OPERATION AND MAINTENANCE MANUAL

Transcription

1 OPERATION AND MAINTENANCE MANUAL with ILLUSTRATED PARTS LIST for ENGINE-DRIVEN GENERATOR SET Part Number MODEL90GT20 90-KVA, 400-HZ, 115/200-V AC, 3-PHASE TRAILER-MOUNTED Hobart Brothers Company Airport Systems Group Ground Power Equipment Troy, Ohio U.S.A.

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3 Safety Warnings and Cautions WARNING CALIFORNIA PROPOSITION 65 - GASOLINE ENGINES. The engine exhaust from this product contains chemicals known to the State of California to cause cancer, birth defects or other reproductive harm. WARNING CALIFORNIA PROPOSITION 65 - DIESEL ENGINES. Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects and other reproductive harm. WARNING ELECTRIC SHOCK can KILL. Do not touch live electrical parts. ELECTRIC ARC FLASH can injure eyes, burn skin, cause equipment damage, and ignite combustible material. DO NOT use power cables to break load and prevent tools from causing short circuits. IMPROPER PHASE CONNECTION, PARALLELING, OR USE can damage this and attached equipment. IMPORTANT Protect all operating personnel. Read, understand, and follow all instructions in the Operating/Instruction Manual before installing, operating, or servicing the equipment. Keep the manual available for future use by all operators. 1. General Equipment that supplies electrical power can cause serious injury or death, or damage to other equipment or property. The operator must strictly observe all safety rules and take precautionary actions. Safe practices have been developed from past experience in the use of power source equipment. While certain practices below apply only to electrically-powered equipment, other practices apply to engine-driven equipment, and some practices to both. Revised Safety Warnings August 01/95 Page 1

4 2. Shock Prevention Bare conductors, or terminals in the output circuit, or ungrounded, electrically-live equipment can fatally shock a person. Have a certified electrician verify that the equipment is adequately grounded and learn what terminals and parts are electrically HOT. Avoid hot spots on machine. Use proper safety clothing, procedures, and test equipment. The electrical resistance of the body is decreased when wet, permitting dangerous currents to flow through it. When inspecting or servicing equipment, do not work in damp areas. Stand on a dry rubber mat or dry wood, use insulating gloves when dampness or sweat cannot be avoided. Keep clothing dry, and never work alone a. Installation and Grounding of Electrically Powered Equipment Equipment driven by electric motors (rather than by diesel or gasoline engines) must be installed and maintained in accordance with the National Electrical Code, ANSI/NFPA 70, or other applicable codes. A power disconnect switch or circuit breaker must be located at the equipment. Check the nameplate for voltage, frequency, and phase requirements. If only 3-phase power is available, connect any single-phase rated equipment to only two wires of the 3-phase line. DO NOT CONNECT the equipment grounding conductor (lead) to the third live wire of the 3-phase line, as this makes the equipment frame electrically HOT, which can cause a fatal shock. Always connect the grounding lead, if supplied in a power line cable, to the grounded switch box or building ground. If not provided, use a separate grounding lead. Ensure that the current (amperage) capacity of the grounding lead will be adequate for the worst fault current situation. Refer to the National Electrical Code ANSI/NFPA 70 for details. Do not remove plug ground prongs. Use correctly mating receptacles. b. Output Cables and Terminals Inspect cables frequently for damage to the insulation and the connectors. Replace or repair cracked or worn cables immediately. Do not overload cables. Do not touch output terminal while equipment is energized. 3. Service and Maintenance This equipment must be maintained in good electrical and mechanical condition to avoid hazards stemming from disrepair. Report any equipment defect or safety hazard to the supervisor and discontinue use of the equipment until its safety has been assured. Repairs should be made by qualified personnel only. Before inspecting or servicing electrically-powered equipment, take the following precautions: a. Shut OFF all power at the disconnecting switch or line breaker before inspecting or servicing the equipment. b. Lock switch OPEN (or remove line fuses) so that power cannot be turned on accidentally. c. Disconnect power to equipment if it is out of service. d. If troubleshooting must be done with the unit energized, have another person present who is trained in turning off the equipment and providing or calling for first aid. 4. Fire And Explosion Prevention Fire and explosion are caused by electrical short circuits, combustible material near engine exhaust piping, misuse of batteries and fuel, or unsafe operating or fueling conditions. a. Electrical Short Circuits and Overloads Overloaded or shorted equipment can become hot enough to cause fires by self destruction or by causing nearby combustibles to ignite. For electrically-powered equipment, provide primary input protection to remove short circuited or heavily overloaded equipment from the line. Safety Warnings Revised Page 2 August 01/95

5 b. Batteries Batteries may explode and/or give off flammable hydrogen gas. Acid and arcing from a ruptured battery can cause fires and additional failures. When servicing, do not smoke, cause sparking, or use open flame near the battery. c. Engine Fuel Use only approved fuel container or fueling system. Fires and explosions can occur if the fuel tank is not grounded prior to or during fuel transfer. Shut unit DOWN before removing fuel tank cap. DO NOT completely fill tank, because heat from the equipment may cause fuel expansion overflow. Remove all spilled fuel IMMEDIATELY, including any that penetrates the unit. After clean-up, open equipment doors and blow fumes away with compressed air. 5. Toxic Fume Prevention Carbon monoxide - Engine exhaust fumes can kill and cause health problems. Pipe or vent the exhaust fumes to a suitable exhaust duct or outdoors. Never locate engine exhausts near intake ducts of air conditioners. 6. Bodily Injury Prevention Serious injury can result from contact with fans inside some equipment. Shut DOWN such equipment for inspection and routine maintenance. When equipment is in operation, use extreme care in doing necessary trouble-shooting and adjustment. Do not remove guards while equipment is operating. 7. Medical and First Aid Treatment First aid facilities and a qualified first aid person should be available for each shift for immediate treatment of all injury victims. Electric shock victims should be checked by a physician and taken to a hospital immediately if any abnormal signs are observed. EMERGENCY FIRST AID Call physician immediately. Seek additional assistance. Use First Aid techniques recommended by American Red Cross until medical help arrives. IF BREATHING IS DIFFICULT, give oxygen, if available, and have victim lie down. FOR ELECTRICAL SHOCK, turn off power. Remove victim; if not breathing, begin artificial respiration, preferably mouth-to-mouth. If no detectable pulse, begin external heart massage. CALL EMERGENCY RESCUE SQUAD IMMEDIATELY. 8. Equipment Precautionary Labels Inspect all precautionary labels on the equipment monthly. Order and inspect all labels that cannot be easily read. Revised Safety Warnings August 01/95 Page 3

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7 INTRODUCTION This manual contains operation and maintenance information for a 400-Hertz generator set manufactured by Hobart Brothers Company, Airport Systems Group, Troy, Ohio 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 Nov 30/93 Introduction Page 1

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9 Table of Contents OM-2072 SUBJECT CHAPTEFUSECTION PAGE WARNING LIST OF EFFECTIVE PAGES INTRODUCTION CHAPTER 1. DESCRIPTION/OPERATION SECTION 1. DESCRIPTION 1. General 2. Orientation 3. Special Features A. Protective Monitor B. Pug-out Trays C. Voltage Regulator D. Test Circuitry E. Electric Governor F. Low Fuel Level Shutdown Switch G. Cold Weather Starting Aid H. Water Heater Kit 4. Optional Equipment A. Trailer B. Transformer-Rectifier C.Second Output and Control Box D. Memory and Time Delay Board 5. Canopy 6. Engine, Generator, and Controls Assembly A. Basic Engine B. Engine Manufacturer s Equipment C. Hobart Engine Equipment (1) Electric governor system (a) Magnetic pickup (b) Control unit (c) Actuator (2) Engine electrical system (3) Engine protective devices (4) Air cleaner (5) Exhaust system (6) Radiator D. Generator l-1 l-l l-l l-l l-l 1-l 1-l 1-l 1-l 1-l l-l 1-l l-l l-l 1-l 1-l I-l l-l l-l l-l 1-l 1-l l-l 1-l l-1 1-l 1-l 11 1-l 1-l l-l 1-l 1 : Nov 3Ol63 Table of Contents Page 1

10 SUBJECT CHAPTER/SECTION PAGE E. Control Box Assembly (1) Generator control tray (a) Resistors (b) Generator output monitors (meters) (c) Meter and line switches (d) Receptacle connector 63 Tray (9 Manual voltage control (g) Excitationdeenergization relay (2) Protective relay tray (a) Sensing modules (b) Memory and time delay module (c) Indicating lights (d) Plug-interlock relay (e) Test-bank switch (9 Resistor (g) Fuse-interlock relay (h) Connector (k) Auxiliary underfrequency relay F. Engine Control Panel (1) Engine Instruments (2) Engine and generator controls (3) Air cleaner indicator (4) Test receptacle connector G. Power Module Panel Assembly (1) Load contactor (2) Currant transformers (3) Overload module (4) Rectifier (6) Terminal boards 6. Test Box A. Description B. Theory of Operation SECTION 2. PREPARATION STORAGE, OR SHIPPING FOR USE, 1. Preparation for Use A. General B. Inspection/Check C. Installing Output Cables (1) Three-phase, AC output cable assembly installation (2) Transformer-Rectifier (DC) output cable installation I-l I-l i-1 1-l 1-l 1-I 1-l 1-l 1-l i-1 i-1 l-l 1-l 1-l 1-l I-1 1-l 1-l 1-l 1-l 1-l 1-l 1-l 1-l 1-l 1-l 1-l 1-l l-1 1-l ::: 1-l I l-2 l-2 l l IO :i Table of Contents Page 2 Nov 30/93

11 SUBJECT CHAPTER/SECTION PAGE 2. Preparation for Storage A. General B. Temporary Storage C. Long Time Storage (Over 36 Days) 1-2 l-2 l-2 l SECTION 3. OPERATION 1.General 2. Operating the Generator Set A. Pm-start Inspection 8. Normal Engine Starting Procedures C. Cold Weather Engine Starting Procedures D. Preparation for Power Delivery (Automatic Voltage Control) E. Power Delivery (Automatic Voltage Control) F. Preparation for Power Delivery (Manual Voltage Control) G. Power Delivery (Manual Voltage Control) H. Discontinue Power Delivery K. Stopping the Engine 3. Test Box Operation 4. Transformer-Rectifier Operation A. Direct Current Power Delivery B. Simultaneous 26.6-V DC and 116-V AC Power Dalivery 5. Tr i~;w~n~tion (Optional) B. Parking CHAPTER l l-3 13 l-3 l-3 l-3 l-3 l-3 l-3 l-3 ::; l-3 13 l l SERVICE SECTION 1. MAINTENANCE General Inspection Lubrication 2-l A. General 2-1 B. Generator 2-1 C. Generator Controls 2-l D. Engine 2-1 (1) Lubrication schedule 2-l (2) Oil specification 2-l (3) Oil viscosity 2-l (4) Changing engine oil 2-l (6) Changing engine oil filter 2-l E. Starter Nov 30/93 Table of Contents Page 3

12 DM-2072 SUBJECT CHAPTEWSECTION PAGE 4. Air Cleaner Service A. Inspecting the Air Cleaner B. Cleaning Instructions (1) Pressurized Air Cleaning (2) Low Pressure water Flush (3) Disposal C. Disposal 5. E;ginfa;d B: Fuel Filter 6. E;gin~n~~oling System B. Radiator Cap (1) General (2) Removal (3) Installation C. Warm Weather Operation D. Cold Weather Operation (1) General (2) Checking coolant solution (3) Preparing the coolant solution (4) Installing the antifreeze solution E. Draining the Cooling System F. Cleaning the Cooling System G. Cleaning the Radiator Core H. Filling the Cooling System 7. Generator Maintenance A. Cleaning B. Adjustment 6. Drive Belts A. Checking Belt Tension B. Belt Adjustment 9. Trailer and Battery Maintenance 10. Service Helps A. Wiring B.Control Box Trays C. Generator Exciter D. Engine Control Panel SECTION 2. INSPECTION/CHECK 1. General 2. Engine A. Fuel B. Lubrication C. Coolant D. V-Belts l l i Table of Contents Page 4 Nov 30/63

13 SUBJECT CHAPTEWSECTION PAGE E. Exhaust System 3. Electrical System (12-V DC) A. Lights B. Fuses C. Wiring and Connections 4. Electrical System (115-V AC) A. Monitoring Instruments B. Indicating Lights C. Protective Modules D. Wiring and Connections 5. Servicing and Troubleshooting the Cold Weather Starting Aid A. Check Fluid Cylinder Contents and Valve Gasket B. Checkof Electrical System C. Check for Clogging of Flow Metering Orfice Fitting 6. Trailer SECTION 3. ADJUSTMENT/TEST 1. General 2. Generator Set Test A. Pm-operational Test Procedures B. Operational Test Procedures 3. Generator Set Adjustment A. Generator Adjustment B. Generator Control Adjustments C. Basic Engine Adjustments D. Engine Accessories Adjustment E. Electric Governor System Adjustment (1) Actuator linkage adjustment (2) Magnetic pickup adjustment (3) Adjustment and Test of Controller and Actuator (a) Preliminary Controller Settings (b) Checking No-Load Operation of Controller (c) Adjusting for Rated Speed Operation (d) Checking the Actuator (e) Checking Operation of Controller Under Load (9 Checking Magnetic Pick-up signal 5. Generator and Exciter Test 6. Diode Test A. Disconnect diode lead(s) Nov 30/93 Table of Contents Page 5

14 CHAPTER 3. TROUBLESHOOTING SUBJECT CHAPTER/SECTION PAGE SECTION 1. TROUBLE SHOOTING PROCEDURES General Trouble Shooting Chart (Figure 5) 3-1 : ;. E.z;u;ment for Troubleshooting l 2 5: Parts Replacement 6. Test Values g:; i 7. Checking Connections and Leads 6. Electric Governor Trouble Shooting g: : 9. Engine Trouble Shooting Procedures A. General lo.lllustrations CHAPTER 4. ILLUSTRATED QUARTS LIST SECTION 1. INTRODUCTION General Purpose : 3. Arrangement ;:: 1 4. Explanation of Parts List A. Contents B. Parts List Form SECTION 2. MANUFACTURER S CODES 4~ Explanation of Manufacturer s (Vendor) Code List SECTION 3. PARTS LIST Explanation of Parts List Arrangement Symbols and Abbreviations CHAPTER 5. OPTIONAL EYUIPMENT CHAPTER 6. MANUFACTURERS LITERATURE UNUSUAL SERVICE CONDITIONS Table of Contents Page 6 Nov 3Om3

15 CHAPTER 1. DESCRIPTION/OPERATION SECTION 1. DESCRIPTION 1. General The generator set covered by this manual is identified by part number It features an armature with Hover Bearings, Browning Coupler, and a new type of 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. In addition, this generator set also features widetype Fafnir bearings on the generator. This unit is mounted on a 5th-Wheel Trailer, and is equipped with a solid-state voltage regulator, Hobart Part No The engine in this generator set 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. The engine, generator, and controls are designed into a compact unit. See Figure 2 for specifications and capabilities. 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. Thus, the generator control box, output receptacle connector, and engine control panel are mounted on the LEFT side at the REAR of the unit. 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 (4, Fig. 8) 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. B. Pull-out Trays The control box is equipped with pull-out, drawer-type trays (Fig. 6) which provide easy access to controls and equipment mounted in them. Each tray may be removed as an assembly by disconnecting a single quick-disconnect connector and tripping two safety latches. Nov 30/ Page 1

16 1. Canopy 6. Output cable horn 2. Access-vent covers 7. Mounting frame 3. Lifting eye 8. Engine fan exhaust deflectors 4. Windows 9. Engine exhaust pipe 5. Output receptacle cover 10. Radiator cap access cover Generator Set Figure Nov 30/93 Page 2

17 C. Voltage Regulator The solid state electronic voltage regulator (Hobart Part No ) provides automatic voltage regulation at the aircraft. The regulator is adjustable for a variety of output cable sizes and lengths. D. Test Circuitry A receptacle connector (19, Fig. 9) with wiring to various test points throughout the electrical circuitry is provided for the attachment of a test box manufactured by Hobart Brothers. This test circuitry allows electricians to perform as many as twenty-four tests and checks from one location, conveniently and easily. E. Electric Governor The engine is equipped with an all electric type governor kit (5 and 12, Fig. 3) and other special equipment more fully described under the engine description. F. Low Fuel Level Shutdown Switch On this unit, the fuel tank is equipped with a low fuel level shutdown switch. This switch is placed at such a point in the tank that, when the fuel level is low, the switch opens a relay (located on the back of the generator control box) which opens the fuel valve solenoid on the engine, cutting off fuel to the engine. This low fuel shutdown circuit is shown on Schematic Diagram , in the lower right corner of the diagram, in Chapter 6. Circuit components are identified on the diagram as follows: S54 K65 L7 CR30 Low fuel level switch Low fuel level relay Fuel valve solenoid Low fuel level flyback diode G. Cold Weather Starting Aid A starting aid is installed on this generator set to assist in starting the engine at low temperatures. The starting aid, identified by Hobart Part Number , operates automatically during cranking to spray a controlled amount of starting fluid into the engine s air intake system. This is accomplished by use of a relay wired to the starter solenoid, which controls starting fluid flow from the starting aid cylinder. This starting aid is thermostatically controlled, and only operates at temperatures below 40 o F. For operating instructions, see Sect. 1-3, Para. H. Water Heater Kit CAUTION: DO NOT OPERATE THIS HEATER WHILE THE ENGINE IS RUNNING, AND DO NOT RUN ENGINE WHILE THIS HEATER IS OPERATING. CAUTION: DRAIN THE ENGINE COOLANT SYSTEM BEFORE WORKING ON THE HEATER. AFTERWARDS, REFILL THE COOLING SYSTEM AND BLEED AT HIGHEST POINT TO REMOVE ANY AIR LOCK. This generator set is equipped with a water heater kit to heat the engine block and thus keep the coolant warm when the engine is shut down for extended periods of time in cold weather. This permits the engine to start more quickly. The water heater kit is installed inside the enclosure of the generator set, and is connected to the cooling system of the diesel engine which drives the unit. This water heater kit is illustrated as Figure 19 in Section 4-3. As illustrated in Figure 19, the heater unit is mounted to the generator frame with a bracket and attaching hardware. Hoses, clamps, and fit- Nov 30/ Page 3

18 tings connect the heater to the engine s cooling system: heater input to the engine water inlet from the radiator; heater output to the engine thermostat housing. The heater element is connected to 115 VAC, 50 or 60 cycle line current by plugging an extension cord into the weatherproof inlet (Item 13, Figure 19) that is mounted into the generator frame. A thermostat turns the heater element ON at 140 o F (60 o C) and OFF at 160 o F (71 o C). Heated coolant is circulated throughout the cooling system by a thermal siphoning action. Mounted low in the system, a head pressure is maintained at the heater s intake and a simple oneway valve in the heater unit insures the direction of coolant flow. BASIC UNIT PHYSICAL Length overall Width Height overall Weight 88 inches (2235 mm) 36 inches (914.4 mm) 43 inches ( mm) 3500 pounds ( kg) FIFTH-WHEEL TRAILER-MOUNTED UNIT Length overall Width Height Weight 131 inches (3327 mm) 78 inches (1981 mm) 70 inches (1778 mm) 4840 pounds (2195 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 Overvoltage relay ** Undervoltage relay Overfrequency relay ** Underfrequency relay * Overload relay Undervoltage time delay relay PROTECTIVE SYSTEM 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 * This relay is available with an optional time delay. For details refer to Paragraph 7, E, (2), (a). ** For these relays an optional memory and time delay PC module is available. For details refer to Paragraph7,E,(2),(a). Specifications and Capabilities Figure 2 (Sheet 1 of 2) 1-1 Nov 30/93 Page 4

19 Manufacturer/Model Type ENGINE John Deere, Model 6059TL Turbocharged, In-line, 6-cylinder, 4-cycle Diesel 359 cu. in. (5.9 liters) Displacement Compression ratio 16.8:1 Firing order Number of main bearings 7 Horsepower at 2000 RPM 123 Governed speed 2000 RPM +/- 4.5% Idle speed Electrical system Oil capacity (with filter) Oil capacity (without filter) Coolant capacity (approx.) Fuel 850 RPM +/- 25 RPM 12 volt 18 quarts (14 liters) 146 quarts (13.6 liters) 20 quarts (19 liters) Diesel oil conforming to ASTM Spec. D T, Nos. 1-D and 2-D (Diesel oil No. 1, No. 2, or Jet A-1) Specifications and Capabilities Figure 2 (Sheet 2 of 2 4. Optional Equipment Several items of optional equipment are available for units covered by this manual. Each optional item is covered by its own Instruction and Parts Manual and will not be covered in this basic manual. When applicable, information for optional equipment will be located in Chapter 5. Options are listed as follows: A. Trailers A fifth-wheel trailer with batteries and fuel tank is available. B. Transformer-Rectifier A transformer-rectifier (T-R) is available for use with the generator set. This T-R receives 115/200-V, 400-Hz, AC power from the generator and converts it to a 28.5 V DC output. C. Second Output and Control Box An auxiliary output and control box is available to provide a second independent 115-V AC output circuit. Nov 30/ Page 5

20 F. Memory and Time Delay PC Board (Part No ) 5. Canopy In a Hobart generator set, the memory and time delay module is an integral part of the circuitry that protects the aircraft electrical system against damage which could result from overvoltage, undervoltage, overfrequency, or underfrequency. A voltage sensing module and a frequency sensing module 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 to open the load contactor and disconnect output to the aircraft. For overvoltage, overfrequency and underfrequency conditions, the memory and time delay module functions instantly to open the load contactor and disconnect output to the aircraft. But a unit equipped with the special memory/time-delay module (depending on the DASH NUMBER selected) permits various lengths of time delay for opening the load contactor at the occurrence of abnormal conditions of voltage or frequency. When selected, this option is explained in detail in TO- 210, which would be found in Chapter 5 of this manual. This generator set is equipped with a sheet metal enclosure, identified as a canopy (1, Fig. 1), which provides protection for the engine, generator and electrical controls. This canopy has doors on both sides. Panel mounted instruments may be observed through two Plexiglass 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. A centrally-located lifting eye attached to a lifting yoke extends through the canopy top to provide an attaching point for chains, cables, or hook used to lift and move the generator set. The canopy is designed to reduce the operational noise level in the immediate area of the machine. Doors and panels are covered on the inside with Fiberglass acoustic material to reduce reflected and conducted noise, and to absorb noise. Noise producing vibration in most frequently used doors on the left side is reduced by the use of two-point slam locks. Less frequently used doors on the right side are equipped with screw-operated latch fasteners which are tightened after latching to reduce vibration. Insulating strips around all doors also reduce noise. Metal strips are mounted horizontally across the front grille to deflect engine fan exhaust air and noise upward. Two large openings in the canopy top provide an entrance for cooling air and access to internal components. A hood-type cover is mounted about two inches above each opening. The cover is flanged downward and extends beyond the edges of the upwardly flanged opening to prevent entrance of blowing rain while still allowing good air flow. Air enters the forward opening into the engine compartment and is discharged through the radiator by the engine fan. Air enters the rear opening into the generator compartment. It is then circulated over generator controls and drawn into the rear exciter and generator housings, passing over all windings before being discharged by the generator fan. 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, three-phase 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, electrical equipment and controls. A. Basic Engine This generator set is equipped with a 6-cylinder, in-line, turbo-charged John Deere Diesel engine. See Figure 2 for general Parts, and see Engine Operator s Handbook in Chapter 6 for more detailed information. 1-1 Nov 30/93 Page 6

21 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 (Chapter 6). (1) Fuel filter. (2) Reverse-flow, engine cooling fan to blow air outward through the radiator. 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 rather than 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 Coleman Handbook in Chapter 6 for a detailed description. As briefly described below, the governor system consists of three main components: the magnetic pickup, the control unit, and the actuator. (a) Magnetic pickup The magnetic pickup is a device for detecting the speed of the engine. 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 (5,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 (12, 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 back of the cylinder block to monitor the coolant temperature. If the coolant temperature reaches 210 o F (99 o C), this normally closed switch opens and actuates the fuel valve solenoid which shuts down the engine. Nov 30/ Page 7

22 1. Mounting frame 8. Air cleaner 14. Engine control panel 2. Generator 9. Lifting yoke 15. Cable horn and clamp 3. Power module 10. Engine 16. Radiator 4. Control box 11. Engine exhaust pipe 17. Fuel valve solenoid 5. Governor control box 12. Governor actuator 18. Oil pressure switch 6.* Starting fluid container 13. Output cable terminal 19. Muffler 7. Voltage regulator board Generator Set Components Figure Nov 30/93 Page 8

23 (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 (18, Fig. 3). If the pressure in the lube oil system falls to 10 psi (69 kpa), this switch opens and actuates the fuel valve solenoid which shuts down the engine. (4) Air cleaner The diesel-engine air cleaner (Fig. 4) is a dry-cartridge type. It is equipped with a moisture eliminator and a service indicator. The indicator functions to signal the operator when the cartridge needs changing. A red cylindrical flag is forced upward in a glass enclosed viewing chamber when air pressure within the air cleaner housing drops below the outside air pressure. As the cartridge becomes loaded with dirt and air pressure within the cleaner lessens, the flag gradually rises higher in the glass viewing chamber. When the flag reaches the top of the chamber, it locks in that position to warn the operator that the cartridge must be changed. The flag is reset (unlocked) by pushing the reset button located on the bottom of the indicator. NOTE: The service indicator is mounted on the engine control panel and connected to the air cleaner by a rubber hose. The indicator flag is visible only when the engine is running, or when the flag is locked in WARNING position. (5) Exhaust system The exhaust system (Fig 5) consists of a special noise reducing muffler connected by a pipe to the exhaust manifold. The tail pipe directs exhaust and noise upward. (6) Radiator D. Generator The radiator (16, Fig. 3) is a one-piece item designed for long periods of operation without servicing. Refer to Section 2-1, Para. 7, G, for servicing procedure. 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 supported by the fan housing; the rear bearing 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 - 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. Nov 30/ Page 9

24 Air Cleaner and Service Indicator Figure 4 E. Control Box Assembly The control box (Fig. 6) is a sheet metal enclosure which houses and provides mounting facilities for generator and engine controls and monitoring equipment. The box is equipped with two, drawer type trays which contain generator output control devices and monitoring instruments. Trays slide in and out on nylon rollers for easy access to internally mounted components. Each tray is easily removable by disconnecting an Amphenol connector, unlocking safety latches, and sliding the complete tray assembly out of the control box. A shielded, instrument panel light is mounted on the left side of the control box front panel, to illuminate controls and instruments in the trays. (1) Generator control tray (See Figure 7) The generator control tray contains instruments and controls for monitoring and controlling the generator output. (a) Resistors Two, 10-ohm, 100-watt, ballast resistors (2) are connected in series in the generator exciter DC field circuit. A variable resistor (1) is connected in series between the manual control rectifier (14) and rheostat (13). Its purpose is to adjust the DC voltage to the rheostat and thus determine the voltage range through which the rheostat can control generator output voltage. 1-1 Nov 30/93 Page 10

25 (b) Generator output monitors (meters) The generator output is monitored by three instruments; a frequency meter (10), a voltmeter (9), and an ammeter (7). 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 (6) and the line selector switch (5). (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 (6). Three ammeter current transformers (Ref. 4, Fig. 11) 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. (c) Meter and line switches Exhaust System Figure 5 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 (6) is a four-position, rotary type. A nameplate (4), 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 (5) is a two position, toggle switch used to select either line-to-neutral or lline-to-line voltage to the voltmeter. The nameplate is also marked to indicate the position of this switch. Nov 30/ Page 11

26 (d) Receptacle connector An Amphenol connector (12) provides a means of quickly disconnecting all wires to control box components. (e) Tray The tray (15) slides in and out on nylon rollers. It is secured in place by a twist-lock, screw fastener (8). (f) Manual voltage control When the automatic manual switch (11) is placed in MANUAL position, AC power is supplied to the rectifier (14) rather than to the automatic voltage regulator. The DC output of the rectifier is routed to the exciter field through a rheostat (13). The generator output voltage is thereby manually controlled by adjustment of the rheostat. Control Box Figure Nov 30/93 Page 12

27 (g) Excitation-deenergization relay The purpose of this relay (3) is to allow automatic excitation to be connected to the exciter field only when engine speed is being controlled by the electric governor. 1. Resistor (50 ohm, 100 watt) 9. Voltmeter 2. Resistor (25 ohm, 100 watt) 10. Frequency meter 3. Excitation-deenergization relay 11. Automatic-manual switch 4. Instruction plate 12. Receptacle connector 5. Line selector toggle switch 13. Manual voltage control rheostat 6. Meter selector rotary switch 14. Manual control rectifier 7. AC ammeter 15. Tray 8. Tray fastener 16. Flyback diode Generator Control Tray Figure 7 Nov 30/ Page 13

28 (2) Protective relay tray (see Figure 8) The bottom tray in the control box is identified as the protective relay tray and contains electrical and safety devices designed to protect the aircraft electrical system against damage which could result from overvoltage, undervoltage, overfrequency, or underfrequency. The tray also contains devices for the protection and control of the generator output electrical system. (a) Sensing modules The voltage sensing module (5) 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 (4) to trip open the load contactor holding circuit and disconnect output to the aircraft. A solid-state overload signaling device (Ref. 7, Fig 11) is also connected to the protective monitor module and performs a function similar to the voltage and frequency sensing modules. Trip values for these sensing modules are as follow: RELAY Overvoltage Undervoltage Overfrequency Underfrequency Overload TRIP POINT 130 V to 134 V 102 V or below 415 Hz to 425 Hz 390 Hz to 395 Hz Any value over 125% rated load capacity. See Para 6,H, (3) for more specific and detailed information regarding the overload device. For generator set operation wherein it is not desired that the underfrequency relay should trip instantly, this relay is available with an optional time delay circuit. This relay can be ordered with a timer on its PC board which times the trip to occur 5 seconds after an underfrequency condition occurs. For generator set operation wherein it is not desired that the overfrequency should trip instantly, the memory and time delay PC module (described in the following paragraph) can be orderedwitha5to6secondtimedelay. For generator set operation wherein it is not desired that the overvoltage relay should trip instantly, the memory and time delay PC module can be ordered with a 0.25 to 0.75 second time delay. (b) Memory and time delay module The memory and time delay module (4) 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 (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. Unless a generator set s protective circuitry is provided with a memory/time-delay board having optional timer circuits, such as are described in the preceding paragraph, 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. However, 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, 13, 14 and 15) which is turned on when a fault occurs. The module relay will remain energized (OPEN) and the light will remain ON until the reset switch (7) is pushed to break the module 12-V DC circuit, and allow the relay to return to normal, CLOSED position. 1-1 Nov 30/93 Page 14

29 (c) Indicating lights The function of these lights (10, 11, 13, 14 and 15) 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 (7) is pushed. All lamps in indicating lights may be tested by pressing switch (8). (d) Plug-interlock relay The function of the plug interlock relay (1) 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 (18) provides a means of by-passing the interlock relay (1) 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 (21) 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 (2) is to interrupt the load contactor holding coil circuit and remove the load in case of a blown fuse(17) in the protective relay coil circuit. (h) Connector A twenty-six contact connector (19) provides a quick-disconnect facility for all wiring to the tray electrical components so that the complete tray assembly may be removed quickly and easily. (k) Auxiliary underfrequency relay The function of the auxiliary underfrequency relay (3) is to automatically open the excitationdeenergization relay and disconnect the voltage regulator anytime generator frequency drops to 380 Hz or below. This protects the voltage regulator (Fig. 10) and ballast resistors (2, Fig. 7) against overload which could be caused by very 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. 9) in BUILD-UP-VOLTAGE position to restore generator voltage. Nov 30/ Page 15

30 1. Plug-interlock relay 12. Tray fastener 2. Fuse-interlock relay 13. Overfrequency indicating light 3. Auxiliary underfrequency 14. Undervoltage indicating light relay 15. Overvoltage indicating light 4. Memory and time delay module 16. Load contactor circuit fuse 5. Over-undervoltage module (2 A) 6. Over-underfrequency module 17. Protective system fuse (2 A) 7. Reset switch 18. Test bank switch 8. Light test switch 19. Receptacle connector 9. Hole plug 20. Terminal board 10. Overload indicating light 21. Resistor (100 ohm, 25 watt) 11. Underfrequency indicating 22. Tray light Protective Relay Tray Figure Nov 30/93 Page 16

31 F. Engine Control Panel (See Fig. 9) The engine control panel is mounted directly below the control box. In addition to 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 100 o Fto220 o F. (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. The 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 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. 9) 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 (18) 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. To check fuel quantity when engine is stopped, use switch (3) to turn ON panel lights. (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 (3, Fig. 7) contacts, to make three-phase, 115-V AC power available to the voltage regulator, or to the manual voltage control circuit for excitation of the generator exciter. Nov 30/ Page 17