Hobart 6824-1, 6824-2, 6824-3, 6824-4, 6824A-1 Operation And Maintenance Manual

...

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OM-499

Revised 053194

OPERATION AND MAINTENANCE

MANUAL

with

ILLUSTRATED PARTS LIST

for

ENGINE DRIVEN GENERATOR SETS

60-kVA, 400-Hz, 115/200-V AC, 3-Phase Units

with

PERKINS DIESEL ENGINE

Type 6.3544

SPECIFICATION MOUNTING VOLTAGE

REGULATOR 6824-1, 6824A-1 Trailer or Truck 430391C 6824-2, 6824A-2 Tractor 430391C 6824-3, 6824A-3 Stationary: With Fuel Tank & Batteries 430391C 6824-4, 6824A-4 Trailer or Truck, Dual Output 430391C

6824A-5 Trailer or Truck 489812 6824A-6 Tractor 489812 6824A-7 Stationary: With Fuel Tank & Batteries 489812 6824A-8 Trailer or Truck, Dual Output 489812

HOBART BROTHERS COMPANY

Airport Systems Group

Troy, Ohio 45373 U.S.A.

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Safety Instructions and Warnings for Electrical Power Equipment

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 attache 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.

a. 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.

1. 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 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 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.

(rather than by diesel or gasoline engines)

must be installed

(amperage)

May 31/94 Revised Safety Warnings

Page 1

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c. 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.

(1)

Before inspecting or servicing electrically-powered equipment, take the following precautions:

(2)

Shut OFF all power at the disconnecting switch or line breaker before inspecting or servicing the equipment.

(3)

Lock switch OPEN

(4)

Disconnect power to equipment if it is out of service.

(5)

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.

2. 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.

(or remove line fuses)

so that power cannot be turned on accidentally.

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.

3. 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.

4. 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.

5. 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.

Safety Warnings May 31/94 Revised Page 2

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.

6. Equipment Precautionary Labels

Inspect all precautionary labels on the equipment monthly. Order and inspect all labels that cannot be easily read.

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May 31/94 Revised Safety Warnings

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Safety Warnings May 31/94 Revised Page 4

Introduction

This manual contains operation and maintenance information for a series of 400-Hertz generator sets manufactured by Hobart Brothers Company, Power Systems Division, 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, “ 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,

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

(See 2-3, Para. B)”

refers to

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(See

May 31/94 Revised Introduction

Page 1

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Introduction May 31/94 Revised Page 2

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Table of Contents

SUBJECT CHAPTER/SECTION PAGE

Chapter 1. Description / Operation 1-1 1

Section 1. Description 1-1 1

1. General 1-1 1

2. Orientation 1-1 1

3. Special Features 1-1 1

a. “Roll-Out” Feature (Tow Tractor

-Mounted Unit) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1. . . . . . . . . . . . . . . . . 1i

b. Protective Monitor . . . . . . . . . . . . . . . . . . . . . . . . 1-1. . . . . . . . . . . . . . . . . . 2

c. Pull-out Trays . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . . 2

d. Voltage Regulator . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . . 2

e. Test Circuitry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1. . . . . . . . . . . . . . . . . . 2

f. Electric Governor . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . . 2

4. Identification 1-1 2

5. Canopy 1-1 5

6. Optional Equipment 1-1 5

a. Trailer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . . 5

b. Transformer-Rectifier . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . . 5

c. Truck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . . 5

d. Second Output and Control Box . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . . 5

e. Quick Start Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . . 5

7. Engine, Generator, and Controls Assembly 1-1 6

a. Basic Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . . 6

b. Engine Manufacturer’s Equipment . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . . 6

c. Hobart Engine Equipment . . . . . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . . 6

d. Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1. . . . . . . . . . . . . . . . . . 9

e. Control Box Assembly . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . . 9

f. Engine Control Panel . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . 15

g. Voltage Regulator . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . 17

h. Power Module Panel Assembly . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . 19

8. Test Box 1-1 23

a. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1. . . . . . . . . . . . . . . . . 23

b. Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . 1-1 . . . . . . . . . . . . . . . . . 23

9. Dual Output Units (Specifications 6824-4,

6824A-4 and 6824A-8) 1-1 24

May 31/94 Revised Table of Contents

Page 1

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SUBJECT CHAPTER/SECTION PAGE

Section 2. Preparation For Use,

Storage, Or Shipping 1-2 1

1. Preparation for Use 1-2 1

a. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 . . . . . . . . . . . . . . . . . 1

b. Inspection/Check . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 . . . . . . . . . . . . . . . . . 1

c. Installing Output Cables . . . . . . . . . . . . . . . . . . . 1-2 . . . . . . . . . . . . . . . . . 2

2. Preparation for Storage 1-2 3

. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 . . . . . . . . . . . . . . . . . 3

. Temporary Storage . . . . . . . . . . . . . . . . . . . . . . . . 1-2 . . . . . . . . . . . . . . . . . 3

. Long Time Storage (Over 30 Days) . . . . . . . . . . . 1-2 . . . . . . . . . . . . . . . . . 4

3. Preparation for Shipment (TractorMounted Units Only) 1-2 4

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. Cold Weather Engine Starting Procedures . . . . 1-3 . . . . . . . . . . . . . . . . . 4

d. Preparation for Power Delivery (Normal

Automatic Voltage Control) . . . . . . . . . . . . . . . 1-3 . . . . . . . . . . . . . . . . . 4

e. Power Delivery (Automatic Voltage Control). . . 1-3 . . . . . . . . . . . . . . . . . 5

f. Preparation for Power Delivery (Manual

Voltage Control) . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 . . . . . . . . . . . . . . . . . 6

g. Power Delivery (Manual Voltage Control) . . . . . 1-3 . . . . . . . . . . . . . . . . . 6

h. Discontinue Power Delivery . . . . . . . . . . . . . . . . 1-3 . . . . . . . . . . . . . . . . . 6

i. Stopping the Engine . . . . . . . . . . . . . . . . . . . . . . 1-3 . . . . . . . . . . . . . . . . . 6

3. Test Box Operation 1-3 6

4. Transformer-Rectifier Operation 1-3 8

a. Direct Current Power Delivery . . . . . . . . . . . . . . 1-3 . . . . . . . . . . . . . . . . . 8

b. Simultaneous 28.5-V DC and 115-V AC

Power Delivery . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 . . . . . . . . . . . . . . . . . 8

5. No. 2 Output Operation (Specifications 6824-4, 6824A-4 and 6824A-8) 1-3 9

a. Power Delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 . . . . . . . . . . . . . . . . . 9

b. Discontinue Power Delivery . . . . . . . . . . . . . . . . 1-3 . . . . . . . . . . . . . . . . . 9

6. Trailer Operation 1-3 9

a. Towing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 . . . . . . . . . . . . . . . . . 9

b. Parking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 . . . . . . . . . . . . . . . . . 10

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SUBJECT CHAPTER/SECTION PAGE

Chapter 2. Service 2-1 1

Section 1. Maintenance 2-1 1

1. General 2-1 1

2. Operation of Roll-Out Feature (For Tractor-Mounted Units Only) 2-1 1

a. Roll Generator-Set Out for Service . . . . . . . . . . . 2-1. . . . . . . . . . . . . . . . . . 1

b. Roll Generator-Set In to Normal Position . . . . . . 2-1. . . . . . . . . . . . . . . . . . 1

3. Inspection 2-1 1

4. Lubrication 2-1 3

a. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 3

b. Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 3

c. Generator Controls . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 3

d. Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 3

e. Starter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 4

5. Air Cleaner Service 2-1 4

a. Cartridge Removal. . . . . . . . . . . . . . . . . . . . . . . . . 2-1. . . . . . . . . . . . . . . . . . 4

b. Cartridge Installation . . . . . . . . . . . . . . . . . . . . . . 2-1. . . . . . . . . . . . . . . . . . 4

6. Engine Fuel 2-1 5

. Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 5

. Fuel Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 5

7. Engine Cooling System 2-1 6

a. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 6

b. Radiator Cap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1. . . . . . . . . . . . . . . . . . 6

c. Warm Weather Operation . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 6

d. Cold Weather Operation . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 6

e. Draining the Cooling System . . . . . . . . . . . . . . . . 2-1. . . . . . . . . . . . . . . . . . 8

f. Cleaning the Cooling System . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 8

g. Cleaning the Radiator Core . . . . . . . . . . . . . . . . . 2-1. . . . . . . . . . . . . . . . . . 8

h. Filling the Cooling System . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 8

8. Generator Maintenance 2-1 9

a. Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 9

b. Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 9

9. Drive Belts 2-1 9

a. Checking Belt Tension . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 9

b. Belt Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1. . . . . . . . . . . . . . . . . . 9

10. Trailer, Truck and Battery Maintenance 2-1 9

11. Service Helps 2-1 9

a. Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . . 9

b. Control Box Trays . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . 10

c. Generator Exciter . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . 10

d. Engine Control Panel . . . . . . . . . . . . . . . . . . . . . . 2-1 . . . . . . . . . . . . . . . . . 11

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Page 3

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SUBJECT CHAPTER/SECTION PAGE

Section 2. Inspection / Check 2-2 1

1. General 2-2 1

2. Engine 2-2 1

a. Fuel (See Fig. 1 for time schedules). . . . . . . . . . 2-2 . . . . . . . . . . . . . . . . . 1

b. Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 . . . . . . . . . . . . . . . . . 1

c. C. Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 . . . . . . . . . . . . . . . . . 1

d. V-Belts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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 . . . . . . . . . . . . . . . . . 3

4. Electrical System (115-V AC) 2-2 3

a. Monitoring Instruments . . . . . . . . . . . . . . . . . . . 2-2 . . . . . . . . . . . . . . . . . 3

b. Indicating Lights . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 . . . . . . . . . . . . . . . . . 3

c. Protective Modules . . . . . . . . . . . . . . . . . . . . . . . 2-2 . . . . . . . . . . . . . . . . . 3

d. Wiring and Connections . . . . . . . . . . . . . . . . . . . 2-2 . . . . . . . . . . . . . . . . . 4

5. Trailer and Truck 2-2 4

Section 3. Adjustment / Test 2-3 1

1. General 2-3 1

2. Test Panels 2-3 1

a. Generator Set Removed from Tractor . . . . . . . . 2-3 . . . . . . . . . . . . . . . . . 1

b. Generator Set in Tow Tractor . . . . . . . . . . . . . . . 2-3 . . . . . . . . . . . . . . . . . 1

3. Generator Set Test 2-3 2

a. Pre-operational Test Procedures . . . . . . . . . . . . 2-3 . . . . . . . . . . . . . . . . . 2

b. Operational Test Procedures . . . . . . . . . . . . . . . 2-3 . . . . . . . . . . . . . . . . . 3

4. Generator Set Adjustment 2-3 9

a. Generator Adjustment . . . . . . . . . . . . . . . . . . . . 2-3 . . . . . . . . . . . . . . . . . 9

b. Generator Control Adjustments . . . . . . . . . . . . 2-3 . . . . . . . . . . . . . . . . . 9

c. Basic Engine Adjustments . . . . . . . . . . . . . . . . . 2-3 . . . . . . . . . . . . . . . . . 12

d. Engine Accessories Adjustment . . . . . . . . . . . . 2-3 . . . . . . . . . . . . . . . . . 12

e. Electric Governor System Adjustment . . . . . . . 2-3 . . . . . . . . . . . . . . . . . 12

5. Generator and Exciter Test 2-3 17

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 . . . . . . . . . . . . . . . . . 17

6. Diode Test 2-3 17

7. Additional Test for Dual Output Unit 2-3 18

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SUBJECT CHAPTER/SECTION PAGE

Chapter 3. Troubleshooting Procedures 1 1

Section 1. Troubleshooting 3-1 1

1. General 3-1 1

a. Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 . . . . . . . . . . . . . . . . . . 1

b. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 . . . . . . . . . . . . . . . . . . 1

c. Use of the Troubleshooting Chart . . . . . . . . . . . . 3-1. . . . . . . . . . . . . . . . . . 1

2. Equipment for Troubleshooting 3-1 2

3. Safety 3-1 2

3. Parts Replacement 3-1 2

4. Test Values 3-1 2

5. Check Connections and Leads 3-1 3

6. Electric Governor Trouble Shooting 3-1 3

7. Engine Trouble Shooting Procedures 3-1 3

a. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1. . . . . . . . . . . . . . . . . . 3

8. Illustrations 3-1 3

Chapter 4. Illustrated Parts List 4-1 1

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

a. Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 . . . . . . . . . . . . . . . . . . 1

b. Parts List Form . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 . . . . . . . . . . . . . . . . . . 1

Section 2. Manufacturer’s Codes 4-2 1

1. Explanation of Manufacturer’s 4-2

(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

Section 4. Numerical Index 4-4 1

1. Explanation of Numerical Index 4-4 1

Chapter 5. Optional Equipment 5-0 1 Chapter 6. Manufacturer’s Literature 6-0 1 Unusual Service Conditions

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Table of Contents May 31/94 Revised Page 6

Chapter 1. Description / Operation

Section 1. Description

1. General

The basic generator sets Series No. 6824A. The various configurations of the set are identified by adding a dash number

suffix to the Series number.

etc.)

The generator sets in the 6824A series feature armatures 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.

The basic generator set which includes the engine, generator and all controls is identical for all models. Differences between models are those required by their respective mounting, such as trailer mounting, tow tractor mounting, etc. Identification of different models within the Series will be explained later in the Description.

Information and instructions throughout the manual apply to all models. Information which applies only to a certain model will be qualified and identified as such.

The purpose of the generator set is to generate and deliver regulated, 400-Hz electrical power to a parked generators are not running. The engine, generator, and controls are designed into a compact unit which is easily removable from a tow tractor. See Figure 2 for specifications and capabilities.

(or towed)

aircraft for operation of the aircraft’s electrical equipment when the on-board

(see Fig. 1)

covered by the manual are identified by Series No. 6824and

OM-499

(-1, -2,

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 as follows.

a. “Roll-Out” Feature (Tow Tractor-Mounted Unit)

For a generator set mounted on a tow tractor the generator set is supplied with two-channel-like tracks which are floor mounted in the generator compartment of the tow tractor. Tracks are equipped with cam-follower, needle-bearing rollers which support the generator set and allow it to roll in-and-out easily for servicing and maintenance.

Additional rollers are mounted on each side of the generator set main frame, near the rear, to add stability and to prevent the unit from tipping downward at the front when it is rolled outward for service.

May 31/94 Revised 1-1

(See Figure 21, Section 4-3.)

Page 1

OM-499

The set is secured in mounted position by two retaining brackets attached at the front of the unit

(See 2-1, Fig. 2).

approximately 38 inches, where a stop-bar on the main frame contacts a stop-block in the left track to prevent further outward travel.

b. Protective Monitor

A single, solid-state device 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.

c. Pull-out Trays

The control box is equipped with pull-out, drawer-type trays 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.

d. Voltage Regulator

A solid-state, adjustable voltage regulator aircraft (or distribution panel when applicable). The regulator is also adjustable for a variety of output cable sizes and lengths.

e. Test Circuitry

A receptacle connector 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.

The removal of two screws from the brackets allows the set to be rolled out

(4, Fig. 8)

(19, Fig. 9)

receives signals from all of the fault sensing units in the

(Fig. 6)

(Fig. 10)

with wiring to various test points throughout the electrical

provides automatic voltage regulation at the

which provide easy access to

f. Electric Governor

The engine is equipped with an all electric type governor kit equipment more fully described under the engine description.

(5 and 12, Fig. 3)

and other special

4. Identification

Generator sets are identified by their Specification number, which consists of a Series number plus a dash number set. For example, Specification number 6824A-2 identifies a machine designed for mounting on a tow tractor.

The following identification chart identifies in greater detail the machines covered by this manual.

SPECIFICATION No. CHARACTERISTICS 6824-1, 6824A-1, and

6824A-5 6824-2, 6824A-2, and

6824A-6 6824-3, 6824A-3, and

6824A-7 6824-4, 6824A-4, and

6824A-8

(i.e. -1, -2, etc.)

suffix. The suffix number indicates the mounting design of the generator

Designed for trailer or truck mounting. 12-V DC electrical power and fuel to be supplied from facilities on trailer or truck.

Designed for mounting on a tow tractor. 12-V DC electrical power and fuel to be supplied by tow tractor. Furnished with roll-out tracks for mounting on tow tractor.

Designed for stationary mounting. Equipped with two 12-V batteries and fuel tank.

Dual output unit for trailer or truck mounting. 12-V DC electrical power and fuel to be supplied from facilities on trailer or truck.

Generator Set Identification Chart

1-1 May 31/94 Revised Page 2

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1. Canopy 6. Mounting frame

2. Lifting eye 7. Engine fan exhaust deflectors

3. Windows 8. Engine exhaust pipe

4. Output receptacle cover 9. Radiator cap access cover

5. Output cable horn

May 31/94 Revised 1-1

Generator Set

Figure 1

Page 3

OM-499

PHYSICAL

Length Width 36 inches Height Weight

Output power rating 60 KVA Output voltage 115/200 VAC Rated load capacity 173 A Frequency/cycles per second 400 Hz Output Kilowatts 48 KW Power factor 0.8 PF Duty cycle 100% Operating speed 2000 RPM Overload capacity Output cable size 2/0

Overvoltage relay Trips 130 V to 134 V; resets 125 V Undervoltage relay Trips 93 V to 102 V; resets 110 V Overfrequency relay Trips 415 Hz to 425 Hz; resets 410 Hz Underfrequency relay Trips 375 Hz to 385 Hz; resets 385 Hz Undervoltage time delay 4 to 12 seconds, depending upon adjustment Overload relay Trips at 125% rated load in less than 5 minutes

(stationary units)

(overall)

(approximately)

GENERATOR CAPABILITIES

(125% of rated load)

GENERATOR PROTECTIVE SYSTEM

82 inches

(2082.8 mm) (914.4mm)

43 inches 3300 pounds

216 A

(1092.2mm)

(1496.8 kg)

ENGINE

Manufacturer Perkins Engines, Inc. Model T6-3544 Type In-line, 6-cylinder, 4-cycle diesel Displacement 354 cu. in. Compression ratio 16:1 Firing order 1 - 5 - 3- 6 - 2 - 4 Number of main bearings 7 Horsepower at 2000 RPM 107 Governed speed 2000 RPM + / - 4.5% Idle speed 850 + / - 25 RPM Electrical system 12 volt Oil Capacity Oil Capacity Coolant capacity Fuel Diesel oil conformint to ASTM Specification

(W/Filter) (W/O Filter)

(approx.)

15 Quarts 14 Quarts 20 quarts

D.975-66T, No. 1-D and 2-D MIL-L-2104B

Specifications and Capabilities

Figure 2

(5.8 liters)

(14 liters) (13.6 liters)

(19 liters)

1-1 May 31/94 Revised Page 4

OM-499

5. Canopy

A sheet metal enclosure, identified as a canopy and electrical controls. 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 an 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 a good flow of air. 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 where it passes over all windings before being discharged by the generator fan.

All generator sets in this Series except the tractor-mounted unit are equipped with a canopy having doors on both sides. Tractor-mounted units have two large removable panels on the right side mainly because the right side of the machine is not accessible when mounted on a tow tractor, and secondly because the thick doors would not allow mounting in the limited space available on the tractor. 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.

(1, Fig. 1),

provides protection for the engine, generator

6. Optional Equipment

Several items of optional equipment are available for units covered in this manual . Each piece of optional equipment 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. Trailer

A four-wheel trailer with batteries and fuel tank is available.

b. Transformer-Rectifier

(T-R)

A transformer-rectifier 115/200-V, 400-Hz, AC power from the generator and converts it to a 28.5 V DC output.

c. Truck

Trucks with special bodies for generator set mounting are available. Compartments in the body are provided for batteries, cable-storage, etc. Trucks available are Ford, Chevrolet, and GMC.

d. Second Output and Control Box

An auxiliary output and control box is available to provide a second independent 115-V AC output circuit. This option is for -1, -2 and -3 generator set specification numbers if a second output is desired for a machine purchased before dual output machines (-4 specification numbers) were available, or if a second output is desired for a tractor-mount or stationary unit.

e. Quick Start Kit

(See Section 1-3, Para. 2C)

is available for use with the generator set. This T-R receives

May 31/94 Revised 1-1

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OM-499

7. 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, turbo-charged Perkins Diesel 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 Perkins Shop Manual

(1)

Electronic stop control.

(2)

Fuel filter.

(3)

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:

(Chapter 6)

(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 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 instruction book in Chapter 6 for a detailed description. A brief description is given below:

(and generator output frequency)

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 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.

(5, Fig. 3)

is a box containing a compact assembly of solid state

c. Actuator

The actuator 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:

(12, Fig. 3)

supplies the force needed to move and position the fuel lever as

a. A heavy-duty motor starter b. Alternator with voltage regulator c. Starting switch d. Wiring harness

1-1 May 31/94 Revised Page 6

OM-499

1. Mounting frame 7. Voltage regulator 13. Output cable terminal board

2. Generator 8. Air cleaner 14. Engine control panel

3. Power module 9. Lifting yoke 15. Cable horn and clamp

4. Control box 10. Engine 16. Radiator

5. Governor control box 11. Engine exhaust pipe 17. Oil pressure switch

6. Starting fluid container * 12. Governor actuator * Optional

May 31/94 Revised 1-1

Generator Set Components

Figure 3

Page 7

OM-499

(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 normally closed switch opens and actuates the fuel valve solenoid which shuts down the engine.

(99 degrees C)

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

(69 kPa)

engine.

(4)

Air cleaner The diesel-engine air cleaner

eliminator and a service indicator. The indicator functions to signal the operator when the cartridge needs changing. A red cylindrical “flag” viewing chamber 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 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.

, this switch opens and actuates the fuel valve solenoid which shuts down the

(1)

when air pressure within the air cleaner housing drops below the outside

(18, Fig. 3)

(Fig. 4)

(unlocked)

. If the pressure in the lube oil system falls to 10 psi

is a dry-cartridge type. It is equipped with a moisture

(2)

is forced upward in a glass enclosed

by pushing the reset button

(3)

located on the bottom of

, this

1-1 May 31/94 Revised Page 8

Air Cleaner and Service Indicator

Figure 4

(5)

Exhaust system The exhaust system consists of a special noise reducing muffler

(2)

by a pipe and noise downward.

to a conventional exhaust manifold

(1)

. Baffles in the tail pipe outlet direct exhaust

(3, Fig. 5)

OM-499

which is connected

Noise Reduction Exhaust System

Figure 5

(6)

Radiator The radiator

disassembly for cleaning and repair.

d. Generator

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.

e. Control Box Assembly

The control box 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.

(16, Fig. 3)

(Fig. 6)

is a sheet metal enclosure which houses and provides mounting facilities

is a tube type with bolted-on, top and bottom tanks which permit

May 31/94 Revised 1-1

Page 9

OM-499

Control Box

Figure 6

(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 DC field circuit.

A variable resistor rheostat voltage range through which the rheostat can control generator output voltage.

(13)

(1)

is connected in series between the manual control rectifier

. Its purpose is to adjust the DC voltage to the rheostat and thus determine the

(2)

are connected in series in the generator exciter

(14)

b. Generator output monitors (meters)

The generator output is monitored by three instruments; a frequency meter

(9)

, and an ammeter

frequency of the generator output alternating current in the range of 380 to 420 Hz

per second)

. The voltmeter indicates the generator output voltage in each phase-to-neutral

(A-N, B-N and C-N)

switch (6) and the line selector switch 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 size and is graduated 0 to 500 A. The amperage value in each of the three phases may be read on the ammeter by selecting the desired phase with switch ammeter current transformers 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.

(7)

. The frequency meter is a resonant-reed type, and indicates the

or phase-to-phase

(A-B, B-C and C-A)

as selected by the meter selector

(5).(These switches will be described below.)

(Ref. 4, Fig. 11)

lower the output load current to a lesser

(10)

, a voltmeter

(6)

and

(cycles

The

. Three

1-1 May 31/94 Revised Page 10

OM-499

c. 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

(6)

or line-to-line. The meter switch under the switch knob, is marked and lettered to indicate the three functional positions of the meter switch.

(5)

is a twoposition, toggle switch used to select either line-to-neutral or lineto-line voltage to

the voltmeter. The nameplate is also marked to indicate the position of this switch.

(When the knob is pointing straight down, the switch is OFF.)

is a four-position, rotary type. A nameplate

d. Receptacle connector

An “Amphenol” connector box components.

(12)

provides a means of quickly disconnecting all wires to control

e. Tray

The tray fastener

(15)

slides in and out on nylon rollers. It is secured in place by a twist-lock, screw

(8)

f. Manualvoltage control

When the automatic manual switch supplied to the rectifier the rectifier is routed to the exciter field through a rheostat is thereby manually controlled by adjustment of the rheostat.

(14)

rather than to the automatic voltage regulator. The DC output of

(11)

is placed in MANUAL position, AC power is

(13)

. The generator output voltage

g. Excitation-deenergization relay

The purpose of this relay field only when engine speed is being controlled by the electric governor.

(3)

is to allow automatic excitation to be connected to the exciter

(4)

, located

The line switch

(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 protection and control of the generator output electrical system.

a. Sensing modules

The voltage sensing module 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 the aircraft. Trip values are adjustable, however, adjustments should be made ONLY under laboratory conditions.

A solid-state overload signaling device 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 Overload circuit trips at any value over 125% rated load capacity.

See Para 6,H, (3) for more specific and detailed information regarding overload device.

(5)

and frequency sensing module

(4)

to open the load contactor and disconnect output to

(Ref. 7, Fig 11)

(adjustable)

(6)

are connected to

is also connected to the protective

May 31/94 Revised 1-1

Page 11

OM-499

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

1-1 May 31/94 Revised Page 12

Generator Control Tray

Figure 7

OM-499

b. Memory and time delay module

The memory and time delay module 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 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. 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 Each of the five circuits is connected to a corresponding indicating light

15)

which is turned on when a fault occurs.

The module relay will remain energized

(7)

switch normal, CLOSED position.

is pushed to break the module 12-V DC circuit, and allow the relay to return to

(adjustable)

c. Indicating lights

The function of these lights 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 lamps in indicating lights may be tested by pressing switch

(10, 11, 13, 14 and 15)

(4)

is sometimes called the protective monitor module. It

(5 and 6)

will cause the time delay circuit to open the load contactor.

. All memory circuits are

(10, 11, 13, 14 and

(OPEN)

and the light will remain ON until the reset

is to indicate, to the operator, the

(7)

is pushed. All

(8)

d. Plug-interlock relay

The function of the plug interlock relay 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. Twentyeight-volt, direct current for operation of the relay is supplied from the aircraft either through an on-board transformerrectifier, 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.

(1)

is to cause the output load contactor to open in the

e. Test-bank switch

A spst, toggle switch supplying power to a load bank or to an aircraft not equipped with a plug interlock system.

(18)

provides a means of by-passing the interlock relay

(1)

when

f. Resistor

A 100-ohm, 25-watt resistor the relay in the event that phase C contacts in the load contactor should fail to close when the generator ON switch is operated.

(21)

is connected in series with the plug interlock relay to protect

g. Fuse-interlock relay

The function of the fuse-interlock relay and remove the load in case of a “blown” fuse

(2)

is to interrupt the load contactor holding coil circuit

(17)

in the protective relay coil circuit.

h. Connector

A twenty-six contact connector electrical components so that the complete tray assembly may be removed quickly and easily.

(19)

provides a quick-disconnect facility for all wiring to tray

May 31/94 Revised 1-1

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OM-499

1. Plug-interlock relay 12. Tray fastener

2. Fuse-interlock relay 13. Overfrequency indicating light

3. Auxiliary underfrequency relay 14. Undervoltage indicating light

4. Memory and time delay module 15. Overvoltage indicating light

5. Over-undervoltage module 16. Load contactor circuit fuse (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

1-1 May 31/94 Revised Page 14

Protective Relay Tray

Figure 8

OM-499

i. Auxiliary underfrequency relay

The function of the auxiliary underfrequency relay excitation-deenergization relay and disconnect the voltage regulator anytime generator frequency drops to 380 Hz or below. This protects the voltage regulator resistors 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.

f. Engine Control Panel (See Fig. 9)

This panel is mounted directly below the control box. In addition to engine controls and instruments, generator output controls are mounted here. A plexiglass 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

pressure gage

(2, Fig. 7)

(10)

. An hourmeter

against overload which could be caused by very high voltage regulator

(4)

(6)

records engine operating time.

a. Ammeter

The ammeter system. Its graduated range is from -60 A through 0 A, to +60 A.

(4)

indicates the direction and value of current flow in the 12-V DC electrical

(3)

is to automatically open the

(Fig. 10)

, a coolant temperature gage

and ballast

(8)

, and an oil

b. Temperature gage

The temperature gage 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

F to 220oF.

100

(8)

is a mechanical type of unit construction. It consists of a panel

c. Oil pressure gage and oil pressure switch

The oil pressure gage 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.

(10)

is a bourdon tube type and indicates engine lubricating oil

d. Hourmeter

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.

(6)

is electrically driven from the 12-V DC battery system. The hourmeter

e. Fuel gage and blocking diodes

An electric fuel gage 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 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

(2, Fig. 9)

(18)

is required in each power source circuit. One diode prevents energizing

accurately indicates the quantity of fuel oil in the tank

(3)

to turn ON panel lights.

May 31/94 Revised 1-1

Page 15

OM-499

(2)

Engine and generator controls

a. Engine-generator control switch

The engine-generator control switch

idle” switch)

BUILD-UPVOLTAGE, 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

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. In GENERATE position, power is maintained to the governor control box and to the excitation relay

. 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.

is a three-position toggle type. It is spring-loaded in one position,

b. Contactor control switch

This is another three-position, toggle switch 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.

(5) (also identified as the “build-up-voltage, generate,

(3, Fig.

(7, Fig. 9)

identical to the engine-generator

c. Instrument light and switch

A shielded, instrument panel light controlled by a toggle switch

(1)

is mounted at the left side of the control panel. It is

(3)

, which also controls instrument lights on the control box.

d. Engine starting circuit

The pushbutton start switch for closing an auxiliary solenoid switch. The auxiliary switch then connects 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 auxiliary solenoid switch is necessary because the start pushbutton switch is not capable of carrying the high amperage flow to the starter solenoid which would result if the starter gear and ring gear should fail to engage. The permissive toggle switch in the down

(STOP)

position.

(15)

and permissive toggle switch

(18)

also stops the engine when the toggle is placed

(18)

serve to connect power

e. Indicating lights

A green indicating light system. The light operates only when the engine is running and fuel pressure is sufficiently high to close a fuel pressure switch. The purpose of the pressure switch is to deactivate the protective circuit when the engine is stopped and prevent battery discharge.Another green indicating light power is available at the generator output terminal panel

(9, Fig. 9)

(14)

glows to indicate that power is available to the engine protective

glows when the generator output load contactor is CLOSED and

(13, Fig. 3).

f. Cold weather starting aid control

The push-pull control starting aid consists of a group of items designed to inject a highly volatile fluid into the engine air intake system to assist ignition of fuel when air temperature is too low for the heat of compression to ignite a normal fuel mixture. The starting aid consists of a cylindrical, fluid container and a valve operated by the control valve. Pushing the control IN forces fluid through a small tube and an atomizing nozzle into the inlet manifold. The addition of atomized, highly volatile fuel into the inlet air assists in igniting the diesel fuel mixture.

(11)

controls operation of a cold weather starting aid

(see 1-3, Fig. 4)

(11, Fig. 9)

which are mounted on the lifting yoke. The valve is

. Pulling the control outward allows fluid to flow into the

(Fig. 3).

The

1-1 May 31/94 Revised Page 16

OM-499

g. Fuse

A 10-ampere fuse light circuit, and 12-V DC system in the main generator protective system.

(3)

Air cleaner indicator The air cleaner indicator

function was explained in Para. 6, C,

(4)

Test receptacle connector This Amphenol connector

selected test points throughout the engine and generator electrical systems. Connections and schematic diagrams indicate points at which the leads are connected. The receptacle connector is designed to mate with a test box plug connector

Charging circuit resistor

(5)

This 0.5 ohm, 100 watt resistor allow the battery charging alternator to maintain a near normal voltage in the electric governor control box supply circuit when the TOW TRACTOR ENGINE is being started. Without this resistor in the circuit, cranking the tow tractor engine can cause a sufficient voltage drop in the system to influence operation of the electric governor control box and cause an overspeed condition which will cause the overfrequency relay to operate and shut off power to an aircraft. With the resistor in the circuit, alternator charging capability is limited to approximately 4 amperes at all times, and battery charging will be done mostly by the tow tractor generator or alternator.

g. Voltage Regulator

The voltage regulator compartment near the lifting yoke. On tractor and truck mounted units, or stationary units the regulator is accessible for adjustment by opening rear doors on the right side. On tractor mounted units, which have a large panel on the right side, the regulator is reached by removing the rear hood-type vent cover on top of the canopy.

Depending on specification number, the regulator used in a generator set may be either a magnetic amplifier type (Part No. 430391C) or a solid state regulator (Part No. 489812A). A seperate regulator manual is supplied with the generator set for each of these voltage regulators in Chapter 6 of this manual. A brief, working description is given here of the magnetic amplifier (mag-amp) regulator used with many Series 6824, Series 6824A, and Series 6824B GENERATOR SETS.

The voltage regulator is designed to provide 1% voltage regulation with .25second recovery time for all loads up to 100% of rated load on a threephase, four-wire, 115/200-volt, 400-Hz, brushless generator. This regulator provides field excitation power for the rotary exciter, and regulates generator output voltage by varying the exciter field power as required to meet varying load conditions. Thus, the generator output is held at a constant voltage. The maximum continuous rating of this regulator is 4.0 amperes at 140 volts DC.

Any deviation of the generator output voltage from its set, regulated level is sensed by the voltage detection and comparison circuits. A signal is fed from the comparison circuit into the transistorized pre-amplifier, amplified, and used to drive the magnetic amplifier. The magnetic amplifier output changes in response to this signal, changing the field power of the rotary exciter enough to return the generator voltage to its regulated value. The voltage at which the generator is regulated may be adjusted with the voltage adjustment rheostat

(13)

(12)

(Fig. 10)

protects the 12-V DC engine control circuit, hourmeter, illuminating

is mounted on the engine control panel for easy viewing. Its

(3) (see Fig. 6).

(19)

provides an attaching point for leads which are connected to

(see Fig. 12).

(20)

is required on tractor-mounted units only. Its purpose is to

is located on the right side of the machine just back of the engine

(2, Fig. 10)

May 31/94 Revised 1-1

Page 17

OM-499

1. Panel light 11. Cold weather starting aid control

2. Fuel gage 12. Air cleaner indicator

3. Light switch 13. Engine circuit fuse (10-A)

4. DC Ammeter 14. Engine “ON” indicating light

5. Engine-generator control switch 15. Engine starter switch

6. Hourmeter 16. (Deleted)

7. Load contactor control switch 17. Terminal board

8. Coolant temperature gage 18. Permissive start switch

9. Load contactor indicating light 19. Test receptacle

Engine Control Panel

Figure 9

1-1 May 31/94 Revised Page 18

OM-499

(1)

Voltage Regulator Controls The rheostat

Compensation for cable size is adjusted by a potentiometer for by adjustment of another potentiometer by a toggle switch under the potentiometer knobs indicates proper setting for various cable sizes and lengths. Regulator stability is adjusted by the damping circuit gain potentiometer time is adjusted by the damping circuit rate potentiometer knobs indicates proper setting for various cable sizes and lengths. Regulator stability is adjusted by the damping circuit gain potentiometer

(2, Fig. 10)

(8).

(10).

(2)

Components (see Fig. 10) Components of the basic circuits are mounted in two major subassemblies which are the line

drop compensation chassis assembly

(15).

Receptacle connectors interconnecting wire leads. The two subassemblies are mounted on a chassis other main components of the regulator, which include a resistor

(2),

fuse

(12)

and fuseholder Field ballast resistors and line drop current transformer loading resistors are located at a point remote from the voltage regulator and are supplied with the regulator. The two field ballast resistors are located in the generator control tray are located on the power module panel assembly

Protection

(3)

Internal circuitry of the welding regulator is protected by a cartridge type 5-ampere fuse.

h. Power Module Panel Assembly

The power module panel assembly located at the right rear of the machine behind the control box. On all models except the tow tractor mounted unit, it is accessible by removing rear access-vent cover panel assembly provides sensing and overload protection for the output circuit and provides a means of connecting and disconnecting generator output to and from the load

is used to adjust the regulated voltage value of the generator output.

(4).

Cable length is compensated

(3).

Cable compensation may be turned ON or OFF

(5).

For this application the switch must always be ON. An instruction plate

(8)

. Regulator response

Regulator response time is adjusted by the damping circuit rate potentiometer

(6),

and the sensing and pre-amplifier chassis assembly

(7, 9, and 11)

(13),

nineteen-pin, receptacle connector

provide quick connect-disconnect facilities for

(18)

along with

(1),

voltage adjusting rheostat

(14),

and reactor

(Ref. 2, Fig. 7).

Transformer loading resistors

(Ref. 8, Fig. 11).

(Fig. 11)

sometimes referred to as the “contactor panel”, is

(2, Fig. 1)

on the canopy. The

(aircraft).

(17).

Load contactor

(1)

The load contactor 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

NOTE: This contactor may be replaced by the old style contactor used in previous 60-KVA machines. This

note is for the benefit of those users who may have old style contactors Part number 75GH-566 (Hartman No. A-874C) in stock.

(2)

Current transformers

(6, Fig. 11)

(3, 4, and 9).

is a sealed unit which contains a magnetic operating coil and four

a. Ammeter current transformers

Three current transformers

(250-A to 5-A)

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.

which will operate the ammeter

(4)

lower the output load current to a lesser value of definite ratio

(4, Fig. 9)

movement without damage. The

May 31/94 Revised 1-1

Page 19

OM-499

1. Resistor (1000 ohms, 25 watts) 10. Damping circuit rate potentiometer

2. Regulator rheostat 11. Receptacle connector

3. Cable length compensation rheostat 12. Fuse (5 amp)

4. Cable size compensation rheostat 13. Fuseholder

5. On-off switch, line drop 14. Receptacle connector compensation 15. Sensing and preamplifier chassis

6. Line drop compensation chassis assembly 16. High-phase sensing board assembly

7. Receptacle connector 17. Reactor

8. Damping circuit gain potentiometer 18. Chassis

9. Receptacle connector 19. Terminal board

1-1 May 31/94 Revised Page 20

Voltage Regulator (Part No. 430391C)

Figure 10

OM-499

b. Line-drop current transformers

The three line-drop current transformers 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

Manual No. TM-232).

c. Overload current transformers

Three overload current transformers output load current in each of the three output phases, and supply a reduced value current signal to the overload module

(3)

Overload module The overload module

(3)

and to send a signal to the protective monitor module 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 hermeticallysealed, reed-type relay. Relay contacts are normally open. The solidstate 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 protective monitor and interrupts the load contactor holding circuit, allowing the load contactor to open.

The following is a list of overload module characteristics:

NOTE: The overload protective system will function when any phase carries 123% to 127% of rated

load.

(7)

is a solid-state device designed to interpret a signal from transformers

(7).

(9),

in conjunction with burden resistors

(see Voltage Regulator

(3),

in conjunction with burden resistors

(4, Fig. 8)

when an overload condition

(silicone-controlled rectifier)

(8),

(1),

monitor the

in the

detect

• 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.

NOTE: All times are plus or minus 25% and are nonadjustable.

(4)

Rectifier A diode-bridge rectifier

converts it to a pulsating, direct current for energization of the load contactor holding 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 holding coil, hence, the load contactor opens.

(5)

Terminal boards Three terminal boards

(5)

receives 400-Hz AC from phase C of the generator output an

(2)

provide connection facilities for small leads.

May 31/94 Revised 1-1

Page 21

OM-499

1. Overload resistor (25 ohm, 25 watt) 6. Load contactor

2. Terminal board 7. Overload module

3. Overload current transformer 8. Line drop resistor 50 ohm, 25 watt

4. Ammeter current transformer 9. Line drop current transformer

5. Rectifier 10. Blocking diode

1-1 May 31/94 Revised Page 22

Power Module Panel Assembly

Figure 11

8. Test Box

The test box is an optional accessory item used for testing the generator set. All generator sets are wired to accommodate a test box, however, the box is supplied only when ordered

388318A-1).

a. Description (See Fig. 12)

The test box assembly consists of a rotary selector switch, momentary contact pushbutton switch, and two, insulated-tip test jacks, mounted in a small metal box. Connection to the generator set is made through a wiring harness equipped with a 26-contact plug connector which mates with a receptacle connector.

b. Theory of Operation

Wire leads are connected to the electrical circuitry of the generator set at various points and routed to a receptacle connector, mounted on the engine control panel. They are connected to the test box rotary switch by a plug connector and wiring harness.

The rotary selector switch is wired in such a manner that for any switch position, two pre-selected test points in the generator set circuitry are connected for testing. The selector switch may be rotated to any one of 22 positions, however not all positions are used in this installation. An instruction plate mounted under the switch knob indicates switch positions and component tested in each position. Normal voltage for each test is also indicated.

Two test jacks are provided for connection of the test prods of a voltmeter. After the voltmeter is connected and selector switch positioned, the test circuit is closed by pressing the pushbutton switch. A voltage value may then be observed on the voltmeter. This arrangement prevents energization of test circuitry and equipment for extended periods and allows the operator to reset and adjust the voltmeter without disconnecting it from the box.

For operating instructions, see Sect. 1-3, Para. 3.

(Part Number

OM-499

May 31/94 Revised 1-1

1. Test box

2. Cable

3. Plug connector

Test Box Assembly

(Optional)

Figure 12

Page 23

OM-499

9. Dual Output Unit (Specification 6824-4)

This generator set has two output circuits for servicing two aircraft simultaneously, or for servicing a single aircraft with two input receptacles.

The output terminal boards for this unit are arranged as illustrated in Figure 13, with output No. 1 at the rear, lower terminal board and output No. 2 at the front, upper terminal board. This dual output assembly is mounted in the same location as the single output terminal board on the single output unit

(13, Fig. 3).

The output cable clamp for the No. 2 output is mounted next to the cable clamp for the No. 1 output, just to the left fo it, as viewed from the side of the unit. See Fig. 13.

The contactor switch of the second output is located on the control nameplate of th engine control panel. See Fig. 14. Located beside this switch is the No. 2 contactor closed light, which glows green when the No. 2 contactor is closed. These parts are identical to items 7 and 9 on Fig. 9.

The power module panel for output No. 2 module panel for output No. 1. identical to items 6, 5, and 10, Figure 11. The two relays, TEST BANK switch and resistor are identical to items 1, 2, and 21, Figure 8.

The protective circuits described in Para. E. output No. 1.

(See Fig. 16).

(Fig. 13)

is mounted on brackets directly above the power

The load contactor, rectifier and blocking diode are

(2) (a)

and

(b)

monitor and protect output No. 2 as well as

1-1 May 31/94 Revised Page 24

Dual Output Terminal Boards

Figure 13

OM-499

No. 2 Output Control

Figure 14

May 31/94 Revised 1-1

No. 2 Power Module

Panel

Figure 15

Page 25

OM-499

This page intentionally left blank.

1-1 May 31/94 Revised Page 26

OM-499

Section 2. Preparation For Use, Storage, Or Shipping

1. Preparation for Use

a. General

These instructions are based on the assumption that the tow tractor mounted unit is properly installed on the tractor and that all necessary fuel and electrical connections have been made. Hobart Brothers Company does not build an aircraft tow tractor. Generator sets for tractor mounting are installed by the customer, or tractor manufacturer. Other generator sets, when ordered with truck or trailer, are mounted at the Hobart factory and are shipped in running condition and ready for operation after inspection and check.

WARNING

Improper operation can kill, injure, or cause damage! Read and understand

operating instructions in section 1-3 before operating the unit.

b. Inspection/Check

Inspect the unit thoroughly prior to operation.

(1) (2) (3)

(4)

(5) (6)

CAUTION

Remove blocking, banding, ties, and other securing material. Inspect exterior for shipping damage such broken lights, damaged sheet metal, etc. Open all canopy doors and inspect interior for foreign material such as rags, tools, shipping

papers, etc. 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.

Check security of tractor mounted generator set retaining components Check the following for sufficient quantity:

Fuel

Turn ON panel lights to energize fuel gage when engine is stopped.

are supplied from the tow tractor tank.) 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.

Be sure the cooling system antifreeze solution is adequate to protect below lowest temperature expected.

(Sect. 2-1, Fig. 2).

(Tractor-mounted units

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 Perkins Shop Manual for oil

recommendations.

May 31/94 Revised 1-2

Page 1

OM-499

(7)

Check air cleaner The air cleaner

other material covering the air inlet area.

c. Installing Output Cables Units are generally shipped without generator set-to-aircraft cables.

NOTE: Generator sets designed for tractor mounting are equipped with a generator output receptacle

connector. No output cable wiring is required. An output cable assembly with plug connector on each end is required for tractor-mounted machines (see 1-1; 12, Fig. 3).

(1)

Three-phase, AC output cable assembly installation The AC output terminal panel is located on the left side, below the air cleaner and left of the

engine control panel

(Sect. 1-1, Fig. 3, item 8)

(see Fig. 1).

a. Open left rear canopy doors and loosen cable clamp screws at cable horn (see 1-1; 13, Fig.

3).

b. Route cables through cable horn and clamp and upward to terminal board.

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.

c. Each terminal stud is identified by an identification plate. Each cable should be identified by

a band-type marker. Connect cable “A” to terminal “A”, “B” to “B”, etc. Tighten terminal nuts securely. Connect small plug interlock lead “E” or “F” to terminal “E” or “F”.

is a “dry” type. Be sure there are no papers, tapes, or

d. Tighten clamp screws securely, but avoid damage to cable insulation.

AC Output Terminal Panel

Figure 1

1-2 May 31/94 Revised Page 2

(2)

Transformer-rectifier cables as illustrated in Figure 2. Use 4/0 size cables.

(DC)

output cable installation

(optional equipment)

OM-499

. Install DC output

T-R Output Cable

Installation

Figure 1

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.

May 31/94 Revised 1-2

Page 3

OM-499

(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.

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 engine once each week.

a. Make certain the cooling system is adequately protected. b. Start the engine and operate at a fast idle (800 to 1000 RPM) until coolant temperature has

WARNING

(2)

(3)

reached at least 140 deg F.

Make certain of adequate ventilation before starting the engine.

c. Operate normal operating controls.

If weekly operation is not possible, prepare and protect the engine in accordance with instructions in Perkins Diesel Operator’s Manual.

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.

3. Preparation for Shipment (Tractor-Mounted Units Only)

During long shipments by rail (and other) the generator set retaining hardware may become loosened by vibration, jolting, etc.

CAUTION

When shipping the unit (mounted in a tow tractor), provide additional retaining materials to make certain the generator set cannot roll out of the tow tractor.

NOTE: It is suggested that strong banding may be used to secure the generator set, or a strong steel bar

may be welded or bolted across the front of the generator set frame.

1-2 May 31/94 Revised Page 4

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 necessary when working in close proximity to this equipment. Read and follow all of the operating instructions before attempting to operate the equipment.

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.

OM-499

(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

NOTE: This switch must be ON to check fuel when engine is stopped.

(2)

Hold engine start switch

(28)

pushbutton engine start switch Release switch

(3)

Check ammeter

(4)

Check fuel gage

(5)

Place engine generator control switch

(6)

Activate generator output contactor switch

to crank engine. When engine starts, release pushbutton. Continue to hold

(30).

(17)

(15)

(30, Fig. 1)

(30)

in position until oil pressure gage

for charge reading.

and oil gage

in START position momentarily. Push engine start

(23).

(16)

in ON position

(18)

in IDLE position.

(20).

(23)

reads at least 20 PSI pressure.

May 31/94 Revised 1-3

Page 1

OM-499

1. Frequency meter 12. Protective relay tray 22. Load contactor indicating light

2. Voltmeter r 13. Instrument panel light 23. Oil pressure gage

3. Fastener 14. Generator control tray 24. Cold weather starting aid control

4. AC Ammeter 15. Fuel gage 25. Air cleaner indicator

5. Meter switch 16. Light switch 26. Engine circuit fuse (10-A)

6. Line switch 17. DC Ammeter 27. Engine protective circuit

7. Reset switch 18. Engine-generator indicating light

8. Light test switch control switch 28. Engine starter switch

9. Fault indicating lights 19. Hourmeter 29. Blocking diodes

10. Contactor circuit fuse (2-A) 20. Load contactor control switch 30. Permissive start switch

11. Protective system fuse (2-A) 21. Coolant temperature gage 31. Test receptacle connector

1-3 May 31/94 Revised Page 2

Operating Controls and Instruments

Figure 1 (Sheet 1 of 2)

OM-499

32. Manual voltage control rheostat 38. Cable length compensation

33. Automatic-manual voltage control rheostat switch 39. Cable size compensation

34. Test bank switch rheostat

35. Light test switch 40. Line-drop compensation on-off

36. Reset switch switch

37. Automatic voltage control 41. Fuse (5-A)

May 31/94 Revised 1-3

Operating Controls and Instruments

Figure 1 (Sheet 2 of 2)

Page 3

OM-499

c. Cold Weather Engine Starting Procedures

A cold weather starting-aid kit below 50 degree F. To start the engine, using the starting aid, proceed as follows:

(1)

Position switches and controls as instructed in steps Engine Starting Procedures, above.

(2)

Prepare starting aid for use. The starting aid is shipped in a safe condition and is not operable until assembled. Assemble as follows:

WARNING

Fires, fumes, and flying parts can kill or injure! Starting fluid is extremely flammable. It is under pressure. Use caution when handling. Avoid contact with skin and avoid breathing vapor.

a. Loosen clamp screws (1, Fig. 2) and slide the cylinder (2) upward sufficiently to remove

protective cap (3) and plug (4). b. Use bottle opener to remove cylinder cap (3). Unscrew and remove plug (4). c. Slide the cylinder (2) downward and thread into the valve (5). Tighten securely. The starting

aid is now ready to use.

Cold weather starting procedures are exactly the same as for normal starting except:

(3)

(Fig. 2)

is provided to assist in starting the engine at temperatures

(1)

through

(4),

paragraph B, Normal

a. Before cranking the engine, pull the starting aid control (24, Fig. 1)

its travel. Hold for 2 to 3 seconds. (This allows the starting aid valve chamber to fill with

pressurized ethyl ether.) b. Push the control

IN.

(This step sprays starting fluid into the engine intake manifold.) c. Push starter switch (28) to crank engine. d. Follow normal starting procedures and

CAUTIONS

above [steps (5) through (7), para. 2, B].

e. In extremely cold weather it may be necessary to repeat steps (a) and (b) above.

CAUTION

Use starting aid only for starting. Do not operate while engine is running.

WARNING

Do not “flood” the engine with starting fluid. A serious explosion could result.

d. Preparation for Power Delivery (Normal Automatic Voltage Control)

The following are power delivery preparation procedures to be followed after the engine is started.

(1)

Check and position switches and controls.

a. Loosen fastener (3, Fig. 1) and pull generator control tray outward. Place automatic-manual

switch (33) in

b. Loosen fastener (3) and pull protective relay tray outward. Place test bank switch (34) in

AIRCRAFT

system. (If not, place in TEST BANK position.) Slide tray in and secure.

AUTOMATIC

position. Close tray and secure.

position if the aircraft being serviced is equipped with 28.5-V DC interlock relay

OUT

to the full extent of

c. Meter switch (5) may be in any position except pointing straight

(2)

Connect output cable plug connector to aircraft receptacle. Be sure connectors are mated fully and securely.

1-3 May 31/94 Revised Page 4

DOWN.

OM-499

1. Clamp screw

2. Fluid cylinder

3. Cap

4. Plug

5. Valve

Cold Weather Starting Aid

(Optional)

Figure 2

e. Power Delivery (Automatic Voltage Control)

(1)

Place engine-generator control switch momentarily, then allow it to position itself in GEN position. The electric governor will immediately increase engine speed to 2000 RPM and maintain it.

(2)

Observe generator instruments. Frequency meter

(2)

Voltmeter

(3)

The final step in delivering power is closing the load contactor. When satisfactory frequency and voltage values are indicated by the instruments, close the load contactor by momentarily placing the load contactor control switch indicating light is available at the aircraft. As soon as the light glows, release the switch. It will automatically return to the center ON position.

NOTE: If the indicating light (22) should “go-out” as soon as the switch is released, and no fault lights are ON,

it indicates that 28.5-V DC holding current is not being supplied from the aircraft to the plug-interlock relay. Correct the condition an again operate the load contactor control switch (20) as above.

(4)

It is recommended that the operator check output voltage and current in each of the three phases early in the power delivery run. Use the meter switch line switch operating practice to observe the instruments until load conditions stabilize.

should indicate 115 V AC when line switch

(22)

should glow at once to indicate that the load contactor is closed and power

(6)

to select line-to-line or line-to-neutral voltage. If the load is changing, it is good

(20)

(18, Fig. 1)

in the top

in BUILD-UP-VOLTAGE position

(1, Fig. 1)

(spring loaded),

should indicate exactly 400 Hz.

(6)

is in LINE-TO-NEUTRAL position.

CLOSE position. The green

(5)

to select the phase. Use the

May 31/94 Revised 1-3

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OM-499

(5)

A condition of overvoltage, undervoltage, underfrequency, overfrequency, or overload in the output circuit will automatically open the load contactor and turn on the applicable indicating light to signal the operator which of the above faults caused the protective monitor system to operate. After the fault has been corrected, press the reset switch light and reset the protective relay system. Proceed with power delivery by operating the load contactor switch.

f. Preparation for Power Delivery (Manual Voltage Control)

Preparation for power delivery using manual voltage control is exactly the same as for automatic

(1)

thru

(2)

control [Para. 2, D,

(1)

Place automatic-manual switch

(2)

Set the manual voltage control rheostat

g. Power Delivery (Manual Voltage Control)

Power delivery using manual voltage control is the same as automatic delivery [Para. E, (1) thru (5) above] except:

(1)

Control generator output voltage by adjusting the rheostat reading on the voltmeter and COUNTERCLOCKWISE to DECREASE voltage.

(2)

Adjust voltage to 115 V AC.

above] except:

(33)

in MANUAL position.

(2).

Turn the rheostat

(32)

(7)

to turn off the indicating

near its mid-range position.

(32)

to maintain a steady 115-V AC

(32)

knob CLOCKWISE to INCREASE voltage

(3)

During manual power delivery the operator must remain with the generator set to adjust output voltage for varying loads and conditions.

h. Discontinue Power Delivery

(1)

Place the load contactor switch immediately to indicate that the load contactor has opened and power is no longer being delivered to the aircraft.

(2)

Place engine-generator control switch

(20)

in OFF position. Green light

(18)

in IDLE position.

(22)

should go OFF

WARNING

HIGH VOLTAGE - Electric shock or fire can kill! Never disconnect the output cable while power is being delivered.

(3)

Disconnect output cable from aircraft.

i. Stopping the Engine

(1)

Allow the engine to idle a few minutes before stopping, to permit cooling.

(2)

To stop the engine, move the START-RUN-STOP switch

(30)

to the STOP

(down)

position.

3. Test Box Operation

The test box is useful and convenient in testing the generator set after repair or overhaul and also in trouble shooting. To operate the test box, proceed as follows:

1-3 May 31/94 Revised Page 6

OM-499

a. Open left, rear canopy doors and connect the test box plug connector

the test receptacle connector

b. Connect the test prods of a voltmeter at the test jacks

coded. RED indicates POSITIVE. BLACK indicates NEGATIVE.

c. Locate the component or circuit to be tested in the DESCRIPTION column on the instruction

plate and set the selector switch

d. Note the normal voltage value and kind of current

and set voltmeter accordingly.

e. Comply with conditions indicated in CONDITIONS column for the particular test being

performed.

f. Press the pushbutton switch

normal voltage indicated in VOLTAGE column. g. Release pushbutton switch. h. Repeat steps A thru G for other test as required. i. J. When test are completed, disconnect the test equipment and close canopy doors.

(Fig. 4).

(3 and 4, Fig. 3).

(1, Fig. 3)

(2)

and observe voltage indicated by the voltmeter. Compare to

to the number indicated opposite the description.

(AC or DC)

to be expected at the position

(see 1-1; 3, Fig. 14)

Test jacks are color

1. Selector switch

2. Pushbutton switch

3. Positive test jack (red)

4. Negative test jack (black)

5. Instruction plate

Test Box Operating

Controls

Figure 3

May 31/94 Revised 1-3

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OM-499

Test Receptacle

Connector

Figure 4

4. Transformer-Rectifier Operation

Transformer-Rectifier operating instructions are contained in its operating manual, however some generator set instructions are required here.

a. Direct Current Power Delivery

NOTE: If the customer adds a Transformer-Rectifier to a standard machine which was NOT equipped with

aT-Rwhenitleftthefactory,hemustremovethejumperlead which will befoundonthesmallterminal strip in the generator set voltage regulator installed T-R, the jumper will have been removed.

(1)

When delivering power from a T-R, prepare the generator set for DC power delivery the same

as for AC delivery, except do not connect AC output cable and do not close AC load contactor

(see Para. 2, D

(2)

For T-R operating instructions, see Hobart Manual No. OM-433.

b. Simultaneous 28.5-V DC and 115-V AC Power Delivery

If both 28.5-V DC and 115-V AC must be delivered at the same time, the following rules and precautions

(1)

Place T-R current limiting switch in OFF position. This will eliminate the soft start feature of the T-R, but will prevent AC voltage from dropping low enough to trip the AC load contactor.

(2)

Line-drop compensation on the T-R must be REDUCED or turned DOWN completely to prevent opening of the AC load contactor by an overvoltage condition. Readjust T-R line-drop compensation so that AC voltage 118-V AC when the DC load is 500 Amperes. If higher DC voltage is needed, adjust T-R line-drop compensation as required.Observe AC voltage while making this adjustment to be certain that it does not go TOO HIGH with DC load.

must be observed.

and E).

(Optional Equipment) (See Fig. 5)

(see 1-1; 19, Fig. 12).

(as indicated by the generator set voltmeter)

If your generator set has a factory

does not exceed

(3)

During simultaneous, continuous operation, loads on either circuit are limited only by the capacities of their respective circuits, however, the combined loads should not exceed the rated capacity of the generator set

1-3 May 31/94 Revised Page 8

(90 KVA or 72KW).

Transformer-Rectifier

Figure 5

OM-499

5. No. 2 Output Operation (Specifications 6824-4, 6824A-4 and 6824A-8))

Each output of the dual output machines may be operated independently of the other. Each output has the same rating as the generator when operated alone; however, when operated simultaneously, the total load of both circuits should not exceed the rated capacity of the generator.

a. Power Delivery

Output No. 2 on the dual output machines is operated in the same manner as output No. 1

para. 2)

closed, the contactor CLOSED light beside that switch will glow green.

NOTE: Make sure that No. 2 TEST BANK switch (1-1; Fig. 15) is positioned properly (see para. D. 1. (b) for

proper position).

b. Discontinue Power Delivery

To open the load contactor in the No. 2 output circuit, place the No. 2 contactor switch OFF position. The indicator light beside the switch will go out. For engine shutdown procedures, refer to para. 2. H. For generator sets having the TO-128 in Chapter 6.

using the duplicate contactor switch shown in Figure 6. When the No. 2 contactor is

(Fig. 6)

optional second output, refer to Hobart Manual

(see

6. Trailer Operation

a. Towing

Observe the following rules when towing the trailer.

(1)

Be sure all output cables are disconnected and properly stowed.

(2)

Be sure parking brake is released.

(3)

Avoid turns which are shorter than the steering linkage will freely allow.

(4)

Avoid dangerous speed and sudden turns.

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OM-499

b. Parking

Observe the following rules when parking the trailer.

(1)

Apply parking brake before disconnecting tow vehicle.

(2)

Always place drawbar in an upright, vertical position when trailer is parked.

No. 2 Output

Control

Figure 6

1-3 May 31/94 Revised Page 10

Chapter 2. Service

Section 1. Maintenance

1. General

To make certain the generator set is always ready for operation, it must be inspected and maintained regularly and systematically so that defects may be discovered and corrected before they result in serious damage or failure of the equipment.

WARNING

Electric shock, flying parts, or fire can kill or injure! Stop operation immediately if a serious or possibly dangerous fault is discovered.

OM-499

2. Operation of Roll-Out Feature (For Tractor-Mounted Units Only)

One of the first things to learn about the service operation is how to roll the generator partially out of the tow tractor so that components on the right side and bottom of the unit are more accessible.

a. Roll Generator-Set Out for Service

(1)

Make CERTAIN the stop-bar

(2)

Remove two each attaching nuts, screws, and lockwashers

(2)

at the front of the machine.

(3)

Roll the generator set outward carefully, until the stop-bar the left track. This will allow access to the right side and underside of the engine.

b. Roll Generator-Set In to Normal Position

To return the generator-set to normal operating position, proceed as follows:

(1)

Roll the machine inward carefully until the retaining brackets gussets in the tracks.

(2)

Install attaching screws, nuts, and lockwashers and tighten securely.

(Figure 1)

is down as far as it will go in SAFETY position.

(1, Fig. 2)

(Figure 1)

(2, Figure 2)

from retaining brackets

contacts the stop-block in

contact the end

3. Inspection

A periodic inspection should be established and maintained. A suggested inspection/check schedule is provided in 2-2, Figure 1, however it may be modified as required to meet varying operating and environmental conditions. If the generator set is mounted on a tow tractor, it is suggested that inspections be coordinated.

May 31/94 Revised 2-1

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OM-499

Roll-out Stop-bar (For tractor-mounted units only)

Figure 2

1. Attaching hardware; nuts, screws, and lockwashers

2. Retaining brackets

2-1 May 31/94 Revised Page 2

Generator Set Retaining Components

(Tractor-mounted units only)

Figure 2

4. Lubrication

a. General

Proper lubrication is one of the most important steps in good maintenance procedures. Proper lubrication means the use of correct lubricants and adherence to a proper time schedule. Frequency of lubrication and recommended lubricants are indicated in Figure 3.

b. Generator

The 400-Hz generator requires NO lubrication. The rotor is supported by two ball bearing assemblies which are lubricated and sealed at the factory for lifetime, maintenance-free operation. It is suggested that generator bearings be checked after 5000 hours of operation.

c. Generator Controls

Generator controls and instruments require no scheduled periodic lubrication. A few drops of oil may be required on door hinges occasionally to insure free an quiet operation.

d. Engine

Although the engine and its accessories require no more attention than any other similar installation, they still inherently require a major portion of the generator set lubrication and maintenance. Recommendations regarding engine lubrication have been taken from the engine manufacturer’s “Operator’s Manual” and incorporated here to make them more readily available to operators and maintenance personnel.

OM-499

(1)

Lubrication schedule Time schedules indicated on the Lubrication Chart, Fig. 3, are approximate. They are based on

average operating conditions. It may be necessary to lubricate more frequently under severe operating conditions such as: low engine temperatures, excessively heavy loads and high oil temperatures, or intermittent operation. However, time intervals should not exceed those indicated in the chart without careful evaluation.

(2)

Oil specification Oil recommended by the engine manufacturer is identified by a military specification number,

MIL-L-2104B. Because of the substantial increase in additive concentration in some MIL-L-2104B oils to meet service “MS” requirements, recommended oil is qualified still further by the following limitations

a. Zinc, as zinc diorganodithiophosphate, between a minimum of 0.07 and a maximum of 0.10

percent by weight.

b. Sulfated ash (ASTM D-874) of 1.00 percent maximum by weight, except lubricants that

contain only barium detergent-dispersants where 1.50 percent by weight is allowed.

Diesel lubricating oil specifications are discussed in the Perkins Diesel Handbook for Diesel Engines.

(3)

Oil viscosity The use of an SAE-30 grade oil is recommended for year-round service. The engine is

equipped with an ether starting aid to assist in engine starting during cold weather when SAE-30 oil is used. Multigrade oils are NOT recommended, and should be considered only as a “last resort” to facilitate engine starting.

(4)

Changing engine oil Change engine lubricating oil following the instructions in the Perkins Engine Shop Manual

(Chapter 6).

(5)

Changing engine oil filter Change the oil filter following the instructions in the Perkins Engine Shop Manual (Chapter 6).

Lube oil capacity for this engine is 15-1/2 quarts.

May 31/94 Revised 2-1

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OM-499

ITEM MAINTENANCE REQUIRED Lubricating Oil Check oil level daily or after every 10 hours of use. Change oil after 200

Lube Oil Filter Change oil filter every 200 hours or one month of use. Fuel Oil Filter Drain filter daily. Change filter element every 800 hours or 6 months of use. Starter Lubricate as needed, using heavy duty engine oil such as SAE-30

Coolant Check coolant level daily. Service and maintain coolant system according

Air Cleaner Change air cleaner cartridge as required by air cleaner indicator (on engine

AC Generator AC generator bearings are sealed and require no periodic lubrication.

hours or one month of use. Use heavy duty oil such as SAE-30 (MIL-L-2104B). Engine lube oil capacity: 15 quarts.

(MIL-L-2104B). Lubricate only when starter is removed from engine.

to para. 7. Engine coolant capacity: 20 quarts.

control panel).

Lubrication and Maintenance Chart

Figure 3

e. Starter

The starting motor is lubricated at assembly and should be relubricated only when the starter is removed from the engine or when disassembled. Remove pipe plugs on outside of motor and apply a few drops of light engine oil to the oil wicks.

5. Air Cleaner Service

The air cleaner is a dry type with replaceable filter cartridges. A definite time schedule for changing the filter cartridge cannot be determined because of varying operating conditions. Change the filter cartridge when the red indicator “flag” reaches the top of the viewing chamber and locks in that position. Change the cartridge as follows:

a. Cartridge Removal (See Fig. 4)

(1)

Open canopy door.

(2)

Remove clamp assembly

(3)

Remove baffle assembly

(4)

Remove primary element

(5)

Inspect the interior of the cleaner housing

b. Cartridge Installation (See Fig. 4)

CAUTION

Do not clean or re-use cartridge.

(3)

from air cleaner

(7).

(4),

and replace with new element.

(1).

Make certain it is free from all foreign material.

(1)

Carefully install the new cartridge into the housing. Avoid bumping the cartridge tubes against the housing sealing flange. Seat the cartridge properly within the housing. Press all edges and corners of the cartridge firmly with fingers to effect a positive air seal against the sealing flange of the housing.

2-1 May 31/94 Revised Page 4

OM-499

CAUTION

(2)

Under no circumstances should the cartridge be pounded or struck in the center to effect a seal.

Lock the cartridge in place by installing the baffle assembly

(8)

assembly

in place. Tighten clamp

(3)

down in place.

(7)

and clamp assembly

(3)

with cup

6. Engine Fuel

a. Quality

The quality of fuel oil used in the diesel engine is a major factor in long engine life and performance. Fuel oil must be clean, completely distilled, stable, and non-corrosive. Only distillate fuel No. 1D is recommended for use both summer and winter.

CAUTION

b. Fuel Filter

Refer to Perkins Diesel Shop Manual in Chapter 6 for instructions on removal and replacement of fuel filter elements.

1. Body Assembly 5. Washer Gasket

2. “O” Ring 6. Wing Nut

3. Clamp Assembly 7. Baffle Assembly

4. Primary Element 8. Cup Assembly

Air Cleaner Cartridge Replacement

Figure 4

Consult the “ fuel oil selecting chart ” in the engine operator’s manual before substituting another grade of fuel.

May 31/94 Revised 2-1

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OM-499

7. Engine Cooling System

a. General

Cooling system device requires much more than maintaining the proper coolant level in the radiator. During warm seasons and in warm climates, plain water can be used as a coolant if the system is protected against rust by a rust inhibitor additive. During cold seasons and in cold climates, the system must, of course, be protected against freezing. At no time should the system be operated for any length of time on plain water, without a rust inhibitor or antifreeze. Draining, cleaning, and filling the cooling system are covered in Para. 7, E through H.

b. Radiator Cap

(1)

General A pressure valve is built into the radiator cap. It is designed to open at a pressure of

approximately seven pounds per square inch.

(2)

Removal To remove, turn the cap to the left

released, press down on the cap and continue to turn until the cap is free to be removed.

WARNING

Hot steam and fluids will severely burn! When removing cap from a very hot radiator, do not turn cap past safety stop until all pressure or steam has escaped. Use protective clothing. Allow engine to cool before adding coolant.

(counterclockwise)

to the safety stop. When all pressure is

(3)

Installation When installing the cap be sure it is turned clockwise as far as it will go so that the pressure

retaining valve will be functional.

c. Warm Weather Operation

During warm weather operation, if water is used in the cooling system instead of an antifreeze solution, keep the cooling system free of rust and sludge by adding a cooling system conditioner that is compatible with aluminum. Instructions for use of the conditioner are printed on each can.

CAUTION

Use only a corrosion inhibitor that is compatible with aluminum. Do not use inhibitors labeled as “acid neutralizer”.

d. Cold Weather Operation

(1)

General A permanent type,

(Ethylene Glycol)

antifreeze is recommended for use in the cooling system.

CAUTION

(a) Do not use “methanol” or alcohol as an antifreeze. (b) Do not use two different types of antifreeze.Mixed solutions (two types) make

it impossible to determine if the cooling system has adequate protection against freezing.

2-1 May 31/94 Revised Page 6

OM-499

(2)

Checking coolant solution Check the solution frequently to be sure the cooling system has sufficient protection against

freezing.

NOTE: When testing the solution, be sure the coolant is at operating temperature. (b) Follow manufacturer’s

instructions on tester.

(3)

Preparing the coolant solution The following table

antifreeze to 65% antifreeze. Percentages are based on permanent type antifreeze. Most antifreeze containers have a similar table printed on the label.

(Figure 5)

indicates the freezing points of solutions varying from 16%

(Ethylene Glycol)

FREEZING POINT

(FARENHEIT)

+ 20

+ 10

+ 0

- 20

- 30

- 40

- 50

- 60

- 70

PERCENTAGE OF ANTI-

FREEZE IN SOLUTION

16 % 25 % 33-1/3 % 40 % 45 % 50 % 54 % 58 % 62 % 65 %

Antifreeze Solution Table

Figure 5

(4)

Installing the antifreeze solution Before installing antifreeze in the system, make the following checks:

a. Check the system for signs of leaks. b. Inspect all hoses and tighten all hose clamps. Install new hoses if necessary. c. Drain and clean the system. Ref. Paras. 7,E and 7,F. d. Check the condition and tension of the fan and water pump belts and alternator belts.

Replace the belts if necessary.

e. Be sure radiator and engine drain valves are closed, and all connections are securely

tightened.

f. Installthe required amount of antifreeze: 20 quarts. Fill the system with coolant as outlined

under Para. 7, H.

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OM-499

e. Draining the Cooling System

Drain the cooling system immediately after stopping the engine, while most of the sediment is in suspension. Proceed as follows:

(1)

Remove radiator cap.

(2)

Open radiator drain valve Manual for exact locations of engine coolant drain valves.

NOTE: When draining the system for storage, remove all drain valves and remove drain plug.

(3)

Allow the system to drain completely.

NOTE: Be sure the drain valves do not plug-up during draining.

(4)

When the system is completely drained, close all drain valves except when draining for storage.

f. Cleaning the Cooling System

Drain and thoroughly flush the cooling system twice a year or more often if necessary. The appearance of rust in the radiator, or in the coolant is an indication that the inhibitor has become weakened and it is possible that some sludge has accumulated in the system. When this condition exists, proceed as follows:

(1)

Run the engine until it reaches normal operating temperature; then stop the engine and drain the cooling system

(at bottom of radiator)

(Ref. Para. 7, E).

and engine drain valves. See Perkins Shop

Fill the cooling system with clean coolant

(2)

Add a flushing compound, that is compatible with aluminum, to the cooling system in

(3)

accordance with the instructions furnished with the compound.

(4)

Start the engine and flush the system as directed by the instructions furnished with the compound.

(5)

After the system has been flushed and thoroughly cleaned of the compound, refill the clean coolant

g. Cleaning the Radiator Core

Blow out insects and dirt from the radiator core air passages, using air or water under pressure. Engine overheating is often caused by bent or clogged radiator fins. When straightening bent fins, be careful not to injure the tubes or to break the bond between the fins and tubes.

h. Filling the Cooling System

Add a cooling system corrosion inhibitor

(Ref. Para. 7, H).

(when the air temperatures expected are at freezing,+32 deg F or lower).

premixed if desired. See Fig. 3 for cooling system capacity.

(1)

Engine must be STOPPED. Close all drain valves except top water outlet valve. Leave this valve OPEN to allow air to escape.

(2)

Pour coolant into radiator slowly until system is filled to level of top drain valve. Close valve and continue to fill system until coolant reaches a level approximately 1 inch below the radiator filler neck.

NOTE: If antifreeze solution is not premixed, pour required antifreeze in first. Install corrosion inhibitor

according to directions on container.

(Ref. Para. 7, H).

(for warm weather operation)

or permanent antifreeze

Antifreeze may be

(3)

Start the engine and allow it to idle. Add coolant if trapped air escapes from the system and the coolant level falls.

(4)

Continue to check coolant level until the engine reaches operating temperature. Add coolant, if needed, to fill to the required level, 1 inch below filler neck. Install radiator cap.

2-1 May 31/94 Revised Page 8

OM-499

NOTE: It is good practice to attach a card, indicating the cooling system contents, and the date serviced to

the radiator filler neck.

8. Generator Maintenance

The 400-Hz generator requires no maintenance or service other than periodic cleaning. The unit is brushless, and bearings are permanently lubricated and sealed.

a. Cleaning

The generator may be cleaned by careful use of compressed air and/or a good, SAFE commercial cleaner. Steam cleaning of the generator is no longer recommended because the use of steam and harsh chemical compounds may result in damage to insulation and other generator components.

WARNING

Electric shock and fire can kill or injure! Be sure the unit is completely dry before operating. Do not use a flammable solvent.

b. Adjustment

The generator itself requires no adjustment. Adjustment procedures for generator controls will be covered in Section 2-3.

9. Drive Belts

Twin belts from the crankshaft pulley are used to drive the alternator and water pump. For proper engine operation these belts should be in good condition and at proper tension at all times.

a. Checking Belt Tension

Check belt tension every 200 hours of engine operation, or bi-weekly. Belts which are too tight are destructive to bearings of the alternator and water pump. A loose belt will slip and cause inefficient operation of the alternator and/or the water pump.

To check belt tension, press each belt firmly with the thumb at a point halfway between the alternator pulley and the crankshaft pulley. A properly adjusted belt should deflect about 3/8 inch.

b. Belt Adjustment

To adjust belt tension, loosen the alternator mounting bolts and change the position of the alternator. Upon obtaining the correct tension, re-tighten both alternator mounting bolts.

When new belts are fitted, it is necessary to run the engine for a short period to allow the new belts to settle into the grooves of the pulleys and thus show any initial stretching that is going to occur. Recheck belt tension after running the engine and adjust as necessary. Twin drive belts should be changed in pairs.

10. Trailer, Truck and Battery Maintenance

If the generator set comes with either the trailer or truck option, refer to Chapter 5 for the number of the manual which covers the particular option. The manual referred to will provide the appropriate maintenance procedure. Both manuals cover battery maintenance, as, when either option is used, the batteries are installed within it.

11. Service Helps

a. Wiring

All small wire leads are routed through plastic flexible conduit which protects them and makes a neat easily removable and replaceable wiring harness arrangement. This wiring method allows the replacement of a single wire lead with a minimum of difficulty. All wires are color coded.

May 31/94 Revised 2-1

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OM-499

b. Control Box Trays

Control box trays may be removed easily and moved to a work bench for service or replacement of parts.

(1)

Tray removal

a. Loosen screw-lock fastener (2, Fig. 6) b. Slide tray outward and disconnect Amphenol connector (3). c. Support tray with hands at each side of tray near latches (1).Unlock latches (1) by pressing

(2)

Tray installation

a. Use both hands to support tray as in removal above. b. Align rails (4) with tracks (5) and slide tray into box. Latches will lock automatically.

down with thumbs, then slide tray out of box.

1. Latch

2. Fastener

3. Connector

4. Rail

5. Track

Tray Removal

c. Connect Amphenol connector (3).

c. Generator Exciter

Provisions have been made to allow removal of the generator exciter without disturbing or removing the complete generator.

(1)

Preparation for exciter removal.

(Typical)

Figure 6

a. Remove main frame rear cross member by removing four attaching cap screws (See Fig. 7).

(2)

Exciter removal Refer to TM-360 in Chapter 6 for exciter instructions.

2-1 May 31/94 Revised Page 10

Removable Rear Frame Cross-Member

Figure 7

OM-499

(3)

Exciter installation

(a)

Install exciter in accordance with TM-360.

(b)

NOTE: It may be necessary to use a large “C” clamp or other arrangement to position frame side rails and

align rear frame member mounting holes.

d. Engine Control Panel

The engine control panel is designed and mounted in such a manner that it may be released from its mounted position and tilted outward for access to components mounted on the back side

Fig. 8).

panel forward. Do not disconnect the wires.

(1)

Tilt out engine control panel

Reinstall rear frame member and tighten screws securely.

(see

On dual output units it will be necessary to dismount the No. 2 output control to tilt the

a. Remove clamp screw which supports wire conduit above output terminal panel. b. Remove four cap screws which attach engine control panel to frame superstructure. c. Maneuver panel to tilt it inward at the bottom and outward at the top.

(2)

Reinstall engine control panel

a. Maneuver panel into position and align mounting holes. Install mounting screws and secure. b. Secure wire conduit in its original position with clamp and screw.

May 31/94 Revised 2-1

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OM-499

Engine Control Panel in Tilt-out Position

Figure 8

2-1 May 31/94 Revised Page 12

Section 2. Inspection / Check

1. General

This section describes inspections and checks to be performed in conjunction with Inspection/Check Schedule, Figure 1.

2. 2. Engine

a. Fuel (See Fig. 1 for time schedules)

(1)

Check fuel quantity DAILY.

(2)

Drain fuel filters and change fuel filter elements in accordance with instructions in Perkins Shop Manual.

(3)

Open fuel tank drain every 500 hours to drain off water and sediment.

b. Lubrication

(1)

Check crankcase oil level DAILY.

(2)

Lubricate in accordance with Lubrication Chart

(Ref. 2-1; Fig. 3).

OM-499

c. C. Coolant

(1)

Check coolant level DAILY.

(2)

Inspect for signs of rust and corrosion. Change coolant if rust and sediment are present. See 2-1; Para. 7, E, F, and H.

(3)

Inspect hoses for cracks and deterioration. Inspect clamps for tightness.

d. V-Belts

(1)

Inspect V-belts for proper tension and adjust if necessary after each 200 hours of operation.

(See 2-1; Para. 7, A, B, and C.)

e. Exhaust System

WARNING

(1)

Visually inspect muffler and exhaust pipes for signs of approaching failure.

(2)

Listen for any gasket or joint leaks.

(3)

Replace any defective parts at once.

Exhaust fumes or fire can kill or injure! Immediately repair defective exhaust systems.

May 31/94 Revised 2-2

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OM-499

HOURLY INTERVAL

CALENDAR INTERVAL

ENGINE

Check fuel quantity X Check crankcase oil level X Check coolant level X Check engine oil filter element X Change engine oil X Replace air cleaner cartridge X Inspect cooling system hoses,

tubes, fittings and clamps Check V-belt tension X Drain/refill cooling system * * Change fuel filter elements X Lubricate * Check exhaust system X Open fuel tank drain X

ELECTRICAL

Check all lights X Clean battery terminals X Check wiring X Check connections X

400 Hz GENERATING & CONTROL SYSTEM

Check output cable & connector X Check voltmeter X Check ammeter X Check frequency meter X Check all lights X Check protective relays X Check safety switches X Inspect all wiring & connections * * Clean & inspect generally * *

Required

Daily

8 Hrs

Bi-Weekly

100 Hrs

Monthly

200 Hrs

Bi-Monthly

400 Hrs

* See Lubrication Chart * * Twice Annually

Inspection / Check / Maintenance Schedule

2-2 May 31/94 Revised Page 2

Figure 1

3. Electrical System (12-V DC)

a. Lights

Check all lights for proper operation DAILY. Replace any defective lamps discovered. Figure 2 lists ALL lamps, their location, and part numbers.

b. Fuses

Check and replace fuses as required. See Figure 3 for fuse sizes and locations. Figure 3 includes all fuses used in both the engine and generator electrical systems.

(bulbs)

OM-499

as soon as

LIGHT

IDENTIFICAION

Instrument Panel Lights

Engine ON Indicating Light

Contactor CLOSED Indicating Light

Fault Indicating Lights Protective Relay Tray Lamp Industry Trade Clearance Lights Canopy Lamp Industry Trade

c. Wiring and Connections

(1)

Inspect all cables and leads for broken, worn, and damaged insulation.

(2)

Check electrical connections for looseness.

NOTE: A darkened terminal generally indicates a loose connection.

Control Box Lamp Industry Trade Engine Control Panel Lamp Industry Trade Engine Control Panel Lamp Industry Trade

LAMP

LOCATION

Lamp Identification Chart

Figure 2

MANUFACTURER NUMBER

Number Number Number Number Number

LAMP

63 1815 1815 1815 57

4. Electrical System (115-V AC)

The 400-Hz generator and controls are designed to be as maintenance free as possible. No lubrication is necessary and no periodic maintenance adjustments are required. However, some regular checks should be made to be sure all controls, instruments, etc., are working properly.

a. Monitoring Instruments

Observe operation of voltmeter, ammeter, and frequency meter each time the unit is started.

b. Indicating Lights

Check lamps protective relay tray may be tested by pressing test switch

c. Protective Modules

Check operation of all protective modules to make certain they will function if a fault should occur in the output circuit.

May 31/94 Revised 2-2

(bulbs)

(See 2-3; Para. 3, B.)

in all of the indicating lights at each start up. Fault indicating lights in the

(1-1; 8, Fig. 10)

Page 3

OM-499

ITEM PROTECTED LOCATION ILLUSTRATION SIZE & TYPE

Instrument Panel Lights and Engine Circuit

Protective relay system

Voltage regulator Voltage Regulator Sect. 1-1, Fig. 10, Load contactor circuit Protective Relay Tray Sect. 1-1, Fig. 8,

d. Wiring and Connections

WARNING

Engine Control Panel Sect. 1-1, Fig.9,

item 13

Protective Relay Tray Sect. 1-1, Fig. 8,

item 17 item 12 item 16

Fuse Identification Chart

Figure 3

Stop operations and stop engine before touching exposed conductors or terminals.

10A Type AGC 2A Type AGC 5A Type AGC 2A Type AGC

(1)

Check all cables, leads, and wiring for broken, worn, and damaged insulation.

(2)

Check all connections for tightness.

(3)

Check the output cable plug connector for damaged contactors in the end of the plug.

5. Trailer and Truck

If the generator set comes with either the trailer or truck option, refer to Chapter 5 for the number of the Hobart manual which covers the particular option. The manual referred to will provide the appropriate inspection procedure. Both manuals cover batteries, as, when either option is used, the batteries are installed within it.

2-2 May 31/94 Revised Page 4

Section 3. Adjustment / Test

1. General

Adjustment and test procedures are most applicable to testing and adjusting the generator set after a major repair, replacement of parts, or overhaul.

2. Test Panels (See Figure 1)

a. Generator Set Removed from Tractor

Tests and adjustments may be performed more conveniently while the generator set is out of the tow tractor. Prepare for test as follows:

(1)

Connect a source of D1 diesel fuel to the engine fuel system. Provide for fuel feed-back

Fig. 1).

OM-499

(Ref.

1. Fuel drain hose (to tractor tank)

2. Twelve-volt input terminal

3. Fuel input hose (from tractor tank)

4. Twelve-volt input cable (from tractor)

Fuel and Battery Connections

(Tractor-Mounted Unit)

Figure 1

(2)

Provide a source of 12-V DC battery power and connect to DC input terminal. Ground

NEGATIVE

Open access doors and remove access panels on right side of unit.

(3)

b. Generator Set in Tow Tractor

If the generator set is to be tested while mounted in the tow tractor, proceed as follows:

(Ref. Fig. 1)

(1)

Roll the unit out in accordance with instructions in Sect. 2-1, Para. 2, A.

(2)

Open access doors and remove right front engine access panel.

May 31/94 Revised 2-3

Page 1

OM-499

(3)

Remove power module and voltage regulator access panels

3. Generator Set Test

a. Pre-operational Test Procedures

(1)

Connect cables from the generator output terminals to a load bank. Use cables of the same size and length as those to be used in service. Be sure the generator output “N” cable is grounded.

(2)

Check engine oil level. Oil should be at FULL mark on gage rod.

(3)

Check radiator coolant level

(4)

Check tension of fan and generator V-belts.

(5)

If governor throttle linkage was disturbed, check all linkage to make certain engine speed may be controlled when the engine is started. See Figure 7

(6)

Inspect for oil, fuel, and coolant leaks.

(7)

If the setting of the voltage regulator rheostat position

(halfway between full clockwise position and full counterclockwise position).

(Ref. Section 2-1, Para. 7, H).

(37, Fig. 2)

(Ref. 1-1; 2, Fig. 1).

has been disturbed, set it at CENTER

Check engine circuit fuse

(8)

lights

(9)

Check fault indicating lights lamps are good.

(10)

Make a general inspection of all wiring and terminals. Inspect the equipment to be certain no damage will result from starting the engine.

(11)

At initial start-up after generator overhaul or repair, “flash” the exciter field by momentarily applying 12-V DC to the field windings as follows:

CAUTION

a. Flashing exciter field using test box.

(13)

operate, the fuse

Engine must not be running when flashing field if voltage regulator damage is to be prevented.

If a test box

(26, Fig. 2)

(26),

(9)

(see Sect. 1-3, Fig. 3)

by placing panel light switch

switch

by pressing test switch

(16),

and lamps are good.

(8).

If lights glow, fuse

is available, connect it to receptacle connector

(16)

in ON position. If panel

(11)

and indicating

(Sect. 1-3,

Fig. 4).

• (aa) Rotate the selector knob

• (bb) Use two jumper leads, each equipped with an alligator clip and a test prod, to connect

12-V DC power to test jacks terminal on starter solenoid to red test jack. Connect negative lead from starter ground terminal to black test jack.

• (cc) Momentarily pressing pushbutton switch field.

• (dd) Disconnect jumper leads.

(Sect. 1-3, Fig. 3, item 1)

(2 and 3)

on the test box. Connect positive jumper from input

(Sect. 1-3, Fig. 3, item 2)

to position 8.

will flash the exciter

2-3 May 31/94 Revised Page 2

b. Flashing exciter field without test box.

OM-499

Test Receptacle Connector

Terminals Identification

Figure 2

CAUTION

Flashing the field in a reverse direction could cause damage to voltage regulator diodes.

• (aa) Remove test receptacle cover prod on one end and an “alligator” clip on the other. Insert the test prod of one lead in terminal “D” of the test receptacle good GROUND. Insert the test prod of the second lead in terminal “F” of the test receptacle and momentarily touch the other end solenoid to flash the field.

• (bb) Disconnect leads and install receptacle cover

NOTE: If test leads with test prods are not available, insert short pieces of wire in proper test terminals to

make connections..

(12)

Check position of load contactor “on-off” switch (18).

a. Load contactor switch (20) must be in b. Engine-generator control switch (18) must be in

b. Operational Test Procedures

(1)

Start the engine in accordance with instructions in 1-3; Para. 2, A thru C.

(2)

Check operation of engine instruments: DC ammeter

(21),

oil pressure gage

(23),

and hourmeter

(1-3; Fig. 4).

(see Fig. 2),

(alligator clip)

(20, Fig. 1),

OFF

position.

(19).

Use two test leads equipped with a test

and connect the other end of the lead to a

to the “hot” terminal on the starter

and engine-generator control switch

IDLE

position.

(17, Fig. 2),

coolant temperature indicator

Check engine idle speed. Should be 825 to 875 RPM. Adjust, if necessary, in accordance with

(3)

instructions in Engine Operator’s Manual.

NOTE: A stroboscope is required for this check.

(4)

Again check for oil, fuel, and coolant leaks and correct any leaking condition.

(5)

Position switches and controls for automatic voltage regulation and power delivery as follows:

May 31/94 Revised 2-3

Page 3

OM-499

1. Frequency meter 12. Protective relay tray 22. Load contactor indicating light

2. Voltmeter 13. Instrument panel light 23. Oil pressure gage

3. Fastener 14. Generator control tray 24. Cold weather starting aid control

4. AC Ammeter 15. Fuel gage 25. Air cleaner indicator

5. Meter switch 16. Light switch 26. Engine circuit fuse (10-A)

6. Line switch 17. DC Ammeter 27. Engine protective circuit

7. Reset switch 18. Engine-generator indicating light

8. Light test switch control switch 28. Engine starter switch

9. Fault indicating lights 19. Hourmeter 29. Blocking diodes

10. Contactor circuit fuse (2-A) 20. Load contactor control switch 30. Permissive start switch

11. Protective system fuse (2-A) 21. Coolant temperature gage 31. Test receptacle connector

2-3 May 31/94 Revised Page 4

Operating Controls and Instruments

Figure 3 (Sheet 1 of 2)

OM-499

32. Manual voltage control rheostat 38. Cable length compensation

33. Automatic-manual voltage control rheostat switch 39. Cable size compensation

34. Test bank switch rheostat

35. Light test switch 40. Line-drop compensation on-off

36. Reset switch switch

37. Automatic voltage control 41. Fuse (5-A)

For units having a solid state regulator, refer to manual OM-2020 in Chapter 6.

May 31/94 Revised 2-3

Operating Controls and Instruments

Figure 3 (Sheet 2 of 2)

Page 5

OM-499

a. Place automatic-manual switch (33, Fig. 2) in b. Place test-bank switch (34) in

AIRCRAFT

AUTOMATIC

position.

c. Meter switch (5) may be in any position except pointing straight down. d. If the adjustment of the voltage regulator rheostat (37) has been disturbed, position the knob

to mid-range position.

(6)

Bring the engine up to governed speed and also energize the generator by holding the

(18)

engine-generator control switch and allow it to position in “center” RUN position.

If the engine “comes-up” to governed speed and a voltage value appears on the voltmeter the electric governor and excitationdeenergization relay circuits are functioning.

(7)

Observe frequency meter Hz. If not, adjust engine governed speed in accordance with Para. 4, E,

(8)

Observe voltmeter

(9)

Measure governor actuator input signal. See Par. 4, E,

(10)

Measure governor magnetic pickup signal. See Para. 4, E,

(11)

Check speed limiting governor Set engine speed-limiting governor to 2300 + / - 25 RPM. See Perkins Diesel Handbook in

Chapter 6 for instructions on how to set the governor.

(12)

Check adjustable voltage range in automatic operating mode.

(2).

(1).

Use rheostat

a. Observe voltmeter (2, Fig. 2) and turn rheostat (37)

in BUILD-UP-VOLTS position momentarily. Release switch

If engine speed is properly adjusted, frequency will be exactly 400

(37)

to adjust voltage to 115 V AC.

(3) (d).

See Fig. 12.

(4), (a).

(4), (b).

CLOCKWISE

to full clockwise position.

Maximum voltage should be at least 134 V AC, or higher.

(2),

NOTE: If voltage should decrease when the knob is turned clockwise, it indicates that internal wiring of the

voltage regulator is incorrect. Replace the complete regulator tray assembly.

b. Observe voltmeter and turn rheostat knob to full

COUNTERCLOCKWISE

position.

Minimum voltage should be 108 V AC, or lower.

Observe voltmeter and adjust rheostat to obtain 115-V AC voltmeter reading.

(13) (14)

Check adjustable voltage range in manual operating mode.

a. Open the generator control tray (14, Fig. 2) and place the automatic-manual switch (33) in

MANUAL

b. Observe voltmeter (2) and turn manual control rheostat (32)

position.

CLOCKWISE

to full clockwise

position. Maximum voltage should be at least 160 V AC.

c. Observe voltmeter and turn rheostat (32) to full

COUNTERCLOCKWISE

position. Minimum

voltage should be 95 V AC or less.

d. Adjust voltage to 115 V AC, then return the automatic-manual switch to

AUTOMATIC

position.

Position load bank switches, etc., to apply a light load to the generator.

(15) (16)

Place the load contactor “on-off” switch Hold in this position momentarily. Hold in this position momentarily. The indicating light should glow GREEN and an amperage value should appear on the AC ammeter

(17)

Release the switch should open immediately, and the generator “on” indicating light should go OFF. This is because the plug interlock relay source of 28 V DC. It indicates that the plug interlock contacts are OPEN as they should be when the interlock coil is not receiving 28-V DC power.

(2)

and allow it to return to the center ON position. The load contactor

(Ref. 1-1; 1, Fig. 8)

(20, Fig. 2)

in the top, spring loaded, CLOSE position.

(22)

(4).

is not receiving power from an outside

2-3 May 31/94 Revised Page 6

(18)

Open the protective relay tray and place the test bank switch position.

(19)

Again place the load contactor switch GREEN and remain ON when the switch is released and allowed to return to the center ON position. This indicates that the test bank switch relay.

(20)

Return the test bank switch to AIRCRAFT position. The load contactor should open at once and the green indicating light

(21)

Connect a source of 24-V DC power “N” and “F” terminal N and PLUS to terminal E or F.

(22)

With test-bank switch in AIRCRAFT position, hold the contactor operating switch CLOSE position momentarily. The generator “on” indicating light remain on when the switch is released and allowed to return to the center ON position. This indicates that the load contactor is closed and the plug interlock relay is functioning properly.

(23)

Apply 1/3 to 1/2 load at the load bank and allow the unit to run for 15 to 30 minutes. Observe operation of all monitoring instruments.

(24)

Increase load bank resistance to apply a full load.

(25)

Check operation of the governor by observing the frequency meter switched from no-load to full-load and vice versa. Use the contactor control switch and remove load several times. Frequency drop should be no more than 1 Hz. Adjust governor if necessary

(or “E”)

(see Para. 4, E, (3)).

(22)

should go off.

at the output terminal panel. Connection polarity should be: MINUS to

(20)

in the top, CLOSE position. Light

(34)

is functioning to by-pass the plug interlock

(two twelve-volt batteries connected in

(34, Fig. 2)

(22)

should glow GREEN and

(1, Fig. 2)

in TEST BANK

(22)

should glow

series) to terminals

(20)

when generator is

(20)

OM-499

in top,

to apply

(26)

Follow instructions in Para. 4, B, potentiometers potentiometer potentiometer (mounted below knobs).

(27)

Check voltage regulator, at intervals, from no-load to full load, and on up to 125% load. Observe and note voltage at various loads. Voltages should vary no more than plus or minus 1% from 115 V.

(28)

Check accuracy of voltmeter.

(Ref. Figure 2, items (38) and (39)). (39) (38)

to size to length

(2/0, 4/0, etc.)

(2) (b)

to set voltage regulator linedrop compensation

of cable being used. Set knob pointer on cable length

(20 feet, 40 feet, etc.)

Set knob pointer on cable size

of cable being used. See instruction plate

a. Open generator control tray (14, Fig. 2). b. Connect a master voltmeter of known accuracy to terminals of the voltmeter (2). c. Compare unit voltmeter reading with master meter. Error must not exceed 2% of full scale.

(29)

Check accuracy of AC ammeter.

a. Connect a master ammeter of known accuracy to the AC ammeter (4) terminals. b. Compare unit ammeter reading with master meter under various loads. Error must not

exceed 4% of full scale.

(30)

Check operation of meter selector switch position.

(31)

Check operation of the line switch the switch is in LINE-TO-NEUTRAL position. A voltage of approximately 200 V AC should be indicated when the switch is placed in LINE-TO-LINE position.

(6).

(5).

A voltage value should be shown in each switch

A normal voltage of 115 V AC should be indicated when

(32)

Check accuracy of frequency meter.

May 31/94 Revised 2-3

Page 7

OM-499

a. Connect a master frequency meter of known accuracy to the frequency meter (1) terminals. b. Compare meter readings. Error must not exceed 1% of full scale.

(33)

Operate the unit not less than 10 minutes under full load. The overload device

11)

MUST NOT trip.

(34)

Operate at 125% rated load for 5 minutes immediately following the fullload run. The overload device MUST trip within 5 minutes and the overload indicating light indicate an overload condition.

(35)

Reduce load to normal. Turn off indicating light by pressing reset switch

(36)

Check engine oil pressure at governed speed PSI when the engine is hot. Check engine coolant temperature. Gage should indicate in the range of 180 degrees to 190 degrees depending upon ambient temperature.

(37)

Check operation of fuse interlock remove protective relay circuit fuse immediately. This indicates that the fuse interlock relay is functioning properly. Replace fuse and apply load.

NOTE: Make all protective relay tests with the unit operating under load.

(38)

Check operation of overvoltage relay and indicating light.

(Ref. 1-1; 2, Fig. 8).

(Ref. 11, Fig. 2).

a. With the unit running at normal load, adjust the voltage regulator rheostat (37, Fig. 2) to

increase voltage (turn clockwise) until the the over-voltage sensing relay actuates the protective monitor to open the load contactor and turn on the overvoltage indicating light. The overvoltage sensing relay should trip when voltage reaches 130 V to 134 V.

(2000 RPM).

With unit operating normally under load,

The load contactor should open

(Ref. 1-1; 7, Fig.

(9, Fig. 2)

must come ON to

(7, Fig. 2).

Gage should indicate at least 38

b. Return unit to normal operating conditions by adjusting voltage regulator rheostat and

pressing reset switch (7).

(39)

Check operation of undervoltage sensing relay, indicating light, and time delay. Before starting this check, let us understand the sequence of events which should happen when voltage is reduced to 103 V or lower. At some value between 103 V and 93 V, the undervoltage sensing relay

(Ref. 1-1; 5, Fig. 8)

seconds after the time delay circuit is activated, should function to open the protective monitor relay which, in turn, will open the load contactor to stop power delivery. As a result of the action, the undervoltage indicating light turned ON. A stopwatch or sweep-second-hand watch is required for this check. Proceed as follows:

should function to activate the undervoltage time delay circuit. Five

(if the undervoltage condition continues)

a. With unit running at normal load, use the voltage regulator rheostat (37, Fig. 2) to reduce

voltage to 104V. The load contactor should

NOT

open after a 5-second delay.

b. Reduce voltage in steps of 1 V, with a delay of at least 5 seconds between steps. Restart

stopwatch or note position of sweep-secondhand each time voltage is reduced. At some voltage value between 103 V and 93 V, and 4 to 12 seconds after a new voltage setting is made, the load contactor should be opened and the undervoltage indicating light should be turned on by the step-by-step action of the undervoltage sensing relay, time delay circuit, and protective monitor relay.

NOTE: 1. The 4 to 12 second time delay is generally set at 5 seconds.

2. It may be necessary to switch to MANUAL control to obtain these low voltages.

c. If the load contactor is not opened at 103 V to 93 V, it will be necessary to refer to the

Trouble Shooting Chart, Section 3-1, to determine which component of the undervoltage protective circuit is defective.

(9)

should be

d. If the undervoltage circuit performs satisfactorily, return the unit to normal operation by

adjusting the voltage to 115 V, pressing the reset switch, and closing the load contactor.

2-3 May 31/94 Revised Page 8

(40)

Check underfrequency sensing relay, protective monitor, and indicating light. At some frequency value (Hz, cycles-per-second) from 385 Hz down to 375 Hz, the underfrequency sensing relay should function to signal the underfrequency circuit in the protective monitor module to OPEN the load contactor holding circuit, thus OPENING the load contactor. To check the underfrequency protective components, proceed as follows:

a. While the unit is operating normally under load, reduce generator output frequency by

reducing engine speed. Use the governed speed setting potentiometer (Ref. Fig. 9). Turn adjusting screw

COUNTERCLOCKWISE

gradually to reduce engine speed until frequency meter indicates 386 Hz. Underfrequency protective relay should not function to open the load contactor at this frequency. Reduce frequency in steps of 1 Hz.

b. If the protective system functions to open the load contactor and turn on the underfrequency

light after some frequency between 385 Hz and 37 Hz is reached, all components of the system are functioning properly. If the load contactor is not opened within the above frequency range, refer to Trouble Shooting Chart to determine which component is defective.

c. Return unit to normal operating condition.

(41)

Check overfrequency sensing relay, protective monitor, and indicating light. This protective circuit operates in exactly the same manner as the underfrequency circuit except its operating range is from 415 Hz to 425 Hz. Its purpose also is to open the load contactor and turn on an indicating light.

a. Check procedures are the same for overfrequency as for underfrequency (above) except

that engine speed is

INCREASED

to create a condition of overfrequency.

OM-499

b. If the overfrequency system functions to open the load contactor and turn on the

overfrequency light after some frequency between 415 Hz and 425 Hz is reached, all components of the system are functioning properly. If the load contactor is not opened within the above frequency range, refer to Trouble Shooting Chart to determine which component is defective.

(42)

If the generator is operating under load at this point, place the contactor control switch

in OFF position to open load contactor and disconnect load. There will be no further need for

the load bank in the following checks.

(43)

With the engine running at normal governed speed, check the entire unit for vibration and for any parts which may have become loosened during the above checks. Tighten any loose attaching hardware as required.

WARNING

Electric shock, moving parts, and noise can kill or injure! If a metal sounding rod is used to detect bearing noises, exercise extreme care to avoid injury.

(44)

Check 400-Hz generator bearings. Use a stethoscope or metal sounding rod to listen for unusual noises. If using a metal rod, place one end on the generator housing and hold the other end near the ear. Hold the rod with three fingers and use the index finger and thumb to form a “sounding chamber” between the rod and the ear. Do NOT allow the rod to touch the ear. Listen for “grinding” or pounding sounds which would indicate a defective bearing. An engine noise may be “telegraphed” to the generator and misinterpreted as a generator noise. Send the unit to overhaul if in doubt of bearing serviceability.

4. Generator Set Adjustment

(20, Fig.

a. Generator Adjustment

The 400-Hz generator is a brushless type requiring no adjustments of any kind.

b. Generator Control Adjustments

The following items may require adjustment at some time during the life of the equipment.

May 31/94 Revised 2-3

Page 9

OM-499

(1)

Adjust manual voltage control, variable resistor. The adjustment of this resistor

voltage obtainable when using the manual control rheostat for voltage control. To adjust maximum voltage potential, proceed as follows:

(Ref. 1-1; 1, Fig. 7)

determines the maximum generator output

a. Loosen slider-band clamping screw. b. Move the slider-band toward the single wire end of the resistor to increase voltage potential.

Move the band toward the double wire end (two wires connected) to decrease voltage potential.

c. Tighten slider-band clamping screw.

(2)

Adjust 400-Hz voltage regulator. NOTE:

The following adjustments are for the magnetic amplifier type voltage regulator, identified by Hobart Part Number 430491C, illustrated herein, and covered by manual number TM-759 in Chapter 6. For units having the newer solid state voltage regulator, refer to manual number OM-2020 in Chapter 6.

When a voltage regulator is first put into service, or when output are changed, the regulator may require up to five separate adjustments. The five adjustments are for generator output voltage value, damping gain, damping rate, line drop compensation gain, and line drop compensation rate. See Figure 4 for identification of components used for regulator adjustment.

(generator-to-aircraft)

a. Adjust generator output voltage.

This is a relatively easy adjustment to make. With the generator running at a rated speed (2000 RPM) and rated cycles-per-second CLOCKWISE to INCREASE voltage and COUNTERCLOCKWISE to DECREASE voltage. Observe the AC voltmeter and adjust output voltage to 115 V AC.

(400 Hz),

rotate the rheostat knob

(1)

cables

b. Adjust cable length and cable size compensation rheostats.

These two adjustment should be made together. Switch follows:

• (aa) Adjust the rheostat Various cable lengths are indicated on a plate mounted behind the rheostat knob.

• (bb) Adjust rheostat also indicated on a plate behind the rheostat knob.

• (cc) With generator running 115 V AC. If not, adjust in accordance with Para. 4, B,

• (dd) Apply a full load to the generator. Observe AC voltmeter. If the voltage observed varies more than 1% obtain a voltage of 115 V AC, or as close to this value as possible. Turn knobs CLOCKWISE to INCREASE voltage and COUNTERCLOCKWISE to DECREASE. Turn each knob a small amount at a time to determine which rheostat is having the most effect on output voltage and requires adjustment.

(2)

to point to the length, in feet, of output cable being used.

(3)

to point to the size of cable being used. Various cable sizes are

(no load),

(plus or minus)

check output voltage value, which should be exactly

from 115 V AC, adjust rheostats

(4, Fig. 4)

(2), (a)

above.

must be ON. Proceed as

(2)

and

(3)

slightly to

c. Adjust “damp” and “rate” adjusting potentiometers (see Figure 5).

Damping adjustments are very delicate and should not be attempted unless the generator output average phase value varies more than 1 volt, or output voltage is unstable. “Damp” and “rate” adjustments must be made in conjunction with each other because the adjustment of one may affect the other. For example, improving the response by adjusting the “damp” potentiometer as follows:

• (aa) If “damp” and “rate” adjustments have been disturbed (changed from factory or if the regulator has been repaired, loosen locking nuts and set both potentiometers to mid-position

(1)

may affect the stability as adjusted by the “rate” potentiometer

(2).

setting),

(halfway between full CLOCKWISE and full COUNTERCLOCKWISE).

Adjust

2-3 May 31/94 Revised Page 10

OM-499

• (bb) Connect the generator output to a balanced, three-phase load of 30 kilowatts.

• (cc) With generator running at 115 V AC no load, operate the contactor “on-off” switch

Fig. 2).

adjust “damp” and “rate”.

• (dd) Turn the “damp” COUNTERCLOCKWISE to improve STABILITY. Generally the best adjustment is approximately 3/4 of full CLOCKWISE travel.

• (ee) Turn the “rate” the screw slowly CLOCKWISE until the voltage output abruptly becomes STEADY. Continue turning the screw CLOCKWISE 5 deg to 10 deg past this point for best “rate” adjustment.

• (ff) Tighten adjusting screw locknuts after adjustment is completed.

If the average phase voltage changed more than 1. volt, or if output is unsteady,

(1, Fig. 5)

(2)

adjusting screw to near full COUNTERCLOCKWISE position. Turn

adjusting screw CLOCKWISE to improve response. Turn

(20,

1. Voltage adjusting rheostat 5. Fuse (5 Amp)

2. Cable length compensation rheostat 6. Fuseholder

3. Cable size compensation rheostat 7. Damp (gain) adjusting potentiometer

4. On-off switch, line-drop compensation 8. Rate adjusting potentiometer

May 31/94 Revised 2-3

Voltage Regulator Adjustments

Figure 4

Page 11

OM-499

Voltage regulator Damping Adjustments

Figure 5

c. Basic Engine Adjustments

Adjustment procedures applicable to the diesel engine are included in the Perkins Diesel Handbook which accompanies this Hobart manual. Specific information for this particular engine is listed in Figure 6.

d. Engine Accessories Adjustment

(1)

Generator and fan belt adjustment Refer to 2-1; Para. 8 for fan belt adjustment instructions.

NOTE: Replace fan belts as a matched set.

e. Electric Governor System Adjustment

(1)

General The complete Hobart electric governor kit, identified as Hobart Part No. 282671, consists of

Barber- Colman governor parts with brackets and hardware added by Hobart Brothers to install the governor system on generator sets in this series. The Barber-Colman governor system consists of in the flywheel housing, which senses engine speed off the flywheel teeth.

2-3 May 31/94 Revised Page 12

(1)

an electric controller,

(2)

an actuator, and

(3)

a magnetic-pick-up that is installed

Manufacturer Perkins Engines, Inc. Model 6-3544 Type In-line, 6-cylinder, 4-cycle diesel Displacement 354 cubic inches (5.8 liters) Compression ratio 16:1 Firing order 1-5-3-6-2-4 Number of main bearings 7 Horsepower at 2000 RPM 83 Governed speed 2000 RPM + / - 4.5% Idle speed 850 + / - 25 RPM Electrical system 12 volt Oil capacity 15 quarts (14 liters) Coolant capacity (approx.) 20 quarts (19 liters) Fuel Diesel oil conforming to ASTM

Specification D.975-66T, Nos. 1-D and 2-D

Lubricating oil MIL-L-2014B

OM-499

Engine Specifications

Figure 6

Two governor system components, namely the magnetic pick-up and the controller, have critical adjustments which can affect engine performance and generator output. Actuator-to-engine speed control lever adjustment can also affect engine performance.

When the complete system is to be checked and/or adjusted, a definite sequence of procedures should be followed:

First - Check or adjust actuator linkage. Second - Check or adjust magnetic pick-up. Third - Check or adjust governor controller settings.

(2)

Actuator Linkage Adjustment The proper adjustment of the mechanical linkage between the governor actuator and engine

speed control lever is important to the satisfactory operation of the complete system. Two definite rules must be followed in making the adjustment:

Adjust linkage to use the FULL TRAVEL of the actuator output shaft. Linkage must move engine speed control lever from FULL IDLE to RATED SPEED

position, or VERY CLOSE to FULL SPEED position to allow the engine to pull maximum load.

With the engine stopped, refer to Figure 7 and proceed with linkage adjustments as follows:

a. At the engine speed control lever (6), loosen the jam nut (5) that fastens the ball joint (7) to

the threaded rod, and remove the ball joint from the engine speed control lever.

b. Rotate the ball joint - outward or inward - on the threaded rod (8), as necessary, to acheive a

distance of approximately 6 inches (153 mm) from center to center on the swiveling portions of the two ball joints (4 and 7).

May 31/94 Revised 2-3

Page 13

OM-499

c. While holding the removed ball joint in its mounting hole in the engine speed control lever,

compare the

TRAVEL

of the

ACTUATOR SHAFT

(2) with the travel of the engine speed

control lever (6).

d. At

FULL IDLE

position, the actuator shaft should be pulled

ALL THE WAY DOWNWARD.

e. For

RATED SPEED

, the actuator shaft should come out far enough to force the engine

speed control lever to use

ALL OF ITS TRAVEL

as it moves upward. f. Re-attach the ball joint to the engine speed control lever with the lockwasher and nut. g. Tighten the two jam nuts on the threaded rod firmly against their respective ball joints.

h. Check governor linkage for freedom of travel. Move the rod assembly manually to see that

there isn’t any binding or lost motion in linkage. Make corrections if and as required.

1. Actuator

2. Actuator shaft

3. Clevis, actuator shaft

4. Ball joint, actuator

5. Jam nuts

6. Engine speed control lever

7. Ball joint, engine speed control

8. Rod

9. Mounting brackets, actuator

2-3 May 31/94 Revised Page 14

Governor Actuator

Linkage

Figure 7

OM-499

i. Make a preliminary setting of engine idle speed by adjusting the idle speed set screw, which

is located on the engine speed control lever. See that this screw is turned to 5 turns, to force the engine speed control lever downward slightly from the full upward position.

INWARD

about 3

(3)

CAUTION

j. Start the engine, and set the idle speed to

850 RPM + / - 25 RPM

. Operate engine at idle speed until it is warmed to operating temperature. Then re-adjust idle speed set screw, if necessary, to obtain the original

Magnetic Pick-up Inspection / Adjustment Figure 8 shows how the magnetic pick-up is mounted. This area of the generator set can be

seen by opening the door on the front left side of the generator set and viewing the side of the flywheel housing. The strength of the magnetic pick-up signal to the controller can be weakened if the tip of the pick-up is too far from the flywheel ring gear or if it becomes damaged.. If the pick-up is removed for any reason, or if the signal is weak, adjust the magnetic pick-up as follows:

850 RPM + / - 25 RPM

a. Loosen the jam nut on the pick-up, by turning it toward the wire end of the pick-up. b. Remove the magnetic pick-up and inspect for damage, replace if necessary. Clean the tip

and reinstall.

The pickup tip must be directly over a tooth and not between teeth when adjustment is made.

c. Continue turning the pick-up d. Back the magnetic pick-up out 1/4 to 3/4 of a turn

CLOCKWISE

until it bottoms out (it has hit the ring gear teeth).

COUNTERCLOCKWISE

. This creates a

gap between the magnetic pick-up and the ring gear.

e. While referring to the appropriate connection diagram, disconnect magnetic pick-up wires at

the terminal strip to which the wires are connected.

f. Start the engine and run at idle speed.

1. Magnetic pick-up

2. Adjustment nut

Magnetic Pick-up Adjustment

(Typical)

Figure 8

May 31/94 Revised 2-3

Page 15

OM-499

g. Connect the pick-up wires to a voltmeter. The signal should read between 4 and 8 VAC. h. If the signal is weaker than 4-V AC, check connections. If necessary, check magnetic

pick-up continuity or idle speed setting on the fuel pump.

i. Tighten the jam nut when the pick-up is properly adjusted. j. Reconnect the wires to the terminal strip.

(4)

Governor Controller Adjustment The governor controller is located on the large panel to the left of the generator control box, as

viewed from the left side of the generator set. Before making an adjustment to the controller, make sure the linkage between the actuator and the engine speed control is free and properly adjusted. There must be no lost motion or “play” in the linkage. Be sure the magnetic pick-up is producing a strong, normal output.

The controller has two control potentiometers: the SPEED control potentiometer and the GAIN potentiometer. Make the controller settings as follows:

NOTE: A very small screwdriver is required for this adjustment.

a. With the engine warmed to operating temperature, use operating mode switch to bring the

generator set from idle to rated speed.

b. Adjust the

speed (2000 RPM). To potentiometer the potentiometer

SPEED

potentiometer on the controller until the engine is operating at rated

CLOCKWISE.

COUNTERCLOCKWISE.

INCREASE

DECREASE

engine speed when making this setting, turn the

engine speed when making this setting, turn

c. If the governor oscillates, causing the governor-actuator linkage rod to move in an unstable

manner, adjust the subsequent instability is just barely eliminated. Then re-adjust the

GAIN

control on the governor controller until the oscillation and

SPEED

if necessary.

2-3 May 31/94 Revised Page 16

Governor Controller

Figure 9

OM-499

d. Upset the engine speed control lever by hand. If the lever oscillates in 3 to 5 diminishing

oscillations and stops, the setting is correct.

e. Apply a load to the generator set, then remove the load and observe the length of time

required for the engine speed to again stabilize. Engine speed should stabilize within 3 to 5 oscillations.

f. If engine speed does not stabilize at the above setting, continue making slight adjustments to

the

GAIN

control, and checking stability and engine speed between no-load and full-load,

until the engine speed stabilizes.

(5)

Re-checking Actuator Linkage Perform this check ONLY if the engine doesn’t come up to rated speed from idle speed, or

doesn’t maintain rated speed under load. If either of these conditions exist, check and adjust linkage as follows, with engine stopped.

a. Disconnect the ball joint from the actuator shaft clevis . b. Be sure the engine speed control lever is not slipping on its shaft. If it is slipping, position it

correctly and tighten it securely.

c. Place the engine speed control lever in

FULL IDLE

position and attempt to connect the ball joint at the hole in the lever from which it was removed (Step 1). If the holes don’t align correctly, loosen the ball joint nut and adjust the effective length of the rod assembly shorter or longer - and re-connect it to the actuator clevis.

d. Tighten the ball joint nuts securely and operate the generator set to check governor’s control

of idle speed, rated at no-load speed, and full-load speed.

e. Repeat this procedure until generator set operates at proper speeds, with and without load.

(6)

Checking the Actuator The actuator does not require any adjustments. An actuator malfunction, when it occurs, will

result in the actuator being totally inoperative, either due to the actuator coil being open or shorted to the actuator case. Resistance measurements will reveal either of these conditions.

5. Generator and Exciter Test

The generator fields may be tested with a “Kelvin” bridge. This is a double-bridge type instrument required for the very low resistances encountered in this test. It is understood that 0 resistance indicates a SHORT CIRCUITED condition. An infinite resistance reading indicates an OPEN

CIRCUITED condition. See Fig. 10 below for resistance values.

NOTE: The equipment should be COLD or at normal ambient temperature when tests are made.

a. Disconnect generator stator leads at the power module panel. b. Disconnect exciter leads from terminal board mounted on rear of engine control panel.

Positive lead is RED Negative lead is YELLOW-BLACK.

c. Check resistances and compare to values given in Fig. 10.

6. Diode Test

Test values for diodes are not given here because they could be misleading. Test values may vary even between diodes of the same part number, rating, and manufacturer. General instructions for testing diodes follows:

a. Disconnect diode lead(s). b. Use a good quality ohmmeter. An instrument which indicates 50 ohms at the center of the

scale is preferable.

NOTE: Make certain the battery is in good condition and the pointer is adjusted to zero when the test lead

points are shorted together. Set the scale selector to RX1.

May 31/94 Revised 2-3

Page 17

OM-499

TEST CONNECTION NOMINAL RESISTANCE IN OHMS GENERATOR STATOR

Phase A to N * 0.00827 Phase B to N * 0.00835 Phase C to N * 0.00840

EXCITER A-B, B-C, A-C 0.1

Field

(RED to YELLOW-BLACK)

7.23

ROTATING FIELD Measure resistance at revolving field rectifier

(CR2)

rectifier. (See Connection Diagram)

with exciter armature leads removed from

* The two leads of a phase must be connected when test is made.

Generator and Exciter Stator Test Values

c. Hold one ohmmeter lead point on the threaded end of the diode. Hold the other lead point

on the wire terminal end. Observe and note the indicated resistance. Now reverse the lead connections on the diode. Again observe and note the ohmmeter indicated resistance. Generally speaking, if an infinite or very high resistance was indicated with the leads connected one way and a low, readable resistance was indicated with the leads connected the opposite way, the diode may be considered good.

(70

F Ambient Temperature)

Figure 10

2.19

7. Additional Test for Dual Output Unit

Perform the tests outlined in para. 3. B illustrated in Figure 12.

(16)

through

(22)

substituting the controls and indicators

2-3 May 31/94 Revised Page 18

OM-499

TEST BOX POINTER POSITON

1 K-M Phase “A” input for reg. and

2 K-P Phase “B” input for reg.and

3 K-S Phase “C” input for reg. and

4 K-A Protective monitor fuse Battery voltage 12-VDC 5 K-B Fuse interlock relay Test bank sw. Closed &

6 H-S Protective monitor contacts Auto-mansw. in “AUTO

7 K-Z Pluginterlock relay Plug in aircraft 28-V DC 8 D-F Exciter input Unit in “GEN mode 8-12

9 V-X Regulator output** Unit in “GEN mode &

10 K-B Contactor operation Test bank sw. Closed &

11 K-E Overload contacts at less

12 K-R Contactor switch Test bank sw. closed &

13 K-N Battery voltage and engine

14 K-J Shut-down solenoid Engine running O-V DC 15 K-G Governor and EDR Unit in “GEN” mode 12-V DC

TEST POINTS CONNECTOR TERMINALS

TEST DESCRIPTION

trays

than 125% load

circuit fuse

CONDITION VOLTAGE

Unit in “GEN” mode 115-V AC

Unit in “GEN mode & auto-man sw. in ”AUTO"

contactor closed

position

auto-man sw.in ”AUTO"

contactor closed Test bank sw. Closed &

contactor closed

contactor sw. closed in “ON” position

All conditions 12-V DC

400 HZ 115-V AC

400HZ 115-V AC

400HZ

12-V DC

115-V AC

VDC 50-70 V

DC* 115-V AC

O-V DC

115-V AC

16 U-W Governor actuator Unit at idle speed O-V DC

Typical Test Values at Test Receptacle Connector or Test Box

May 31/94 Revised 2-3

Figure 12

Page 19

OM-499

2-3 May 31/94 Revised Page 20

No. 2 Output on Dual Output Units

Figure 13

OM-499

Chapter 3. Troubleshooting Procedures

Section 1. Troubleshooting

1. General

a. Troubleshooting is an orderly process of checking and eliminating possible causes of trouble until

the exact cause is located. When looking for the cause of a trouble in a circuit or system begin at the source of power or supply. Continue testing and checking the circuit, or system, step-by-step, in an orderly manner, until the cause of trouble is located.

b. The chapter provides information for diagnosing and correcting certain troubles which cause

unsatisfactory operation or failure of the equipment.

c. Minor troubles may be remedied by the operator, however, major repairs must be undertaken by

experienced mechanics and electricians only.

2. Troubleshooting

a. Description

The troubleshooting chart lists information under three headings as follows:

(1)

Trouble, Symptom, and Condition

(2)

Probable cause

(3)

Test, Check, and/or Remedy

b. Use of the Troubleshooting Chart

(1)

A troubleshooting chart is furnished to provide maintenance and repair personnel with a time-saving guide for locating trouble. To use the chart, proceed as follows:

Locate the symptom(s) of trouble in the “Trouble” column.

Check the probable causes of trouble in the “Probable Cause” column.

Test, check, repair, or correct the trouble as indicated in the “Remedy” column.

(2)

If the cause of a trouble is an uncommon one and cannot be located by use of the chart, start at the source of power or supply and check the affected circuit or system completely. Use schematic and connection diagrams supplied with this manual.

(3)

Electrical components mentioned in the troubleshooting chart are identified by a noun name and a corresponding symbol which allows the user to identify the item more easily on schematic diagrams.

(4)

It is assumed that wiring and connections in defective circuits have been thoroughly checked before condemning any other components.

NOTE: Reference symbols (S9, etc.), used in the Troubleshooting Chart, are identified on Schematic

and Connections Diagrams.

May 31/94 Revised 3-1

Page 1

OM-499

3. Equipment for Troubleshooting

A good quality multi-scale volt-ohmmeter is the only instrument required for troubleshooting. At least two “jumper” leads with “alligator” clips and test prods will be required. The 12-V, engine electrical system may be used as a 12-V DC power source.

If a test box, part number 388318A -2, is available tests may be made more quickly and accurately, however, the test receptacle connector may be used by inserting the test points of a volt-ohmmeter into proper terminals of the connector. Refer to Fig. 8.

4. Safety

WARNING

Electric shock and moving parts can kill! Exercise extreme care to avoid contact with high voltage parts or leads and moving parts when trouble shooting or operating the equipment. Remove jewelry such as rings and watch.

5. Parts Replacement

To lessen end item “down” time and to get a faulty machine back “on-the-line” as quickly as possible, the “black-box” concept of parts replacement is reflected in the troubleshooting chart. For example, if a component in the protective relay tray is defective, the quickest way to remedy the situation is to replace the complete tray assembly and send the old tray for repair.

Assemblies which lend themselves to this concept are:

• Generator control tray

• Protective relay tray

• Voltage regulator

• Overload module

• Protective monitor module

• Electric governor control “box”

• Governor actuator

• Over-undervoltage module

• Over-underfrequency module

The above items are in addition to normally replaced items such as fuel pump, injectors, relays, etc.

6. Test Values

Although test values are provided, where applicable, throughout the troubleshooting chart additional information and values are given here.

• Generator output at maximum voltage regulator rheostat setting 134 V or higher

• Generator output at minimum voltage regulator rheostat setting 108 V or lower

• Overload relay trips at any value above 125% load in 5 minutes or less.

• Overload relay trips at 130 to 134 V AC, resets at 125 V AC.

• Undervoltage relay trips at 93 to 102 V AC, resets at 110 V AC.

• Undervoltage time delay circuit functions in 4 to 12 seconds.

• Overfrequency relay trips at 415 to 425 Hz, resets at 410 Hz.

• Underfrequency relay trips at 375 to 385 Hz, resets at 385 Hz.

• Overload relay trips at 125% rated load in 5 minutes.

3-1 May 31/94 Revised Page 2

OM-499

See 2-3 Fig. 13 for typical test values at test receptacle and test box.

7. Check Connections and Leads

ALWAYS make a check of connections and leads to a component suspected of being faulty. With the exception of a few instances, we will assume that connections and wiring have always been checked first and that power has not been lost as a result of defective wiring or connections.

8. Electric Governor Trouble Shooting

The following facts concerning the operation of the electric governor may be helpful in understanding the system and in determining which unit in the system is faulty in case of troubles.

a. The system requires two sources of power to operate normally.

(1)

12-V DC input power (from engine electrical system)

(2)

AC input power (from magnetic pickup)

b. Assuming other conditions are normal, the actuator will go to, or remain in, IDLE position

under the following conditions.

(1)

No 12-V DC power to control box.

(2)

No voltage from control box to actuator.

(3)

No signal from magnetic pickup.

c. The actuator will “surge” under the following conditions:

(1)

“Stability” or “gain” adjustment set too “high”.

(2)

Throttle linkage binding.

9. Engine Trouble Shooting Procedures

a. General

The following engine troubleshooting procedures were taken from Perkins Diesel’s “Field Service Data Book”. Certain abnormal conditions which may interfere with satisfactory engine operation, together with methods of determining the cause of such conditions, are covered in the Trouble Shooting Chart.

The ability of the engine to start and operate properly depends primarily on two things:

(1)

The presence of an adequate supply of air, compressed to a sufficiently high compression pressure.

(2)

The injection of the proper amount of fuel at the right time. Lack of power, even running, excessive vibration, stalling, and hard starting may be caused by

low compression, faulty injection in one or more cylinders, faulty timing or valves, or lack of sufficient air. Refer to Perkins Diesel Handbook for troubleshooting and repair procedures.

10. Illustrations

Illustrations, Figures 1 through 8, are referred to throughout the Trouble Shooting Chart

May 31/94 Revised 3-1

Page 3

OM-499

1. Frequency meter 12. Protective relay tray 22. Load contactor indicating light

2. Voltmeter r 13. Instrument panel light 23. Oil pressure gage

3. Fastener 14. Generator control tray 24. Cold weather starting aid control

4. AC Ammeter 15. Fuel gage 25. Air cleaner indicator

5. Meter switch 16. Light switch 26. Engine circuit fuse (10-A)

6. Line switch 17. DC Ammeter 27. Engine protective circuit

7. Reset switch 18. Engine-generator indicating light

8. Light test switch control switch 28. Engine starter switch

9. Fault indicating lights 19. Hourmeter 29. Blocking diodes

10. Contactor circuit fuse (2-A) 20. Load contactor control switch 30. Permissive start switch

11. Protective system fuse (2-A) 21. Coolant temperature gage 31. Test receptacle connector

3-1 May 31/94 Revised Page 4

Operating Controls and Instruments

Figure 1 (Sheet 1 of 2)

OM-499

32. Manual voltage control rheostat 38. Cable length compensation

33. Automatic-manual voltage control rheostat switch 39. Cable size compensation

34. Test bank switch rheostat

35. Light test switch 40. Line-drop compensation on-off

36. Reset switch switch

37. Automatic voltage control 41. Fuse (5-A)

For units having a solid state regulator, refer to manual OM-2020 in Chapter 6.

May 31/94 Revised 3-1

Operating Controls and Instruments

Figure 1 (Sheet 2 of 2)

Page 5

OM-499

1. Manual control voltage potential adjusting resistor

2. Exciter field ballast resistors

Excitation Resistors

Figure 2

3-1 May 31/94 Revised Page 6

End view of Voltage

Regulator Amphenol

Connector

Figure 3

OM-499

Test Receptacle Connector

Terminals Identification

Figure 4

May 31/94 Revised 3-1

Page 7

OM-499

This page intentionally left blank.

3-1 May 31/94 Revised Page 8

Engine and Controls

Trouble, Symptom & Condition Test or Inspection Corrective Action

OM-499

1. Engine will not start. Starter

will NOT crank engine.

2. Engine will not start. Cranking speed low.

a. Batteries discharged or

loose battery or ground connection

b. Defective starter solenoid,

or starter.

c. Defective starter

d. Internal seizure

a. Low battery output or

faulty starter.

Check voltage across batteries. Voltage should be approximately

13.5-V DC. Check all battery terminals. Be sure 13.5-V DC is reaching solenoid input terminal.

Momentarily connect a large size starter cable between the hot side of the starter solenoid and the starter input terminal.If the starter cranks the engine, it indicates that the starter solenoid is defective. Replace it. If the starter did not operate, proceed to step D.

If starter did not operate in check C above, the starter is defective. Replace it.

If all engine starting components are good and the starter is unable to crank the engine, internal seizure is indicated. For repair procedure see Perkins Diesel workshop manual.

Check battery and starter. Recharge, repair, or replace.

3. Engine will not start. Cranking speed normal.

b. Loose starting circuit

connections or faulty cables.

c. Improper lubricating oil

viscosity.

a. No fuel.

b. Insufficient fuel in tank

Check all connections and cables. Tighten or replace as required.

Check oil. See Sect. 2-1, Para. 4, D, (3).

Before attempting to find the cause of “no fuel”, prime the fuel filters by removing pipe plug in the cover of each. Fill each filter with fuel oil. If the engine will not start after priming, mechanical pump trouble is indicated. If the engine starts and then stops after a short time, trouble between the fuel source and the suction side of the pump is indicated. Check and/or remedy as follows (see Fig. 7).

Fill tank.

May 31/94 Revised 3-1

Page 9

OM-499

Engine and Controls

Trouble, Symptom & Condition Test or Inspection Corrective Action

Engine will not start. Cranking speed normal. (Continued)

4. Engine is hard to start. Cranking speed normal.

c. Fuel shut-off valve closed Make certain that fuel shut-off

valve is open

d. Loose connections,

damaged hoses or fuel lines between tank and fuel pump

e. Plugged or defective fuel

filter

f. Faulty installation

g. Faulty fuel pump: relief

valve not seating, worn pump gears, or damaged pump drive.

h. Defect in injector racks or

linkage

a. Low ambient temperature,

pr limited fuel

Tighten all fittings and connections. Replace any damaged hoses or fuel links.

Do not overlook the possibility of restricted flow through the fuel filters. Also check gaskets for leaking or damaged condition.

Restriction fitting missing from return line.

Check fuel pump for an open relief valve, worn gears, or damaged pump drive. Replace if defective.

Refer to Perkins Diesel handbook. Make adjustments and/or repairs according to instructions therein.

Check causes and remedies under ENGINE, Trouble 3 above.

b. Low compression which

may be caused by any one of the following:

c. Sticking or burned exhaust

valves

d. Compression rings worn or

broken

e. Cylinder head gasket

leaking

f. Improper valve clearance

adjustment

Check compression in accordance with Para. 9, C and D.

Cylinder head must be removed and overhauled to correct this condition.

Check rings in accordance with instructions in Perkins Diesel handbook.

Check rgasket in accordance with instructions in Perkins Diesel handbook.

Check and adjust valve clearance in accordance with instructions in Perkins Diesel handbook.

3-1 May 31/94 Revised Page 10

Hobart 6824-1, 6824-2, 6824-3, 6824-4, 6824A-1 Operation And Maintenance Manual

Specifications and Main Features

Frequently Asked Questions

User Manual