Preparation for Power Delivery 1-3 3 D. Power Delivery 1-3 4 E. Discontinue Power Delivery 1-3 4 F. Stopping the Engine 1-3 4 Table of Contents November 30/91 Page 2
SUBJECT CHAPTER/SECTION PAGE 3. Trailer Operation 1-3 5 A. Towing 1-3 5 B. Parking 1-3 5 Chapter 2. Service Section 1. Maintenance 2-1 1 1. General 2-1 1 2. Inspection 2-1 1 3. Lubrication 2-1 1 A. General 2-1 1 B. Generator 2-1 1 C. Generator Controls 2-1 1 D. Engine 2-1 1 (1) Lubrication schedule 2-1 2 (2) Oil specification 2-1 2 (3) Oil viscosity 2-1 2 (4) Changing engine oil 2-1 2 (5) Changing engine oil filter 2-1 2 E. Starter 2-1 2 F. Trailer 2-1 2 (1) Front axle assembly 2-1 2 (2) Wheel bearings 2-1 3 4. Air Cleaner Service 2-1 3 A. Inspecting the Air Cleaner 2-1 3 B. Cleaning Instructions 2-1 3 C. Disposal 2-1 4 5. Engine Fuel 2-1 4 A. Quality 2-1 4 B. Fuel Filter 2-1 4 6. Engine Cooling System 2-1 4 A. General 2-1 4 B. Radiator Cap 2-1 4 (1) General 2-1 4 (2) Removal 2-1 5 (3) Installation 2-1 5 C. Warm Weather Operation 2-1 5 D. Cold Weather Operation 2-1 5 (1) General 2-1 5 (2) Checking coolant solution 2-1 5 (3) Preparing the coolant solution 2-1 5 (4) Installing the antifreeze solution 2-1 6 E. Draining the Cooling System 2-1 6 F. Cleaning the Cooling System 2-1 7 G. Cleaning the Radiator Core 2-1 7 H. Filling the Cooling System 2-1 7 November 30/91 Table of Contents Page 3
SUBJECT CHAPTER/SECTION PAGE 7. Generator Maintenance 2-1 8 A. Cleaning 2-1 8 B. Adjustment 2-1 8 8. Drive Belts 2-1 8 A. Checking Belt Tension 2-1 8 B. Belt Adjustment 2-1 8 9. Battery Maintenance 2-1 8 A. General 2-1 8 B. Battery Location and Accessibility 2-1 8 C. Battery Care 2-1 9 D. Liquid Level 2-1 9 E. Cleaning the Battery 2-1 9 F.Testing the Battery 2-1 9 (1) Test with Battery-Starter Tester 2-1 9 (2) Test with Hydrometer 2-1 10 10. Service Helps 2-1 10 A. Wiring 2-1 10 B. Generator Exciter 2-1 10 (1) Preparation for exciter removal. 2-1 10 (2) Exciter removal 2-1 10 (3) Exciter installation 2-1 10 SECTION 2. INSPECTION/CHECK 2-2 1 1. General 2-2 1 2. Engine 2-2 1 A. Fuel 2-2 1 B. Lubrication 2-2 1 C. Coolant 2-2 1 D. V-Belt 2-2 1 E. Exhaust System 2-2 1 3. Electrical System (12-V DC) 2-2 3 A. Lights 2-2 3 B. Fuses 2-2 3 C. Wiring and Connections 2-2 4 4. Electrical System (115-V AC) 2-2 4 A. Monitoring Instruments 2-2 4 B. Indicating Lights 2-2 4 C. Protective Modules 2-2 4 D. Wiring and Connections 2-2 4 5. Trailer 2-2 4 Section 3. Adjustment/Test 2-3 1 1. General 2-3 1 2. Generator Set Test 2-3 1 A. Pre-operational Test Procedures 2-3 1 B. Operational Test Procedures 2-3 2 Table of Contents November 30/91 Page 4
SUBJECT CHAPTER/SECTION PAGE 3. Generator Set Adjustment 2-3 7 A. Generator Adjustment 2-3 7 B. Voltage Regulator Adjustments 2-3 7 C.Basic Engine Adjustments 2-3 7 D. Engine Accessories Adjustment 2-3 7 (1) Generator and fan belt adjustment 2-3 7 E. Electric Governor System Adjustment 2-3 8 (1) Actuator linkage adjustment 2-3 8 (2) Magnetic pickup adjustment 2-3 9 (a) Preliminary Controller Settings 2-3 10 (b) Checking No-Load Operation of Controller 2-3 11 (c) Checking Operation of Controller Under Load 11 (a) Preliminary Controller Settings 2-3 11 (b) Checking No-Load Operation of Controller 2-3 13 (c) Adjusting for RATED Speed Operation 2-3 13 (d) Checking the Actuator 2-3 13 (e) Checking Operation of Controller Under Load 13 (5) Checking Magnetic Pick-up signal 2-3 15 4. Generator and Exciter Test 2-3 15 5. Diode Test 2-3 16 Chapter 3. Troubleshooting Section 1. Troubleshooting Procedures 3-1 1 1. General 3-1 1 2. Trouble Shooting Chart (Figure 5) 3-1 1 A. Description 3-1 1 B. Use of the Trouble Shooting Chart 3-1 1 3. Equipment for Troubleshooting 3-1 2 4. Safety - WARNING: 3-1 2 5. Parts Replacement 3-1 2 6. Test Values 3-1 2 7. Checking Connections and Leads 3-1 3 8. Electric Governor Trouble Shooting 3-1 3 9. Engine Trouble Shooting Procedures 3-1 3 10.Illustrations 3-1 3 Chapter 4. Illustrated Parts List Section 1. Introduction 4-1 1 1. General 4-1 1 2. Purpose 4-1 1 3. Arrangement 4-1 1 4. Explanation of Parts List 4-1 1 November 30/91 Table of Contents Page 5
SUBJECT CHAPTER/SECTION PAGE A. Contents 4-1 1 B. Parts List Form 4-1 2 (1) FIGURE-ITEM NO. Column 4-1 2 (2) HOBART PART NUMBER Column 4-1 2 (3) NOMENCLATURE Column 4-1 2 (4) REC. SPARES Column 4-1 2 (5) EFF (Effective) Column 4-1 2 (6) UNITS PER ASSEMBLY Column 4-1 2 Section 2. Manufacturer s Codes 4-2 1 1. Explanation of Manufacturer s (Vendor) Code List 4-2 1 Section 3. Parts List 4-3 1 1. Explanation of Parts List Arrangement 4-3 1 2. Symbols and Abbreviations 4-3 1 1. Explanation of Numerical Index 4-3 1 Section 4. Numerical Index 1. Explanation of Numerical Index 4-4 1 Chapter5.OptionalEquipment Chapter 6. Manufacturer s Literature Unusual Service Conditions Table of Contents November 30/91 Page 6
Chapter 1. Description/Operation Section 1. Description 1. General This manual covers two series of trailer-mounted 90-kVA generator sets manufactured by Hobart Brothers Company: Specification No. 6919A and Specification No. 6919B. Generator sets in Series 6919A feature an armature with Hoover Bearings, Browning Coupler, and different magnetic pole construction for the generator revolving field. This new armature can be easily identified by the two copper rings on each end of the field coils and copper wedges between the magnetic poles. Series 6919A generator sets also feature a wide-type single bearing on the generator. Generator sets in Series 6919B are virtually identical to Generator sets in Series 6919A, except that the engine has an improved fuel pump and a dual speed governing system for adjustment of idle speed and rated speed. The purpose of the generator set (Fig. 1) is to generate and deliver regulated, 400-Hz electrical power to a parked (or towed) aircraft for operation of the aircraft s electrical equipment when the on-board generators are not running. See Figure 2 for specifications and capabilities. Within a particular series, the basic generator set - including the engine, generator and all controls - is identical for all units in the series. However, within a particular series different variations of the basic generator set are offered. Each variation is identified by a specification number, which is derived by adding a dash number (-1, -2, etc.) suffix is to the Series number. The specification number generally indicates the manner in which the particular individual unit is mounted, and it may also indicate some other special feature of the unit. Identification of different specifications within each series will be explained later in the Description. Generally, information and instructions throughout the manual apply to all specifications. Information which applies only to a certain specification will be qualified and identified as such. 2. Orientation For purpose of orientation and to familiarize operators and maintenance personnel with the location of components, the radiator is considered to be at the FRONT of the unit. The generator and controls are at the REAR. RIGHT and LEFT are determined by standing at the rear end facing the machine. 3. Special Features The generator set has many special features which are later described more fully under the assemblies in which they appear. Some of the main features are mentioned here and described briefly. A. Protective Monitor A single, solid-state device (7, Fig. 7) receives signals from all of the fault sensing units in the generator output circuit and functions to cause the load to be disconnected from the generator if an abnormal condition of voltage, frequency, or load develops. November 30/91 1-1 Page 1
B. Voltage Regulator A solid-state, adjustable voltage regulator (Items 13 and 17, Fig. 7) provides automatic voltage regulation at the aircraft (or distribution panel when applicable). The regulator is also adjustable for a variety of output cable sizes and lengths. C. Electric Governor 4. Canopy The engine is equipped with an all electric type governor kit (13 and 16, Fig. 3) and other special equipment more fully described under the engine description. A sheet metal enclosure, identified as a canopy (2, Fig. 1), provides protection for the engine, generator and electrical controls. This generator set is equipped with a canopy having doors on both sides. This canopy is largely of one-piece construction, with the four access doors of the unit attached to the canopy top by welded-on piano hinges. Hex-head bolts attach the front and back panels to the canopy top assembly and the frame. Air enters the bottom of the unit into the engine compartment and is discharged through the radiator by the engine fan. Metal strips are mounted horizontally across the front grille to deflect engine fan exhaust air and noise downward. Air entering the generator compartment is circulated over generator controls and drawn into the rear exciter and generator housings where it passes over all windings before being discharged by the generator fan. Panel mounted instruments may be observed through two Plexiglas windows in the left rear door which covers the control box and engine control panel. The lower window is slanted outward at the bottom to provide access to engine controls when the door is closed. Doors on the unit are equipped with flexible rubber draw latches (9, Fig. 1) which prevent excessive door vibration when the unit is running. 5. Optional Equipment Three items of optional equipment are presently available for units covered by this manual: A coldweather starting aid kit identified as Hobart Part No. 180961, a four-wheel trailer with fuel tank, identified as Hobart Part No. 281056, and a second output assembly, identified as Hobart Part No. 281286-1. 6. Engine, Generator, and Controls Assembly This assembly is the basic generator set without canopy. It includes all components required to generate and regulate 400 Hz, 115/200 V, threephase power, and is operable when provided with fuel and 12 V DC power. The engine-generator assembly is mounted on a welded steel frame. A superstructure, attached to the main frame, provides mounting facilities for the canopy, control box, and electrical equipment and controls. A. Basic Engine This generator set is equipped with a 6-cylinder, in-line, turbocharged John Deere engine. See Figure 2 for general specifications, and see Engine Operator s Handbook in Chapter 6 for more detailed information. B. Engine Manufacturer s Equipment As received from the engine manufacturer, the engine includes the following equipment which is described in the John Deere shop Manual (Chap. 6) (1) Fuel filter. (2) Reverse-flow, engine cooling fan to blow air OUTWARD through the radiator. 1-1 November 30/91 Page 2
1. Engine fan exhaust deflectors 6. Generator control panel window 2. Radiator cap access hole 7. Engine control panel window 3. Canopy 8. Mounting frame 4. Doors (attached to canopy) 9. Door latches 5. Engine exhaust pipe and cover Generator Set (Basic Unit) Figure 1 November 30/91 1-1 Page 3
PHYSICAL BASIC GENERATOR SET Length overall Width Height Weight (Approximate) TRAILER-MOUNTED GENERATOR SET Length overall Width Height Weight (Approximate) 84 inches (2134 mm) 33 inches (838 mm) 43 inches (1092 mm) 3655 pounds (1658 kg) 90 inches (2286 mm) 66 inches (1676 mm) 57 inches (1448 mm) 4120 pounds (1868.5 kg) GENERATOR Output power rating 90 KVA Output voltage 115/200 V Rated load capacity 260 A Frequency (cycles-per-second) 400 Hz Output kilowatts 72 KW Power factor 0.8 PF Duty cycle 100% Operating speed at 400 Hz 2000 RPM Overload capacity (125% of rated load capacity) 325 A GENERATOR PROTECTIVE SYSTEM Overvoltage relay Undervoltage relay Overfrequency relay Underfrequency relay Overload relay Undervoltage time delay relay trips 130 V to 134 V; resets 125 V trips 102 V or below; resets 110 V trips 415 Hz to 425 Hz; resets 410 Hz trips 375 Hz to 385 Hz; resets 385 Hz trips 112 KVA in less than 5 minutes 4 to 12 seconds ENGINE Manufacturer John Deere Model 6059TL Type Turbocharged, In-line, 6-cylinder, 4-cycle Diesel Displacement 359 cu. in. (5.9 liters) Compression ratio 17.8:1 Firing order 1-5-3-6-2-4 Horsepower at 2000 RPM 123 Governed speed 2000 RPM +/- 4.5% Idle speed 850 +/- 25 RPM Electrical system 12 volt Oil capacity (with filter) 18 quarts (17 liters) Oil capacity (without filter) 16 quarts (15 liters) Coolant capacity (approx.) 20 quarts (19 liters) Fuel Diesel oil conforming to ASTM Specification D.975-66T, Nos. 1-D and 2-D Lube oil MIL-L-2104C or MIL-L-2104D Specifications and Capabilities Figure 2 1-1 November 30/91 Page 4
C.Hobart Engine Equipment The engine is modified at Hobart Brothers by the addition of the following equipment: (1) Electric governor system An electric governor kit is installed on the engine to replace a conventional, mechanical type. The electric governor was selected for control of engine speed (and generator output frequency) because it provides faster engine response to changes in load conditions. This fast response results in very close frequency control. Refer to the Barber Colman in Chapter 6 for a detailed description. A brief description is given below: The governor system consists of the following main components: (a) Magnetic pickup, (b) Control unit, and, (c) Actuator (a) Magnetic pickup This pickup is a device for detecting engine speed. It is mounted in the flywheel housing directly over the ring gear. It produces an AC signal to the control unit when the ferrous flywheel teeth pass through the magnetic field at the end of the pickup. (b) Control unit The control unit (13, Fig. 3) is a box containing a compact assembly of solid state components. It receives an AC signal from the magnetic pickup and senses speed changes in the engine. It provides a voltage signal to the actuator which causes the actuator to move the fuel control lever as required to maintain a predetermined engine speed. Its power is received from the 12-V DC battery system. (c) Actuator The actuator (16, Fig. 3) supplies the force needed to move and position the fuel lever as required to maintain a constant engine speed. The actuator is operated by a DC signal from the control unit. (2) Engine electrical system Items in the 12-volt engine electrical system that are provided by Hobart Brothers are: (a) A heavy-duty motor starter (b) Alternator with voltage regulator (c) Starting switch (d) Wiring harness (3) Engine protective devices (a) High coolant temperature switch A high coolant temperature switch is mounted in the front of the cylinder block to monitor the coolant temperature. If the coolant temperature reaches 210 degrees F (99 degrees C), this normally closed switch opens and de-energizes the fuel valve solenoid which shuts down the engine. (b) Oil pressure switch A diaphragm-type switch monitors the pressure in the lubricating oil system. It is mounted in the side of the cylinder block (9, Fig. 3). If the pressure in the lube oil system falls to 10 psi (69 kpa), this switch opens and de-energizes the fuel valve solenoid which shuts down the engine. November 30/91 1-1 Page 5
1. Generator 7. Quick-start kit 13. Governor control box 2. Battery 8. Air Cleaner 14. Engine control panel 3. Control box assembly 9. Engine assembly assembly 4. Muffler 10. Cooling fan 15. Exhaust pipe assembly 5. Rain cap 11. Radiator assembly 16. Governor actuator 6. 90 o elbow 12. Mounting frame 17. Load contactor Generator Set Components Figure 3 1-1 November 30/91 Page 6
(4) Air cleaner The diesel-engine air cleaner (Fig. 4) is so constructed that air enters it through the perforated cylindrical body of the air cleaner itself, and is filtered in the process before being passed on to the engine turbo-charge assembly. Air Cleaner Figure 4 (5) Exhaust system The exhaust system consists of a noise reducing muffler (2, Fig.5) which is connected by a pipe (1) to the exhaust manifold. The tail pipe (3) directs exhaust and noise upward. (6) Radiator (11, Fig. 3) This radiator is a one-piece item designed for long periods of operation without servicing. Refer to Section 2-1, Para. 7, G, for servicing procedure. November 30/91 1-1 Page 7
D. Generator 1. Pipe, manifold-to-muffler 2. Muffler 3. Tail Pipe Exhaust System Figure 5 The 400-Hz generator is a brushless, revolving field, three-phase, alternating current type. The rotor assembly is mounted by two, permanently lubricated, sealed, ball bearings. The front bearing is supported by the fan housing; the rear bearing is mounted in the exciter housing. Both of these housings are attached to the main generator stator housing. The front end of the rotor shaft extends forward beyond the rear bearing and into the exciter stator housing. The exciter rotor is mounted on this shaft extension with a Woodruff key and is secured by a washer and 1/2"-13 thd, cap screw. A rectifier with six diodes is mounted on the exciter rotor and converts exciter AC output to DC for excitation of the generator revolving fields. The exciter DC output to the generator fields, and consequently the generator output, is controlled by the amount of DC voltage supplied to exciter fields by the static voltage regulator. A centrifugal, radial-blade fan which is part of the hub and coupling assembly, draws cooling air over all internal windings. Air enters at the exciter end and is discharged at the drive end. The complete generator is bolted to the engine flywheel housing. 1-1 November 30/91 Page 8
E. Control Box Assembly The control box (Fig. 6) is a sheet metal enclosure which houses and provides mounting facilities for generator controls, and engine and generator monitoring equipment. For access to components mounted inside the control box, it is necessary to remove two 1/4 X 20-1/2-inch hex bolts, and to pull down the front panel, which is hinged to the control box at the bottom. (1) Front Panel (a) Generator output monitors (meters) The generator output is monitored by three instruments; a frequency meter (2), a voltmeter (3), and an ammeter (4) The frequency meter is a resonant-reed type, and indicates the frequency of the generator output alternating current in the range of 380 to 420 Hz (cycles per second). The voltmeter indicates the generator output voltage in each phase-to-neutral (A-N, B-N and C-N) or phase-to-phase (A-B, B-C and C-A) as selected by the meter selector switch (5) and the line selector switch (7). (These switches will be described below.) The voltmeter has a 3-1/2-inch face and the scale is graduated 0 to 300 V. The ammeter is also 3-1/2-inch sizeandisgraduated0to500a.theamperagevalueineachofthethreephasesmaybe read on the ammeter by selecting the desired phase with switch (5). Three ammeter current transformers, located beneath the generator control box support panel, lower the output load current to a lesser value, of definite ratio, which will operate the ammeter movement without damage. The ammeter dial scale is graduated and numbered so that the pointer will indicate the true load current value rather than the meter movement current. (b) Meter and line switches These switches provide a means of selecting and determining which phase of voltage and current is indicated on the voltmeter and ammeter and whether the voltage is line-to-neutral or line-to-line The meter switch (5) is a four-position, rotary type. A nameplate (6), located under the switch knob, is marked and lettered to indicate the three functional positions of the meter switch. (When the knob is pointing straight DOWN, the switch is OFF.) The line switch (7) is a two-position, toggle switch used to select either line-to-neutral or line-to-line voltage to the voltmeter. The nameplate is also marked to indicate position of this switch. (c) Instrument light A shielded, instrument panel light (1) is mounted at the left side of the control panel to illuminate controls, instruments, and indicator lights. It is controlled by a toggle switch on the engine control panel (3, Fig. 8) which also controls instrument light on the engine control control. (d) Indicating lights The function of these lights (10, 11, 12, 13 and 14) is to indicate, to the operator, the abnormal condition of overvoltage, underfrequency, etc., which caused the protective monitor system to function. Each of the five lights is connected to an actuating circuit within the memory and time delay module. When one of the circuits is activated, it turns on the applicable indicating light. The light will remain on until the reset switch (17) is pushed. All lamps in indicating lights may be tested by pressing switch (16). November 30/91 1-1 Page 9
1. Instrument panel light 11. Undervoltage indicating light 2. Frequency meter 12. Overfrequency indicating light 3. Voltmeter 13. Underfrequency indicating light 4. AC ammeter 14. Overload indicating light 5. Meter selector rotary switch 15. Hole plug 6. Instruction plate 16. Light test switch 7. Line selector toggle switch 17. Reset switch 8. Protective system fuse (2-A) 18. Regulated/diagnostic switch 9. Load contactor circuit fuse (2-A) 19. Aircraft/test-bank switch 10. Overvoltage indicating light Front Panel of Generator Control Box Figure 6 1-1 November 30/91 Page 10
(2) Control box internal components (Figure 7) Internally, the control box contains a solid-state voltage regulator, and electrical and safety devices designed to protect the aircraft electrical system against damage which could result from overvoltage, undervoltage, overfrequency, or underfrequency. Also contained therein are devices for the protection and control of the generator output electrical system. (a) Sensing modules The voltage sensing module (4) and frequency sensing module (6) are connected to generator output leads between the generator and load contactor. These solid-state modules sense any abnormal condition of voltage or frequency and signal the solid-state circuitry of the memory and time delay module (7) to open the load contactor and disconnect output to the aircraft. A solid-state overload signaling device (5) is also connected to the protective monitor module and performs a function similar to the voltage and frequency sensing modules. Trip values for protective circuits are as follows: Overvoltage trips at 130 V to 134 V Undervoltage trips at 102 V or below Overfrequency trips at 415 Hz to 425 Hz Underfrequency trips at 390 Hz to 395 Hz Undervoltage time delay (adjustable) Overload circuit trips at any value over 125% rated load capacity. Trip values are adjustable, however, adjustments should be made ONLY under laboratory conditions. SeePara6,H,(3) for more specific and detailed information regarding overload device. (b) Memory and time delay module The memory and time delay module (7) is sometimes called the protective monitor module. It is a solid-state device with a hermetically-sealed, reed-type relay. The printed circuit board or card includes five memory circuits and a time delay circuit. Each circuit is connected to a corresponding sensing circuit in the sensing modules (4, 5, and 6). All memory circuits are connected to the module relay coil, and any one of the circuits can energize the coil to open the relay contacts. Thus, when a sensing device energizes any one of the module circuits, the module relay is also energized to break the load contactor holding circuit and allow the load contactor to open. The module relay will remain energized (OPEN) and the light will remain ON until the reset switch (17, Fig. 6) is pushed to break the module 12-V DC cirucit, and allow the relay to return to normal, CLOSED position. All circuits, except the undervoltage circuit, function immediately to open the load contactor. A time delay system is designed into the undervoltage circuit to prevent nuisance opening of the contactor under conditions of momentary undervoltage in the generator output. An undervoltage condition which continues uninterrupted for a period of 4 to 12 seconds (adjustable) will cause the time delay circuit to open the load contactor. Each of the five circuits is connected to a corresponding indicating light (10, 11, 12, 13 and 14) whichisturnedonwhenafaultoccurs. (c) Excitation-deenergization relay The purpose of this relay (1) is to allow automatic excitation to be connected to the exciter field only when engine speed is being controlled by the electric governor. November 30/91 1-1 Page 11
(d) Plug-interlock relay The function of the plug interlock relay (2) is to cause the output load contactor to open in the event the cable plug connector becomes accidentally disconnected from the aircraft during power delivery, or if an attempt is made to deliver power when the output cable is not connected to the aircraft. Twenty-eight-volt, direct current for operation of the relay is supplied from the aircraft either through an on-board transformer-rectifier, or from a twenty-eight-volt, electrical system. Connection from the aircraft to the interlock relay is made through terminals E and F on the output cable plug connector. (e) Test-bank switch A spst, toggle switch (19) provides a means of bypassing the plug interlock relay (2) when supplying power to a load bank or to an aircraft not equipped with a plug interlock system. (f) Resistor A 100-ohm, 25-watt resistor (18) is connected in series with the plug interlock relay to protect the relay in the event that phase C contacts in the load contactor should fail to close when the generator ON switch is operated. (g) Fuse-interlock relay The function of the fuse-interlock relay (8) is to interrupt the load contactor holding coil circuit and remove the load in case of a blown fuse(8,fig.6)in the protective relay coil circuit. (h) Auxiliary underfrequency relay The function of the auxiliary underfrequency relay (9) is to automatically open the excitationdeenergization relay and disconnect the voltage regulator any time generator frequency drops to 380 Hz or below. This protects the voltage regulator PC board (13, Fig. 7) against overload which could be caused by high voltage regulator output in its attempt to maintain voltage when the generator is operating at a speed which cannot produce normal voltage output. NOTE: If the auxiliary underfrequency relay is tripped, it will be necessary to momentarily place engine operating mode switch (5, Fig. 8) in BUILD-UP-VOLTAGE position to restore generator voltage. (j ) Terminal boards Two terminal boards (14) provide connection facilities for small leads. (k) Solid-state voltage regulator This voltage regulator consists of two assemblies, a line-drop compensation assembly (17) and a voltage regulator PC board (13). A full and working description of this voltage regulator is provided in Solid State Regulator Manual OM-2020, which is a part of Chapter 6 of this manual. (l) Overload module (5) See Para. 6, H, (3) for functional description of the overload module. (m) Rectifier (10) See Para. 6, H, (4) for functional description of the load contactor rectifier. 1-1 November 30/91 Page 12
1. Excitation-deenergization relay 12. Bottom interior panel 2. Plug-interlock relay 13. Voltage regulator PC board 3. Rear interior panel 14. Terminal strips 4. Over-undervoltage module 15. Blocking diode assembly 5. Overload module 16. Ballast resistor, 6. Over-underfrequency module 20 ohm, 100 watt 7. Memory and time delay module 17. Line drop compensator 8. Fuse-interlock relay assembly 9. Auxiliary underfrequency relay 18. Resistor, 100 ohm, 25 watt 10. Contactor rectifier 19. Line drop burden resistors, 11. Overload burden resistors, 50 ohm, 25 watt 16.6 ohm, 25 watt Control Box Internal Components Figure 7 November 30/91 1-1 Page 13
F. Engine Control Panel (See Fig. 8) The engine control panel is mounted directly below the control box. Along with engine controls and instruments, generator output controls are mounted here. A plexiglas window in the canopy rear door, slants outward at the bottom to form an opening for access to controls when the door is closed. (1) Engine instruments Engine operation is monitored by an ammeter (4) a coolant temperature gage (8), and an oil pressure gage (10). An hourmeter (6) records engine operating time. (a) Ammeter The ammeter (4) indicates the direction and value of current flow in the 12-V DC electrical system. Its graduated range is from -60 A through 0 A, to +60 A. (b) Temperature gage The temperature gage (8) is a mechanical type of unit construction. It consists of a panel mounted indicating mechanism which is connected by a capillary tube to a bulb mounted in the engine cooling system. The gage indicates engine coolant temperature in the range of 100F to 220F. (c) Oil pressure gage and oil pressure switch The oil pressure gage (10) is a bourdon tube type and indicates engine lubricating oil pressure. It is graduated from 0 PSI to 75 PSI. An oil pressure switch is mounted in a tee fitting directly behind the gage. This switch connects 12-V DC power to the engine control system and to the generator 12-V DC control system when the engine is running. (d) Hourmeter The hourmeter (6) is electrically driven from the 12-V DC battery system. The hourmeter measures and records engine running time and will record up to 9999.9 hours on five revolving drums. The hourmeter operates only when the engine is running and the oil pressure switch is closed. (e) Fuel gage and blocking diodes An electric fuel gage (2, Fig. 8) accurately indicates the quantity of fuel oil in the tank provided for the generator set. A sending unit mounted in the trailer or truck mounted unit fuel tank supplies the signal to the gage. Twelve-volt DC operating power is supplied to the fuel gage from two sources. The gage functions when the engine is running, or when the instrument lights are ON. Since two power sources are connected to the fuel gage system, a blocking diode is required in each power source circuit. One diode prevents energizing the motor-generator control circuit when panel lights are ON. Another diode prevents operation of the panel lights by the engine-generator circuit when the engine is running. (See Connection Diagram in Chapter 6 for location of these diodes). To check fuel quantity when engine is stopped, use switch to turn on panel lights. 1-1 November 30/91 Page 14
(2) Engine and generator controls (a) Engine-generator control switch The engine-generator control switch (5) (also identified as the build-up-voltage, generate, idle switch) is a three-position toggle type. It is spring-loaded in one position, BUILD-UP- VOLTAGE, and will automatically reposition to GENERATE position when released. In BUILD-UP-VOLTS position it performs a dual function. First, it supplies power to the governor control box, which allows the engine to operate at normal governed speed; second, it momentarily supplies current for closing the excitation-deenergization relay (1, Fig. 7) contacts, to make three-phase, 115-V AC power available to the voltage regulator, or to the regulateddiagnostic circuit, for excitation of the generator exciter. In GENERATE position, power is maintained to the governor control box and to the excitation relay (1, Fig. 7). When the switch is placed in IDLE position, power is disconnected so that the engine returns to idle speed and the exciter field is deenergized. (b) Contactor control switch This is another three-position, toggle switch (7, Fig. 8) identical to the engine-generator control switch. When placed in the spring loaded CLOSE position, it provides 115-V AC power directly to a rectifier which supplies DC power for closing the load contactor. When released it returns to the normal ON position and continues to provide power to the rectifier, but in this switch position, AC power must pass through the plug interlock and fuse interlock relays. In OFF position the switch opens the AC circuit to the rectifier, thereby cutting off the source of DC power to the contactor coil which allows the contactor to open. (c) Instrument light and switch A shielded, instrument panel light (1) is mounted at the left side of the control panel. It is controlled by a toggle switch (3), which also controls instrument lights on the control box. (d) Engine starting circuit The pushbutton start switch (13) and permissive toggle switch (15) serve to connect power to the starter solenoid which functions to engage the starter gear with the flywheel ring gear and apply power to the starter motor to crank the engine. The permissive toggle switch (15) also stops the engine when the toggle is placed in the STOP (down) position. (e) Indicating lights A green indicating light (12) glows to indicate that power is available to the engine protective system. The light operates only when the engine permissive start switch (15) is in the START or RUN position. Another green indicating light (9, Fig. 8) glows when the generator output load contactor is CLOSED and power is available at the generator output cables. (f) Fuse A 10-ampere fuse (11) protects the 12-V DC engine control circuit, hourmeter, illuminating light circuit, and 12-V DC system in the main generator protective system. November 30/91 1-1 Page 15
1. Panel light 9.Load contactor indicating light 2. Fuel gage 10. Engine oil pressure gage 3. Light switch 11. Engine circuit fuse (10-A) 4. DC Ammeter 12. Engine ON indicating light 5. Engine-generator control switch 13. Engine starter switch 6. Hourmeter 14. Terminal strip (behind panel) 7. Load contactor control switch 15. Permissive start switch 8. Coolant temperature gage Engine Control Panel Figure 8 1-1 November 30/91 Page 16
G. Load Contactor Circuit Components Load contactor circuit components are located either attached beneath the control box support panel, on the trailer assembly, or inside the generator control box. The load contactor and its associated circuit components provide a means of connecting and disconnecting generator output to and from the load (aircraft). (1) Load contactor The load contactor (3, Fig. 9) is a sealed unit which contains a magnetic operating coil and four sets of contacts. The three larger contacts conduct three-phase AC generator output. A smaller contact set is connected in the protective monitor circuit and supplies 12-V DC power used by sensing relays to signal the protective monitor when a fault occurs. Three-phase, 400-Hz generator output power is conducted to the load contactor by 2/0 cables which pass through 3 sets of current transformers. (2) Current transformers Current transformers are located beneath the control box support panel directly below the control box. (a) Ammeter current transformers (2,Fig.10) Three current transformers lower the output load current to a lesser value of definite ratio (500-A to 5-A) which will operate the ammeter (4,Fig.6)movement without damage. The ammeter dial scale is graduated and numbered so that the ammeter pointer will indicate the true load current value rather than the meter movement current. (b) Line-drop current transformers (3, Fig. 10) The three line-drop current transformers in conjunction with burden resistors, detect the magnitude and power factor of current flowing from generator to load. They feed a signal to the voltage regulator which interprets the signal and alters the exciter field current as required to maintain a constant predetermined voltage at the load. (c) Overload current transformers (4, Fig. 10) Three overload current transformers, in conjunction with burden resistors monitor the output load current in each of the three output phases, and supply a reduced value current signal to theoverloadmodule(5, Fig 7) (3) Overload module The overload module is located inside the generator control box. This overload module (5, Fig 7) is a solid-state device designed to interpret a signal from the current transformers and to send a signal to the protective monitor module (7, Fig. 7) when an overload condition exists in any generator output phase. A pull-apart electrical connector is mounted on the overload module to provide quick-disconnect facilities for all wiring to the module. The overload module is equipped with a hermetically sealed, reed-type relay. Relay contacts are normally open. The solid-state circuitry is designed to close relay contacts when output current in ANY phase reaches 125% of normal rated output capacity. The closed relay sends a signal to the protective monitor. This signal gates the overload SCR (silicone-controlled rectifier) in the protective monitor and interrupts the load contactor holding circuit, allowing the load contactor to open. NOTE: The overload protective system will function when any phase carries 123% to 127% of rated load. At 125% load the module will function in 4 minutes. At 150% load the module will function in 16 seconds. At 200% load the module will function in 4 seconds. November 30/91 1-1 Page 17
NOTE: All times are plus or minus 25% and are nonadjustable. (4) Rectifier A diode bridge rectifier is located inside the generator control box. (See Fig. 7, item 10). This diode-bridge rectifier receives 400-Hz AC from phase C of the generator output an converts it to a pulsating, direct current for energization of the load contactor coil only. This DC coil-holding circuit is controlled indirectly be controlling the 400-Hz AC to the rectifier. The ground circuit for the rectifier s AC supply must pass through the relay contacts in the protective monitor module to ground cable N. Therefore, any time a protective device functions to open the protective monitor relay, the rectifier s AC circuit is opened. No DC is then available for the load contactor coil, hence, the load contactor opens. 1. Contactor panel 3. Load contactor 2. Neutral terminal 4. E-F terminal Load Contactor Panel Figure 9 1-1 November 30/91 Page 18
1.Bottom of control box 2.Ammeter current transformers 3.Line drop current transformers 4.Overload current transformers Current Transformers Figure 10 November 30/91 1-1 Page 19
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Section 2. Preparation For Use, Storage, Or Shipping 1. Preparation for Use A. Inspection/Check Inspect the unit thoroughly prior to operation. (1) Remove blocking, banding, ties, and other securing material. (2) Inspect exterior for shipping damage such broken lights, damaged sheet metal, etc. (3) Open all canopy doors and inspect interior for foreign material such as rags, tools, shipping papers, etc. (4) Check fuel, coolant, and oil hoses and connections for visible leaks. Visually inspect the compartment floor and ground surface under the unit for signs of leakage. If leaks are found, correct by tightening hose clamps, tube fittings, etc., as required. (5) Check the following for sufficient quantity: (a) Fuel Place engine permissive start switch (1-1; 15, Fig. 8) in the RUN position to energize fuel gage when engine is stopped. (b) Engine coolant The radiator cap is accessible by opening the hinged access cover on the front canopy housing. Coolant level should be approximately one inch below the filler neck. Allow a capacity for coolant expansion. CAUTION: BE SURE THE COOLING SYSTEM ANTIFREEZE SOLUTION IS ADEQUATE TO PRO- TECT BELOW LOWEST TEMPERATURE EXPECTED. NOTE: For antifreeze protection, use a solution of 50% permanent antifreeze (Ethylene glycol) and 50% clean water. (c) Engine lubricating oil Oil level should be at FULL mark on oil level gage rod. See the John Deere Shop Manual for oil recommendations. (6) Check air cleaner The air cleaner (Sect. 1-1, Fig. 3, item 8) is a dry type. Be sure there are no papers, tapes, or other material covering the air inlet area. B. Installing Three-phase AC Output Cables Units are generally shipped without generator set-to-aircraft cables. The load contactor, at which cables must be connected is located on the left side of the unit beside the engine control panel (see 1-1; 2, Fig. 3). To install AC output cables proceed as follows. (1) Open and raise left rear canopy door of the generator set. (2) Loosen screws on cable clamp located on the cable tray on the left side of the generator set. (3) Remove lexan cover over the load contactor. (4) Route cables through cable clamp, and up to the load side (bottom) of the load contactor. November 30/91 1-2 Page 1
NOTE: Conductor size recommended for AC output is 2/0 size. Use No. 12 size for control (E and F terminals). Large cables (A, B, C, N) should be equipped with terminals having at least a 3/8-inch diameter mounting hole. Mounting hole in small leads (E and F) should be at least 1/4-inch diameter. (5) Remove the terminal cover on the load side of the contactor and connect the phase cable terminal lugs to the appropriate terminal studs on the contactor: cable lug A to terminal stud A, B to B, and C to C. (6) Connect the cable s neutral terminal lug securely to the neutral (ground) stud on the side of the load contactor mounting bracket. (7) Tighten terminal nuts securely and replace the terminal cover on the load contactor. Connect small plug interlock leads E and F to terminal E-F on the side of the load contactor mounting bracket. (8) Tighten clamp screws securely on the left side of the unit, but avoid damage to cable insulation. (9) Replace lexan cover over load contactor. 2. Preparation for Storage When a generator set is to be stored or removed from operation, special precautions should be taken to protect the internal and external parts from rust, corrosion, and gumming in the engine fuel system. A. General (1) The unit should be prepared for storage as soon as possible after being removed from service. (2) The unit should be stored in a building which is dry and which may be heated during winter months. (3) Moisture absorbing chemicals are available for use where excessive dampness is a problem, however the unit must be completely packaged and sealed if moisture absorbing chemicals are to be effective. B. Temporary Storage When storing the unit for 30 days or less, prepare as follows: (1) Lubricate the unit completely in accordance with instructions in Sect. 2-1. This will include changing engine oil, and all filter elements. (2) Start the engine and operate for about two minutes so that all internal engine components will be coated with new oil. NOTE: Do not drain the fuel system or crankcase after this run. (3) Make certain the cooling system antifreeze solution is adequate to protect below the lowest temperatures expected during the storage period. See 2-1; Para. 7, D. Be sure the solution is thoroughly mixed. (4) Clean the exterior of the engine with fuel oil. Dry with clean rags and compressed air. (5) Seal all engine openings. Use a waterproof, vaporproof material which is strong enough to resist puncture damage from air pressures. 1-2 November 30/91 Page 2
C. Long Time Storage (Over 30 Days) (1) The unit may be stored for long periods with no special preparation if it is possible to operate the engineonceeachweek. (a) Make certain the cooling system is adequately protected WARNING: MAKE CERTAIN OF ADEQUATE VENTILATION BEFORE STARTING THE ENGINE. (b) Start the engine and operate at a fast idle (800 to 1000 RPM) until coolant temperature has reached at least 140 deg F. (c) Operate normal operating controls. (2) If weekly operation is not possible, prepare and protect the engine in accordance with instructions in the John Deere Operator s Manual. (3) To protect the generator and other electrical components, the complete unit should be packaged, using moisture proof packaging and sealing material. Place containers of moisture absorbing chemicals, such as silica-gel, in the unit before packaging. November 30/91 1-2 Page 3
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Section 3. Operation 1. General This section contains information and instructions for the safe and efficient operation of the equipment. Operating instructions are presented in step-by-step sequence of procedures to be followed in supplying 400-Hz power to an aircraft. WARNING: IMPROPER OPERATION CAN KILL! EAR PROTECTION EQUIPMENT MAY BE NEC- ESSARY WHEN WORKING IN CLOSE PROXIMITY TO THIS EQUIPMENT. READ AND FOLLOW ALL OF THE OPERATING INSTRUCTIONS BEFORE ATTEMPTING TO OPERATE THE EQUIP- MENT. 2. Operating the Generator Set A. Pre-start Inspection (1) Open the fuel shut-off valve. (2) Provide 12-V DC power to the engine starting system. (3) Check the engine and generator compartments and remove rags or other foreign materials. B. Normal Engine Starting Procedures Engine starting procedures are outlined below. Engine operating controls and monitoring instruments are illustrated in Fig. 1. (1) If illumination is required, place light switch (13) in ON position. NOTE: This switch must be ON to check fuel when engine is stopped. (2) Hold engine start switch (24, Fig. 1) in START position momentarily. Push engine start pushbutton (23) to crank engine. When engine starts, release pushbutton. Continue to hold engine start switch (24) in position until oil pressure gage (20) reads at least 20 PSI pressure. Release switch (24). (3) Check ammeter (3) for charge reading. (4) Check fuel gage (12) and oil gage (20). (5) Place engine generator control switch (15) in IDLE position. (6) Activate generator output contactor switch (17). November 30/91 1-3 Page 1