Hobart 60CU24 Operation And Maintenance Manual With Illustrated Parts List

OM-2098C

040105 – Original
070308 – Revision 9

Operation and Maintenance Manual

with

Illustrated Parts List

for

60CU24

60 kVA, 3 Phase, 115/200 Volt,

400 Hz. Generator Set

Series 500060C

ITW GSE Group

Hobart Ground Power

Troy, Ohio 45373

U.S.A.

Data Sheet 165

Warranty

HOBART GROUND POWER

TROY, OHIO 45373

1. Hobart Brothers Company (hereinafter called HOBART) warrants that each new and unused Hobart Ground Power

Equipment, (hereinafter called the PRODUCT) is of good workmanship and is free from mechanical defects,
provided that (1) the PRODUCT is installed and operated in accordance with the printed instructions of HOBART,
(2) the PRODUCT is used under the normal operating conditions for which it is designed, (3) the PRODUCT is not
subjected to misuse, negligence or accident, and (4) the PRODUCT receives proper care, lubrication, protection,
and maintenance under the supervision of trained personnel.

2. This warranty expires 15 months after shipment by HOBART to the first user, or 12 months after installation,

whichever first occurs.

3. This warranty does not apply to: primary and secondary switch contacts, cable connectors, carbon brushes, fuses,

bulbs, and filters unless found to be defective prior to use.

4. Hobart DOES NOT WARRANT THE FOLLOWING COMPONENTS: Engines, engine components; such as:

starters, alternators, regulators, governors, etc., and cable retrieving devices. Many of the foregoing components
are warranted directly by the manufacturer to the first user and serviced by a worldwide network of distributors and
others authorized to handle claims for component manufacturers. A first user’s claim should be presented directly
to such an authorized component service outlet. In the event any component manufacturer has warranted its
component to HOBART and will not deal directly with a first user then HOBART will cooperate with the first user
in the presentation of a claim to such manufacturer. Under NO circumstances does HOBART assume any liability
for any warranty claim against or warranty work done by or in behalf of any manufacturer of the foregoing
components.

5. This warranty is extended by HOBART only to the purchaser of new PRODUCTS from HOBART or one of its

authorized distributors. The PRODUCTS purchased under this warranty are intended for use exclusively by the
buyer and his employees and by no other persons and, therefore, there shall be no third party beneficiary to this
warranty.

6. A claim of defects in any PRODUCT covered by this warranty is subject to HOBART factory inspection and

judgment. HOBART’S liability is limited to repair of any defects found by HOBART to exist, or at HOBART’S
option the replacement of the defective product, F.O.B. factory, after the defective product has been returned by the
purchaser at its expense to HOBART’S shipping place. Replacement and exchange parts will be warranted for the
remainder of the original Warranty, or for a period of ninety (90) days, whichever is greater.

7. UNDER NO CIRCUMSTANCES whatsoever shall HOBART and its authorized distributors be liable for any

special or consequential damages, whether based on lost goodwill, lost resale profits, work stoppage impairment
of other goods or otherwise, and whether arising out of breach of any express or implied warranty, breach of
contract, negligence or otherwise, except only in the case of personal injury as may be required by applicable law.

8. Continued use of the PRODUCT(S) after discovery of a defect VOIDS ALL WARRANTIES.

9. Except as authorized in writing, this warranty does not cover any equipment that has been altered by any party

other than HOBART.

10. THERE ARE NO WARRANTIES WHICH EXTEND BEYOND THE DESCRIPTION ON THE FACE HERE

OF. HOBART MAKES NO WARRANTIES, EXPRESSED OR IMPLIED, OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE.

11. HOBART neither assumes nor authorizes any person to assume for HOBART any liability in connection with the

PRODUCTS sold, and there are no oral agreements or warranties collateral to or affecting this written Warranty.
This warranty and all undertakings of HOBART thereunder shall be governed by the laws of the State of Ohio,
United States of America.

Index: 990223
Replaces: 980601

AT ALL TIMES, SAFETY MUST BE CONSIDERED AN IMPORTANT FACTOR IN THE INSTALLATION,

SERVICING AND OPERATION OF THE PRODUCT, AND SKILLED, TECHNICALLY QUALIFIED

PERSONNEL SHOULD ALWAYS BE EMPLOYED FOR SUCH TASKS.

WARNING

OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

Safety Warnings and Cautions

WARNING

IMPORTANT

WARNING

ELECTRIC SHOCK can KILL. Do not touch live electrical parts.
ELECTRIC ARC FLASH can injure eyes, burn skin, cause equipment damage, and

ignite combustible material. DO NOT use power cables to break load and prevent tools
from causing short circuits.

IMPROPER PHASE CONNECTION, PARALLELING, OR USE can damage this and
attached equipment.

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.

CALIFORNIA PROPOSITION 65 - DIESEL ENGINES. Diesel engine exhaust and
some of its constituents are known to the State of California to cause cancer, birth
defects and other reproductive harm.

1) General

Equipment that supplies electrical power can cause serious injury or death, or damage to other equipment or
property. The operator must strictly observe all safety rules and take precautionary actions. Safe practices
have been developed from past experience in the use of power source equipment. While certain practices
below apply only to electrically-powered equipment, other practices apply to engine-driven equipment, and
some practices to both.

2) Shock Prevention

Bare conductors, 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, procedure s,
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,
and use insulating gloves when dampness or sweat cannot be avoided. Keep clothing dry, and never work
alone.

a) Installation and Grounding of Electrically Powered Equipment

Equipment driven by electric motors (rather than by diesel or gasoline engines) must be installed and
maintained in accordance with the National Electrical Code, ANSI/NFPA 70, or other applicable
codes. A power disconnect switch or circuit breaker must be located at the equipment. Check the
nameplate for voltage, frequency, and phase requirements. If only 3-phase power is available,
connect any single-phase rated equipment to only two wires of the 3-phase line. DO NOT CO NNECT
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.

April 01, 2005 Safety Warnings

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

Always connect the grounding lead, if supplied in a power line cable, to the grounded switch box or
building ground. If not provided, use a separate grounding lead. Ensure that the current (amperage)
capacity of the grounding lead will be adequate for the worst fault current situation. Refer to the
National Electrical Code ANSI/NFPA 70 for details. Do not remove plug ground prongs. Use correctly
mating receptacles.

b) Output Cables and Terminals

Inspect cables frequently for damage to the insulation and the connectors. Replace or repair cracked
or worn cables immediately. Do not overload cables. Do not touch output terminal while equipment is
energized.

3) Service and Maintenance

This equipment must be maintained in good electrical condition to avoid hazards stemming from
disrepair. Report any equipment defect or safety hazard to the supervisor and discontinue use of the
equipment until its safety has been assured. Repairs should be made by qualified personnel only. Before
inspecting or servicing this equipment, take the following precautions:

a) Shut off all power at the disconnecting switch, or line breaker, or by disconnecting battery, before

inspecting or servicing the equipment.

b) Lock switch OPEN (or remove line fuses) so that power cannot be turned on accidentally.
c) Disconnect power to equipment if it is out of service.
d) If troubleshooting must be done with the unit energized, have another person present who is trained

in turning off the equipment and providing or calling for first aid.

4) Fire And Explosion Prevention

Fire and explosion are caused by electrical short circuits, combustible material near engine exhaust
pipes, 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.

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 opening fuel tank cap. DO NOT
completely fill tank, because heat from the equipment may cause fuel expansion overflow. Remove

April 01, 2005 Safety Warnings

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

all spilled fuel IMMEDIATELY, including any that penetrates the unit. After clean-up, open equipment
doors and blow fumes away with compressed air.

5) Toxic Fume Prevention

Carbon monoxide - Engine exhaust fumes can kill and cause health problems. Pipe or vent the exhaust
fumes to a suitable exhaust duct or outdoors. Never locate engine exhausts near intake ducts of air
conditioners.

6) Bodily Injury Prevention

Serious injury can result from contact with fans or hot spots inside some equipment. Shut DOWN such
equipment for inspection and routine maintenance. When equipment is in operation, use extreme care in
doing necessary trouble-shooting and adjustment. Do not remove guards while equipment is operating.

7) Medical and First Aid Treatment

First aid facilities and a qualified first aid person should be available for each shift for immediate treatment
of all injury victims. Electric shock victims should be checked by a physician and taken to a hospital
immediately if any abnormal signs are observed.

EMERGENCY

FIRST AID

Call physician immediately. Seek additional assistance. Use First Aid techniques
recommended by American Red Cross until medical help arrives.

IF BREATHING IS DIFFICULT, give oxygen, if available, and have victim lie down.
FOR ELECTRICAL SHOCK, turn off power. Remove victim; if not breathing, begin

artificial respiration, preferably mouth-to-mouth. If no detectable pulse, begin external
heart massage. CALL EMERGENCY RESCUE SQUAD IMMEDIATELY.

8) Equipment Precautionary Labels

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

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60CU24 / Series 500060C / 400 Hz. Generator Set

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

Introduction

This manual contains operation and maintenance information for a 60CU24, 400 Hz Generator Set
manufactured by ITW GSE Group, Hobart Ground Power, 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 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 five chapters plus an appendix. Each chapter is divided into as many sections as
required. Each new section starts with page 1. Each page is identified by chapter, section and page number,
which are located in the lower, outside corner. When information located in another portion of the manual is
referred to, its location is identified by a chapter, section, and paragraph or figure number.

For example: “(see Section 2-3, Paragraph 1.a.)” refers to information located in Chapter 2, Section 3,
Paragraph 1.a. If a chapter and section are not indicated in a reference, the referenced material is located in
the same section as the reference, for example: “(see Paragraph 1.a.).”

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 5.

The Appendix is the last section. Its contains a list of available options that may be purchased with that unit.
Items on the list with check marks next to them, have been added to the standard unit per the customers
order. Literature for each option follows. The Appendix will help control the information in the manual:
making it unique to the unit purchased.

Contents of the manual is arranged as follows:

Chapter 1. Description/Operation
Chapter 2. Servicing/Troubleshooting
Chapter 3. Overhaul/Major Repair
Chapter 4. Illustrated Parts List
Chapter 5. Manufacturer’s Literature
Appendix A Options

April 01, 2005 Introduction

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

If you have any questions concerning your Hobart Ground Power equipment, immediately contact our Service
Department by mail, telephone, FAX, or E-Mail.

Write: ITW GSE Group

Hobart Ground Power
Service Department
1177 Trade Road East
Troy, Ohio 45373
U.S.A.

Call Inside U.S.A.: [phone] (Parts)

[phone] (Service)

Call From Foreign Countries: [phone] (Parts)

[phone] (Service)

FAX Inside U.S.A. [phone]
FAX From Foreign Countries: [phone]
E-Mail : [e-mail]
Web Page : www.itwgsegroup.com

April 01, 2005 Introduction

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Table of Contents

Chapter 1 Description/Operation Chapter-Section/Page#

Section 1

Section 2

Section 3

Chapter 2 Servicing / Troubleshooting Chapter-Section/Page#

Section 1

Section 2

Description 1-1/1

General
Orientation
Optional Equipment - Appendix A
Special Features
Canopy
Engine and Generator
Control Box Assembly
Power Module Panel Assembly
Cold Weather Starting System

Preparation for Use, Storage or Shipping 1-2/1

Preparation For Use
Tips on Cold Weather Starting
Preparation For Storage
Preparation For Shipment

Operation 1-3/1

General
400 Hz. Operation Procedure
DC Operation Procedure

Maintenance Inspection/Check 2-1/1

General
Maintenance Schedule
Inspection / Check

Maintenance Procedures 2-2/1

General
Lubrication
Servicing The Air Cleaner
Engine Fuel
Engine Fuel System

1-1/1
1-1/1
1-1/2
1-1/2
1-1/2

1-1/4
1-1/10
1-1/21
1-1/22

1-2/1

1-2/3

1-2/3

1-2/5

1-3/1

1-3/1

1-3/6

2-1/1

2-1/1

2-1/3

2-2/1

2-2/1

2-2/5

2-2/6

2-2/7

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60CU24 / Series 500060C / 400 Hz. Generator Set

Section 2
(cont.)

Section 3

Section 4

Engine Cooling System
Generator Maintenance
Drive Belt

Adjustments / Tests 2-3/1

General
Testing the 400 Hz. Generator Set
Generator Set Adjustments
Generator and Exciter Test
Diode Test
Testing the Transformer-Rectifier

Troubleshooting Procedures

General
Equipment for Troubleshooting
Parts Replacement
400 Hz. Test Values
Check Connections and Leads
Engine Troubleshooting
Illustrations
Connection and Schematic Diagrams
GPU Control Monitoring

Troubleshooting Charts

…Engine Controls
…Generator Excitation Circuits
…No. 1 Load Contactor Operating Circuit
…No. 2 Load Contactor Operating Circuit
…Protective Circuit
…Generator
Troubleshooting Tables – GPU Commands
Troubleshooting Tables – GPU Faults

2-2/10
2-2/13
2-2/13

2-3/1

2-3/1
2-3/12
2-3/15
2-3/16
2-3/16

2-4/1

2-4/1

2-4/1

2-4/2

2-4/2

2-4/2

2-4/2

2-4/2

2-4/3
2-4/11
2-4/11
2-4/14
2-4/15
2-4/17
2-4/19
2-4/20
2-4/22
2-4/26

Chapter 3 Overhaul / Major Repair Chapter-Section/Page#

Section 1

Exciter Armature 3-1/1

General
Exciter Armature
Exciter Armature Replacement
Installation Exciter Armature

3-1/1

3-1/2

3-1/3

3-1/6

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60CU24 / Series 500060C / 400 Hz. Generator Set

Section 2

Section 3

Dual Bearing Flexible Coupling

General
Disassembly
Coupling Service
Coupling Installation
Reassemble Engine and Generator
Run-in and Periodic Check

Generator Assembly

General
Generator Assembly Removal
Generator Assembly Installation

3-2/1

3-2/1

3-2/4

3-2/5

3-2/6

3-2/7

3-3/1

3-3/1

3-3/2

Chapter 4 Illustrated Parts List Chapter-Section/Page#

Section 1

Section 2

Section 3

Introduction 4-1/1

General
Purpose
Arrangement
Explanation of Parts List

Manufacture's Codes 4-2/1

Explanation of Manufacture's (Vendor) Code List

Illustrated Parts List 4-3/1

Explanation of Parts List Arrangement
Symbols and Abbreviations
Figure 1: General Assembly
Figure 2: Frame Assembly
Figure 3: Canopy Assembly
Figure 4: Internal Components
Figure 5: Control Box Door Panel Assembly
Figure 6: Control Box Interior Components
Figure 7: Control Switch Panel Components
Figure 8: Push-Buttons Details
Figure 9: 400 Hz. Power Module Assembly
Figure 10: Cooling System Components

4-1/1

4-1/1

4-1/1

4-1/1

4-2/1

4-3/1

4-3/1

4-3/2

4-3/6

4-3/8
4-3/10
4-3/12
4-3/14
4-3/16
4-3/18
4-3/20
4-3/22

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60CU24 / Series 500060C / 400 Hz. Generator Set

Section 3
(cont.)

Figure 11: Fuel System Components
Figure 12: 12 VDC Battery System
Figure 13: Air Cleaner Components
Figure 14: Engine Components
Figure 15: Engine Exhaust Components
Figure 16: Generator Assembly
Figure 17: Trailer Components

Numerical Index 4-4/1Section 4

Explanation of Numerical Index

Chapter 5 Manufacture's Literature
Appendix A Options/Features
Wet Stacking
Unusual Service Conditions

4-3/24
4-3/26
4-3/28
4-3/30
4-3/32
4-3/34
4-3/36

4-4/1

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60CU24 / Series 500060C / 400 Hz. Generator Set

Chapter 1 Description/Operation

Section 1 Description

1) General

Hobart Ground Power part of the ITW GSE Group in Troy, Ohio, manufactures the basic generator set
covered in this manual. Is rated at 60 kVA and designed to produce and deliver 115/200-volt, 400 Hz, 3­phase AC, or 28.5V DC power to a parked aircraft or to Hobart approved test banks only.

The number 500060C identifies the “model or series” of the GPU. The part number is followed by a
different dash number that separates the basic units available. Figure 1 uses the part number to identify
the variations covered in this manual.

Part & Dash Number Model Description

500060C-001 Single Output, Trailer Mounted (Stainless Steel Fuel Tank)
500060C-002 Dual Output, Trailer Mounted (Stainless Steel Fuel Tank)
500060C-003 Single Output, Fixed/Truck Mounted (Stainless Steel Fuel Tank)
500060C-004 Dual Output, Fixed/Truck Mounted (Stainless Steel Fuel Tank)
500060C-005 Single Output, Trailer Mounted, 28.5V DC TR (Stainless Steel Fuel Tank)
500060C-006 Single Output, Fixed/Truck Mounted, 28.5V DC TR (Stainless Steel Fuel Tank)
500060C-007 Single Output, Fixed Mounted, 28.5V DC TR (Special) (Stainless Steel Fuel Tank)
500060C-008 Single Output, Trailer Mounted, Digital AC Meters (Stainless Steel Fuel Tank)
500060C-009 Single Output, Fixed/Truck Mounted, Digital AC Meters (SS Fuel Tank)
500060C-010 Single Output, Trailer Mounted, 28.5V DC TR, Digital AC/DC Meters(SS Tank)
500060C-011 Single Output, Fixed/Truck Mounted, 28.5V DC TR, Digital AC/DC Meters (SS Tank)
500060C-101 Single Output, Trailer Mounted (Composite Fuel Tank)
500060C-102 Dual Output, Trailer Mounted (Composite Fuel Tank)
500060C-103 Single Output, Fixed/Truck Mounted (Composite Fuel Tank)
500060C-104 Dual Output, Fixed/Truck Mounted (Composite Fuel Tank)
500060C-105 Single Output, Trailer Mounted, 28.5V DC TR (Composite Fuel Tank)
500060C-106 Single Output, Fixed/Truck Mounted, 28.5V DC TR (Composite Fuel Tank)
500060C-107 Single Output, Fixed Mounted, 28.5V DC TR (Special) (Composite Fuel Tank)
500060C-108 Single Output, Trailer Mounted, Digital AC Meters (Composite Fuel Tank)
500060C-109 Single Output, Fixed/Truck Mounted, Digital AC Meters (Composite Fuel Tank)
500060C-110 Single Output, Trailer Mounted, 28.5V DC TR, Digital AC/DC Meters (C Tank)
500060C-111 Single Output, Fixed/Truck Mounted, 28.5V DC TR, Digital AC/DC Meters (C Tank)

Series 500060C Generator Set Part Number Descriptions

Figure 1

2) Orientation

For purpose of orientation, the radiator is considered to be at the FRONT of the unit. The generator and
controls are at the REAR. LEFT and RIGHT are determined by standing at the REAR end facing the
control box.

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60CU24 / Series 500060C / 400 Hz. Generator Set

3) Optional Equipment - Appendix A

Chapters 1 through 5 of this Operation and Maintenance Manual identifies only the “strip down” version of
the 60CU24 generator set. A list of optional equipment which make this manual unique to the generator
set that you have purchased, appears in Appendix A. A few items included in Appendix A are cable trays,
trailers, 28-volt DC power transformer-rectifiers, etc.

4) Special Features

The generator set has special features that are described more fully under the assemblies in which they
appear. Three features: protective monitor, voltage regulator and electric governor are mentioned here
and described briefly.

Protective Monitoring

The protective monitoring system receives signals from the fault sensing units in the generator output
circuit and functions to cause the load to be disconnected from the generator if an abnormal condition
of voltage, frequency, or load develops.

a) Voltage Regulator

A microprocessor-type, adjustable voltage regulator provides automatic voltage regulation at the
aircraft. The regulator is also adjustable for a variety of output cable sizes and lengths.

b) Engine Electronic Control Module

The engine is equipped with an electronic control module that monitors, records, and controls engin e
performance.

5) Canopy

A sheet metal enclosure, identified as a canopy, provides protection for the engine, generator and
electrical controls. The canopy is designed to reduce the operational noise level in the immediate area of
the machine.

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60CU24 / Series 500060C / 400 Hz. Generator Set

Physical Basic Unit (Fixed Mount) Trailer Mounted Unit

Length 68 in. (172.7 mm) 94.5 in. (240 mm)
Width 37 in. (94 mm) 67 in. (170.1 mm)
Height 46 in. (116.8 mm) 62 in. (157.5 mm)
Weight (Single AC output only) 2595 lb. (1107 kg.) 3070 lb. (1393 kg.)
Weight (Dual AC output only) 2700 lb. (1225 kg.) 3175 lb. (1440 kg.)

Weight (AC & DC outputs) 2875 lb. (1304 kg.) 3350 lb. (1519.5 kg.)

AC GENERATOR

Output power rating 60 kVA 48 kW
Output voltage 115 / 200 VAC
Rated load capacity 174 Amps
Frequency 400 Hz.
Power factor 0.8
Duty Cycle 100%
Operating speed 2400 RPM
Overload capacity, both outputs

217.5 Amps
125% rated load
Output cable size 2/0

Specifications and Capabilities

Figure 2 (Sheet 1 of 2)

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60CU24 / Series 500060C / 400 Hz. Generator Set

GENERATOR PROTECTIVE SYSTEM

Over voltage Trips at 126 volts after a 1 second time delay.

Trips at 140 volts in 160 milliseconds.

Trips at 180 volts in 50 milliseconds.
Under voltage Trips at any voltage below 100 volts after 7 seconds.
Over frequency Trips at any value between 420 Hz and 480 Hz after a 5 second time

delay. Trips immediately at any frequency exceeding 480 Hz.
Under frequency Trips at 380 Hz. or less after a 7 second time delay.
Overload time delay Trips in app roximately 5 minutes at 125% load of 90 kVA on either

output or 125% of 120 kVA on both outputs combined.

DC OUTPUT (OPTIONAL, SEE APPENDIX A)

Output Voltage 28.5 VDC
Amps (Continuous) 600 A
Amps (Peak/Starting/Overload) 2700 A for 2 seconds

2000 A for 10 seconds
1500 A for 30 seconds
1200 A 90 seconds
750 A 600 seconds

ENGINE

Manufacturer Cummins Engine Company
Model No. QSB4.5
Type In-Line 4 cylinder, 4 cycle diesel, electronic controlled
Bore and Stroke 4.02 in. x 5.42 in. (102 mm x 138 mm)
Displacement 275 in3 (4.5 L)
Horsepower 110 hp (82 kW)
Idle speed 1000 ± 50 rpm
High speed limiting 2750 ± 75 rpm
Normal governed speed 2400 rpm
Firing Order 1-3-4-2
Electrical system 12 VDC
Ground Negative
Lubricating oil capacity (w/ filter) 10 quarts (9.5 liters)
Coolant capacity system 38 quarts (36 liters)

Specifications and Capabilities

Figure 2 (Sheet 2 of 2)

6) Engine and Generator

The engine and generator comprise the principal components of the gene rator set. They are mounted on
the welded steel frame of the chassis. The engine coolant radiator is also mounted on the frame just
forward of the engine-generator combination. Figures 4 and 5 are illustrations showing the location of all
major components and sub-assemblies.

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a) Basic Engine

The basic diesel engine is a in-line 4-cylinder, electronically controlled engine rated at 110
horsepower. See Figure 2 for specifications and capabilities.

b) Engine Manufacturer’s Equipment

As received from the engine manufacturer, the engine includes the following equipment, which is
more fully described in the engine manufacturer’s operation manual.

(1) Electrical System

The 12 VDC electrical generating and starting system include an alternator, voltage regulator,
and starter with solenoid switch.

(2) Fuel Filter

The fuel filter is a spin-on disposable, vacuum type connected between the fuel lift pump and
injector pump.

CAUTION

The use of low lubricity fuels can shorten life and/or damage the engine’s fuel pump.
Only diesel fuel is recommended by the engine manufacturer.

(3) Oil Filter

The engine oil filter is a spin-on, full-flow type, located on the left side of the engine near the front.

(4) Pre-programmed Electronic Control Module (ECM)

The ECM is a pre-programmed engine control module, mounted directly to the engine block.

c) Engine-cooling fan

The engine fan is designed to blow air outward through the radiator, rather than pulling the air inward
as a conventional fan does.

d) Hobart Installed Equipment

This generator set is modified at Hobart Brothers by the addition of the following equipment:
(1) Shut Down/Reset device

In addition to the other devices provided by the engine manufacturer, the factory also added an
engine shutdown/reset feature.

a EMERGENCY SHUTDOWN/RESET SWITCH (S28)

The emergency shutdown switch has two purposes. One is to reset the starting circuit
following a failed starting sequence. The other is to provide instant manual shut off of the
generator set by disconnecting power to the ECM through the control box. It is located on the
left side of the generator set near the control box (See Figure 3)

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60CU24 / Series 500060C / 400 Hz. Generator Set

To operate the EMERGENCY SHUTDOWN/RESET SWITCH:

• Push button in until engine stops or until button travel stops

• Pull the button back out to reset

b Coolant high temperature shutdown system

The coolant temperature shutdown system consists of a factory supplied temperature switch.
This switch is monitored by the microprocessor on the EIB (“Engine Interface Board”) PC
Board, which will stop the engine if the temperature reaches 230º F (110º C).

c Oil pressure shutdown system

The oil pressure shutdown system consists of a factory supplied oil pressures switch. This
switch is monitored by the microprocessor on the EIB (“Engine Interface Board”) PC Board,
which will stop the engine if the oil pressure is under 12 PSI (82.7 kPA).

(2) Air cleaner (Figure 6)

The diesel engine air cleaner is so constructed that air enters through its cylindrical body, and
then is filtered in the process before being passed onto the engine turbo-charger assembly. An
air cleaner service indicator device is mounted on the air cleaner assembly to monitor the airflow
into the air cleaner. As the air cleaner becomes filled with dust, dirt, and carbon, the intake
system airflow becomes increasingly restricted. This restriction causes a diaphragm inside the
indicator to move toward an electrical contact. When the maximum allowable restriction level is
reached, the circuit closes and the air cleaner indicator fault appea rs on the control panel fault
display to warn the operator that the air cleaner must be changed. The electrical indicator
automatically resets when the restriction level drops sufficiently.

e) Engine faults

The following is a table listing faults, which may occasionally occur. Column two of the table explains
what happens in the engine’s circuitry when the fault occurs, and column three tells how to return the
generator set to service once the problem is solved. Refer to Chapter 2 for more details on all other
faults.

f) Generator

The 400 Hz generator is a brushless, revolving field, three-phase, alternating current type. The
generator set covered by this manual is a dual-bearing type. The front end of the rotor shaft extends
forward beyond the front bearing and is attached to the engine flywheel by a flexible coupling
assembly. The rear end of the rotor shaft extends rearward beyond the rear bearing and into the
exciter stator housing. The exciter rotor is mounted on this shaft extension with a key and is secured
by a washer and 1/2-13 thread 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 voltage regulator
PC board (REG). A centrifugal, radial-blade fan, which is part of the flexible 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 assembly is bolted to the engine flywheel housing.

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ENGINE FAULTS

Engine Fault Condition What Occurs How To Reset

Over temperature or low oil
pressure

Shuts down the engine, and will be
indicated will appropriate fault
code.

Low fuel warning and shutdown Turns on the low fuel indication on

the fault code meter. The GPU is
programmed at the factory to warn

1

/4 tank and to shutdown at 1/8

at
tank.

Clogged air cleaner or other
restriction in the combustion air

Turns on the air cleaner restriction
indicating fault code.

inlet.

Engine Faults

Figure 3

a) Press the engine stop button to

reset the fault code and reset the
protective system.
b) Or use E-STOP button for
immediate reset.
a) The low fuel fault indicating
function must be reset by
pressing the engine stop button
Fuel must be added prior to
attempting another engine start.
b) Or use E-STOP button for
immediate reset.
a) Press the engine stop button.
The restriction must be removed
prior to attempting another engine
start.
b) Or use E-STOP button for
immediate reset.

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7

8

9

1

2

6

4

3

10

1. Control Panel

2. Operator’s Push-Button Panel

3. Output Cable Location

4. Front Axle Assembly

5. Rear Axle Assembly

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5

6. Emergency Stop Switch (S28)

7. Exhaust Outlet

8. Canopy

9. Radiator End

10. Generator End

General Assembly of Generator Set

Figure 4

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4 3 2 1

1. Radiator

2. Cummins QSB Engine

3. Air Cleaner

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5

6

4. Control Box

5. Fuel Tank

6. Generator

Main Components of Generator Set

Figure 5

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Service Indicator

Air Cleaner

Air Cleaner and Service Indicator

Figure 6

7) Control Box Assembly

The control box is a sheet metal enclosure that houses and provides mounting facilities for engine and
generator controls and monitoring equipment.

a) Control Panel (Figure 7 and 8)

The control system is divided into two sections. On the left side of the control panel, as one faces it,
are engine meters. On the right side of the control panel are generator meters. Below the control
panel are push-button switches for operating the engine and generator.

(1) Panel lights and panel light push-button switch (S74)

Meters are lighted from inside the control panel. The “LAMPS” push-button switch controls the
lights.

(2) Engine hour meter (M4)

The hour meter is electrically driven from the 12 VDC battery system. The hour meter measures
and records the engine’s running time and will record up to 9999.9 hours on five revolving dru ms.
It is only functional when the engine is running.

(3) Engine oil pressure gage (M24)

The oil pressure gage is an electrical type that is connected by a wire to an oil pressure sensor
installed in the engine lubricating system. The range is 0 to 125 PSI (0 to 862 kPA).

(4) Engine ON indicating light (DS58)

When the engine is running at idle speed, a green indicating light, within the “ENGINE START”
push button switch, flashes at a rate of 1 second on, 1 second off. When the engine is running at
rated speed, the light will stay on continuously.

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3 4

12

6 8 7,10 10,1110,12

5

139 10,15 10,1617

1. Fuel Gage (M13)

2. Front Panel

3. Engine Coolant Temperature Gauge (M24)

4. Running Time Meter (M4)

5. Oil Pressure Gage (M25)

6. Battery Voltmeter (M5)

7. Frequency Meter (M3)

8. Control Panel Label

9. Fault Code Meter (M6)

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10. Strip Lights (DS60-DS62) (3) [Not Shown]

11. AC Generator Ammeter (M1)

12. AC Voltmeter (M2)

13. Adjustable Grip Latch

14. Control Panel Door Hinge [Not Shown]

15. DC Voltmeter [Optional with TR]

16. DC Ammeter [Optional with TR]

17. Front LED PC Board (A5) [Shown Opposite Side]

Control Panel Door

Figure 7

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1. Meter Selector Switch (S3)

2. Test/Reset Switch (S77)

3. Engine Stop Switch (S76)

4. DC Starting Current Switch (S431) [Optional with TR]

5. DC Output Contactor Switch (S430) [Optional with TR]

Control Push-Button Switch Panel

Figure 8

1245678910 3

6. AC Output No. 2 (S275) [if applicable]

7. AC Output No. 1 (S75)

8. Engine Start Switch (S24)

9. Air Intake Heater Switch (S79)

10. Panel Light Switch (S74)

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1

2

4

5

7 6

89

10

1. Engine Specific PC Board [ESB] (A1)

2. Engine Interface PC Board [EIB] (A2)

3. Digital Control PC Board [CTL] (A3)

4. Voltage Regulator PC Board [REG] (A4)

5. Transformer-Rectifier PC Board [TRB] (A404) {Optional}

3

6. +5, -12 VDC Power Supply (PS1)

7. Circuit Breaker Support Bracket

8. Marker Lights Circuit Breaker, 10 A (CB1)

9. Engine Circuit Breaker, 10 A (CB4)

10. Controls Circuit Breaker, 5 A (CB7)

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Control Box Interior Components

Figure 9

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(5) Engine coolant temperature gage

The temperature gage is an electrical type that is connected by a wire to a water temperature
sensor installed in the engine cooling system. The gage indicates engine coolant temperature in
the range of 100-280 º F (38-138º C).

(6) “ENGINE START” push-button switch (S24)

The “ENGINE START” push-button switch, when pressed, connects 12 VDC power to the starter
solenoid coil, which actuates the solenoid switch to connect power to the engine starting motor.
The 12 VDC power is supplied directly to the engine ECM and the oil pressure shutdown switch is
bypassed (This bypass is necessary for engine starting because the low oil pressure switch is
CLOSED until the engine is running normally). The green indicator light with blink.

When pressed a second time, this push-button switch provides a signal to the ECM to adjust the
engine speed to 2400 RPM. The green indicator light will glow continuously. At the same time, a
ground signal is provided to the regulator, enabling the generator to build up voltage for 400-Hz
generator output. Pressing the push-button switch once more removes these signals and the
engine reverts to idle speed and a blinking green indicator light.

(7) “ENGINE HEATER” push-button switch (S79)

The “ENGINE HEATER” push-button switch activates the standard cold starting aid (manifold air
intake heater), which is totally controlled by the engine’s ECM. Once the heater is activated, the
engine’s ECM will control the operation. The heater typically stays on for a period of
approximately 30 seconds, which is indicated by the light on the push-button. When the light
goes out, the engine is ready to start. Starting a cold engine without first warming the engine will
lead to excessive white smoke exhaust and the engine may be hard to start.

(8) “ENGINE STOP” push-button switch (S76)

When the “ENGINE STOP” push-button switch is pressed, the red indicator will glow. Then a 3 ­5 minute delay will occur to permit the turbo and other engine components to cool evenly. After
the delay, power is disconnected from the engine ECM causing the engine to shut down.

(9) Engine voltmeter (M5)

The ammeter indicates the direction and value of current flow from or to the 12 VDC battery. Its
graduated 10 V to 16 V.

(10) Engine fuel gage (M13)

An electric fuel gauge receives its controlling signal from a sending unit in the fuel tank. 12 VDC
operating power is supplied to the fuel gauge when the “ENGINE START” push-button switch is
pressed. The fuel level can also be checked when the unit isn’t running by pressing the panel
light “LAMPS” push-button switch.

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(11) Fault Code meter and “TEST/RESET” push-button switch (M6, S77)

The function of the fault code meter is to indicate to the operator, that an abnormal condition of
over voltage, under frequency, etc. occurred, which caused the protective monitoring system to
function. When one of the circuits are activated, it shows the code on the fault code meter. The
fault will remain on for a short period of time or until the “TEST/RESET” push-button switch is
pressed. Pressing the “TEST/RESET” push-button switch can also test the fault code meter
operation. A meter test should be performed only when disconnected from a load, as the
contactor(s) will open during the test cycle.

(12) Engine systems fault codes

Fault codes will be shown to warn the operator of abnormal engine operations that must be
corrected. These indicators are over temperature, air cleaner restriction, low oil pressure, and
low fuel indication.

(13) AC Generator output monitors (meters)

Three instruments, a frequency meter, a voltmeter, and an ammeter monitor the generator output.
The frequency meter is an analog type and indicates the frequency of the generator output
alternating current in the range of 360 to 440 Hz (cycles per second). The voltmeter indicates the
generator output voltage in each phase-to-neutral (A-N, B-N and C-N) or phase-to-phase (A-B, B­C and C-A) as selected by the “METER SELECT” switch. The voltmeter has a scale of 0 to 300
V. The ammeter has a scale of 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 “METER SELECT” switch. The
ammeter current transformers, located in the output power module circuit, lower the output load
current to a lesser value, of definite ratio, which is sent to the Voltage Regulator PC Board (REG).
The ammeter dial scale is numbered so that the pointer will indicate the true load current value.

(14) Load contactor indicating lights [Yellow # 1 and Orange # 2] (S75, S275)

Indicating lights within the respective contactor control push-button switches (“OUTPUT NO. 1”
and or “OUTPUT NO. 2”, if applicable) glow when the circuit is energized, indicating that power
is available at the plug. When the load contactor opens for any reason, the light is turned OFF.

(15) Front LED Display (A5)

The front LED display signifies to the operator which voltage (A-N, A-B, etc…) and amperage are
shown on the meters, as well as, when “EF BY-PASS” is present or bypassed. This “EF BY-
PASS” indicator serves to warn the operator that if the plug interlock system was by-passed any
exposed cable may be live.

(16) DC Generator output monitors (meters) [Optional with TR, Reference Appendix A]

Two instruments, a voltmeter and an ammeter, monitor and display the transformer-rectifier’s
output. The voltmeter and ammeter meters are both analog type and indicate the output voltage
from 0 to 50 VDC and the amperage from 0 to 2500 A.

(17) “STARTING CURRENT” Switch (S431) [Optional with TR, Reference Appendix A]

Each time the “STARTING CURRENT” push-button switch is pressed, the BLUE indicator will
glow. The present current limiting amperage setting will be displayed on the fault code meter for
a short time delay, before incrementing, at 100 A increments, up to 2500 A. Once 2500 A has
been reached, the incrementing will start over from the beginning.

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(18) “DC OUTPUT” Contactor Switch (S430) [Optional with TR, Reference Appendix A]

Each time the “DC OUTPUT” push-button switch is pressed, the BLUE indicator will glow when
the circuit is energized, indicating that power is available at the plug. When the load contactor
opens for any reason, the light is turned OFF.

b) Control Box Interior Components (Figure 9)

(1) EF Bypass switches (located on CTL)

For each load contactor circuit, a single-pole, single-throw “EF1 BYPASS” for “OUTPUT 1” (or
“EF2 BYPASS” for “OUTPUT 2”, if applicable) provides a means of bypassing the 28 VDC
interlock circuit for the contactor when supplying power to a load bank or to an aircraft not
equipped with a plug interlock system.

(2) Regulated-diagnostic switch (located on the REG)

When the “REGULATED/DIAGNOSTIC” switch is in the “REGULATED” (down) position, the
generator output voltage is regulated by the PC board for 115/200 VAC output to an aircraft.
When this switch is placed in the “DIAGNOSTIC” (up) position, 12 VDC is applied to the
generator exciter with the engine running at rated RPM, in order to check the operation of the
generator. This is done to determine if a particular power output malfunction is caused by a
defective generator or by a defective voltage regulator. When this switch is in the
MAINTENANCE position, no current is supplied to the generator exciter. In this condition, a low­level, unregulated voltage of approximately 30 VAC will be produced at the generator output
terminals due to the residual magnetism of the exciter.

(3) Circuit breakers (CB1, CB4, CB7)

A 10-ampere “ENGINE” circuit breaker, protects the 12 VDC engine electrical and fault circuits,
and another 10-ampere “MARKER LIGHTS” circui t breaker p rotects the 12 VDC lighting system.
A 5-ampere “CONTROL” circuit breaker protects the 12 VDC control system.

(4) Digital Control PC Board [CTL] (A3)

The digital control PC board (see Figure 10) is the center for all communications throughout the
entire control system. All push-button panel commands run through the digital control PC board
and communicates the commands to the appropriate area (i.e. other PC boards) in the control
system. The digital control PC board also controls the real time clock, monitors the over/under
voltage and overload protection, push-button panel indicator lights, generator output meters, EF
bypass switches, and communicates with the optional service tool.

(5) Engine Interface PC Board [EIB] (A2)

The EIB (see figure 11) is common between all engine models and monitors coolant temperature,
oil pressure, battery voltage, and fuel tank level monitoring. The EIB is also responsible for the
monitoring the warning switches for high coolant temperature, low oil pressure, hi gh air
restriction, and low coolant level (optional). The warning switches signal the EIB when a fault
occurs, which then the EIB relays this information to the CTL. The CTL will issue the command
to the system that fits the fault event.

The EIB also controls the power distribution in the control system, hour meter, lights, and the
engine starter operation.

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J54 Connector

PC Board Software

EF1 Bypass

EF2 Bypass (if applic able)

Digital Control PC Board

Figure 10

Service Tool Connect or

(6) Engine Specific PC Board [ESB] (A1)

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The ESB (see figure 12) is unique only to the engine model used in the GPU purchased. The
ESB is the primary interface between the control system and the engine’s electronic control
module. When the CTL senses the engine start button has been pressed it signals to the ESB,
which then communicates to the engine control module what mode of operation is required (idle
or rated speed).

The ESB controls the “FREQUENCY ADJUST” switch that is used to enable the “FREQUENCY
ADJUST ENABLE/DISABLE” potentiometer to test the over/under frequency fault limits of the
generator set system. The ESB also controls the “DATA REQUEST” button and diagnostic
indicator light to read the engine’s ECM diagnostic error codes.

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Starter Disable/Enable

J51 Connector

PC Board Software

Engine Interface PC Board

Figure 11

Engine Sta tus Switch

Frequency Adjustment &

Enable/Disable Switch

J52 Connector

Engine S tatus Lights PC Board Software

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Engine Specific PC Board

Figure 12

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Regulated/Diagnostic J53 Connector

PC Board Software

Voltage Adjustment, Coarse

Voltage Adjustment, Fine LDC Control

(7) Voltage regulator PC board [REG] (A4)

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Voltage Regulator PC Board

Figure 13

This voltage regulator PC board (see Figure 13) is designed to provide voltage regulation for a
three-phase, four-wire, 115/200-volt, 400-Hz brushless alternator. This regulator provides field
excitation power as required to meet varying alternator load conditions to hold the alternator
voltage constant. In addition, the voltage regulator PC board circuitry provides line drop
compensation. Any deviation of the alternator voltage from its set, regulated level is sensed at
the voltage regulator PC board. The sensing signal is compared to a reference signal, and, with
associated circuitry, varies the field power supplied to the rotary exciter.

a When the machine is started, and the engine is at rated speed, the rotary exciter is excited

from alternator residual magnetism through the half-wave rectifier-bridge, located on the
voltage regulator PC board assembly. As the rotary exciter voltage increases, alternator
excitation increases and the alternator voltage builds up. The sensing circuit of the voltage
regulator PC board then compares the input voltage to a reference voltage and adjusts the
field power of the rotary exciter to bring the voltage into regulation limits.

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b When the alternator is loaded, its terminal voltage decreases, lowering the rectified three-

phase voltage of the voltage sensing circuit. The sensing voltage is low in respect to its
reference voltage, causing the voltage regulator PC circuitry to increase the power to the field
of the rotary exciter. The alternator voltage increases until the voltage returns to its regulated
value.

c When a load is removed from the alternator, the alternator voltage ri ses. The rectified three-

phase voltage-sensing signal increases, causing this signal to be higher than the reference
signal. The associated voltage regulator circuitry causes the field power of the rotary exciter
to decrease, lowering the alternator voltage until the voltage returns to regulated value. The
line drop voltage compensation circuit consists of a current transformer on each phase of the
load circuit, and fixed resistance in parallel with each current transformer. The current
transformers detects the magnitude of current flowing through the power cables from the
alternator to its load and feeds a signal into the voltage regulator PC board. The PC board
processes this signal to change the output voltage proportional to the current draw. The
regulator output increases slightly so that the alternator output voltage is equal to the
regulated voltage plus the voltage drop in the lines. The line drop compensation
potentiometer may be adjusted to match exactly the voltage drop of the power cables
carrying the load current.

The under/over frequency protection, EF signal, and lost neutral detection are also monitored by
the REG and will signal the CTL when a fault has occurred. The CTL issues the appropriate
command that corresponds to the fault.

(8) Transformer-Rectifier PC Board [TRB] (A404) {Optional with TR, Reference Appendix A}

The TRB PC Board (see Figure 15) is only used when the optional 28.5 VDC transformer-rectifier
assembly is installed. The TR monitors the output voltage, output current, controls the input and
output contactors, and monitors all fault events associated with the DC output. When a fault event
does occur the TRB relays this information to the CTL. The CTL will issue the command to the
system that fits the fault event.

(9) +5, -12 VDC Power Source (PS1)

Supplies the internal power distribution of +5 VDC and –12 VDC into the control system.

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Control System Power Source

Figure 14

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PC Board Software

J401 Connector

Transformer-Rectifier PC Board

Figure 15

8) Power Module Panel Assembly (Figure 16)

The power module panel assembly sometimes referred to as the contactor panel, is located at the left
front of the machine under the control box. The panel assembly provides a means of connecting and
disconnecting generator output to and from the load (aircraft).

a) Load contactor(s)

The load contactor(s) each contain a magnetic operating coil and four sets of contacts. The three
larger contacts conduct three-phase AC generator output. A small contact set is connected to the
Digital Control PC Board (CTL) to activate the protective monitor circuit. Three-phase, 400-Hz
generator output power is conducted to the load contactors by 2/0 cables that pass through current
transformers.

b) Current transformers (CT1-CT3 or CT6 if 2

On each individual output a set of current transformers are used to monitor and control the line-drop
compensation, ammeter, and overload circuit.

nd

output installed)

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(1) Line-Drop Compensation

The current transformers detects the magnitude and power factor of current flowing from
generator to load. They feed a signal to the voltage regulator that interprets the signal and alters
the exciter field current as required to maintain a constant predetermined voltage at the load.

(2) Ammeter

The current transformers convert a current signal to a voltage signal, which is sent to the Voltage
Regulator PC Board (REG). The ammeter is really a voltmeter graduated and numbered in
amperes to show current proportional to the voltage signal received.

When there is overload on the output for more than 5 minutes (load exceeding 326 amperes per
output or 125% of rated load), the main overload sensing circuit sends signals the load the
contactor(s) circuit to open both load contactors.

(3) Overload, No 1 and/or No. 2 output (if applicable)

On each individual output the current transformers converts a current signal to a voltage signal.
The voltage signal is sent to the ammeter and to the overload monitoring circuit for that output.
The overload monitoring circuit will open the contactors when the output current rea ches 125% of
the normal rated output current. The monitoring circuit moniters each individual output, as well
as, the overall current for a dual output machines.

The following is a list of overload module characteristics:

• At 125% load the module will function in 5 minutes.

• At 150% load the module will function in 30 seconds.

• AT 200% load the module will function in 10 seconds.

NOTE: The overload protective system will function when any phase carries 123% to 127% of
rated load. All times are plus or minus 25% and are non-adjustable.

9) Cold Weather Starting System

CAUTION

The block heater kit is installed inside the enclosure of the engine/generator set, and is connected to the
cooling system of the diesel engine. Its purpose is to keep the coolant warm when the engine is shut
down for extended periods of time in cold weather, and thus permit the engine to start more quickly.

The block heater unit is mounted to the engine/generator frame with a bracket and attaching hardware.
Hoses, clamps, and fittings connect the block heater to the engine’s cooling system.

Mounted low in the system, a head pressure is maintained at the heater’s intake and a simple one-way
valve in the heater unit ensures the direction of coolant flow.

Drain the engine coolant system before working on the block heater. Afterwards, refill
the cooling system and bleed at highest point to remove any air locks.

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1

2

3

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1. Output #1 Contactor (S75)

2. Wire Harness

3. Output #2 Contactor (S275) (If Applicable)

Output Power Module Components

Figure 16

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Section 2 Preparation for Use, Storage, or Shipping

1) Preparation for Use

a) Inspection/Check

Inspect the unit thoroughly prior to operation.
(1) Remove blocking, banding, ties, and other securing material.
(2) Inspect exterior for shipping damage such as broken lights, damaged sheet metal, etc.
(3) Open all canopy doors and inspect interior for foreign material such as rags, tools, shipping

papers, etc.

(4) Check fuel, coolant, 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, corre ct by

tightening hose clamps, tube fitting, etc., as required.
(5) Check security of generator set retaining components.
(6) Check the following for sufficient quantity:

a Fuel

Press “LAMPS” push-button button to energize fuel gage when engine is stopped. Fuel is
supplied from a customer-furnished source.

NOTE: For recommended fuel specifications refer to the Engine Manufacturers Operation and
Maintenance Manual provided with this manual.

b Engine coolant

Remove radiator cap to check coolant level. Coolant level should be at the bottom of the filler
neck.

CAUTION

NOTE: For antifreeze protection, use a solution of 50% permanent antifreeze (Ethylene glycol) and

50% clean water.

Lubricating oil capacity (w/ filter) 10 quarts (9.5 liters)
Coolant capacity system 38 quarts (36 liters)

BE SURE the cooling system antifreeze solution is adequate to protect below the
lowest temperature expected.

ENGINE OIL AND COOLANT CAPACITIES

April 01, 2005 Chapter 1-2

Figure 1

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c Engine lubricating oil level

The oil gage rod has “H” high mark and “L” low level marks to indicate the operating
lubrication oil supply. Oil level should be kept as near the high mark as possible, without
going over it. See Figure 1 for capacity.

CAUTION

NOTE: See the Engine Manufacturer’s Operation Maintenance Manual for oil recommendations.

NEVER operate the engine with oil level below the “L” level mark or above the ”H”

level mark.

Oil Fill

Oil Fill and Oil Level Check Locations

Figure 2

Oil Level Check

d Check Batteries

Inspect the batteries for proper connection of the terminals and also check the electrolyte
level (if possible). Service or replace if necessary.

b) Installing Three-Phase AC Output Cables

The generator set may be shipped without aircraft cables. The load contactors, to which cables must
be connected, are located on the power module assembly (left side of the unit beneath the engine
control panel).

The conductor size recommended for AC output cables is 2/0 AWG. Use No. 12 size for control (E
and F) terminals. Large cables (A, B, C, and N) should be equipped with terminals having at least a
3/8-inch diameter, mounting holes. Mounting holes in the small leads (E and F) should be at least
1/4-inch diameter.

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60CU24 / Series 500060C / 400 Hz. Generator Set

To install AC output cables proceed as follows:
(1) Open control box door of the generator set and remove the lower panel.
(2) Remove Plexiglas cover in front of the power module assembly.
(3) Remove the cover panel on the cable tray covering the cable clamps.
(4) Loosen screws on cable clamps.
(5) Route cables through cable clamps, and up to the load side of the load contactor(s).
(6) Connect the phase cable terminal lugs to the appropriate terminal studs on the contactor(s): cable

lug “A” to terminal stud “A”, “B” to “B”, and “C” to “C”.
(7) Connect the cable’s neutral terminal lug securely to the neutral (ground) stud on the power

module assembly.
(8) Connect the “E” and “F” cables to the “E” and “F” studs on the power module assembly.
(9) Tighten clamp screws securely, but avoid damage to cable insulation.
(10) Replace Plexiglas cover panel, lower panel, and close canopy door.

2) Tips on Cold Weather Starting

a) Battery and Cables

To start in cold weather, a diesel engine must crank at a fairly high speed. A worn out battery,
partially discharged battery, and poor or loose cable connections will reduce cranking speed. Battery,
cables and connections should be cleaned and tightened regularly.

b) Fuel

For an engine to start and continue running, fuel must flow through the injection system. Unblended
#2 diesel fuel “clouds”, forming filter –clogging waste at temperature around +15° F (-10° C) making
starting and running impossible. Most engine manufactures recommend that fuel have a cloud point
at least 10° F (5° C) below the coldest anticipated temperature.

c) Lube Oil

Engine lubricating oil gets thicker at lower temperatures. Many oils that flow freely at 70º F (21º C)
are extremely thick at 0º F (-18º C). Follow your engine manufacturer’s recommendations regarding
oil viscosity for the coldest temperatures you expect your engine to encounter.

3) 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.

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

a) General

Pull all circuit breakers and/or disconnect battery negative terminal.
(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 (Factory Part No. 76A1354-001) 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 Section 2-2. 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. Be sure the solution is thoroughly mixed.
(4) Clean the exterior of the engine. Dry with clean rags and compressed air.
(5) Seal all engine openings. Use a waterproof, vapor proof material that is strong enough to resist

puncture damage from air pressures.

c) Long Time Storage (Over 30 Days)

To protect the generator and other electrical components, the complete unit should be packaged
using moisture proof packaging material and sealing material. Place containers of moisture
absorbing chemicals (Factory Part No. 76A-1354-001) in the unit before packaging. The unit may be
stored for long periods with no special preparation if it is possible to operate the engine once each
week. When starting once a week proceed as follows:

(1) Make certain the cooling system is adequately protected.

WARNING

ENSURE adequate ventilation before starting the engine.

(2) Start the engine and operate under full load until coolant temperature has reached at least 176ºF

(80ºC).

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

(3) While the engine is running, ensure that normal operating controls are in good working condition

before shutdown and storage. If weekly operation is not possible, contact the nearest engine

manufacturer distributor for instructions.

4) Preparation for Shipment

a) Disconnect battery negative terminal before shipping.
b) During long shipments, vibration, jolting, etc may loosen the generator set retaining hardware.

CAUTION

When shipping the unit, provide sufficient retaining materials to ensure the generator
set cannot roll out or off the vehicle in which it is being transported.

NOTE: It is suggested that strong banding be used to secure the generator set, or a strong steel bar
be either welded or bolted across the front of the generator set frame.

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60CU24 / Series 500060C / 400 Hz. Generator Set

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 or 28.5V DC power.

NOTE: Read ALL of the operating instructions before attempting to operate the equipment.

WARNING

Ear protection equipment may be necessary when working close to this equipment.

2) 400 Hz. Operating Procedure

a) Pre-start inspection

(1) Be sure the fuel shutoff valve on the unit is open.
(2) Ensure 12 VDC power is available to the engine starting system.
(3) Check the engine and generator compartments to make certain they are free of rags or other

foreign materials.
(4) Make certain there is sufficient lubricating oil and coolant in the engine.
(5) Check that all circuit breakers are reset.
(6) Make certain the “STARTER ENABLE/DISABLE” switch is enabled, and the “FREQUENCY

ADJUST” switch is disabled.

b) Normal Engine Starting Procedures

Engine starting procedures are outlined below. The engine’s operating controls and monitori ng
instruments are illustrated in Figure 1 and 2.

CAUTION

NOTE: The engine manufacturer’s operation manual is provided with this manual.

(1) If illumination is required, press “LAMPS” push-button switch one time. Pressing this button

switch also activates the fuel gage.
(2) On days when the ambient temperatures are below 60° F, press the “ENGINE HEATER” push-

button to engage the air intake heater prior to starting the engine. The light in the button will

illuminate when the intake heater is engaged (if the light does not illuminate, the engine is ready

to start) and will go off when the intake heater is disengaged, thus signifying the engine is ready

to start.

Refer to operating instructions in the engine manufacturer’s operation manual, when
starting engine for the first time.

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60CU24 / Series 500060C / 400 Hz. Generator Set

3 4

12

6 8 7,10 10,1110,12

5

139 10,15 10,1617

1. Fuel Gage (M13)

2. Front Panel

3. Engine Coolant Temperature Gauge (M24)

4. Running Time Meter (M4)

5. Oil Pressure Gage (M25)

6. Battery Voltmeter (M5)

7. Frequency Meter (M3)

8. Control Panel Label

9. Fault Code Meter (M6)

April 01, 2005 Chapter 1-3

10. Strip Lights (DS60-DS62) [Not Shown]

11. AC Generator Ammeter (M1)

12. AC Voltmeter (M2)

13. Adjustable Grip Latch

14. Control Panel Door Hinge [Not Shown]

15. DC Voltmeter [Optional with TR]

16. DC Ammeter [Optional with TR]

17. Front LED PC Board (A5) [Shown Opposite Side]

Control Panel Door

Figure 1

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

1. Meter Selector Switch (S3)

2. Test/Reset Switch (S77)

3. Engine Stop Switch (S76)

4. DC Starting Current Switch (S431) [Optional with TR]

5. DC Output Contactor Switch (S430) [Optional with TR]

Control Push-Button Switch Panel

Figure 2

1245678910 3

6. AC Output No. 2 (S275) [if applicable]

7. AC Output No. 1 (S75)

8. Engine Start Switch (S24)

9. Air Intake Heater Switch (S79)

10. Panel Light Switch (S74)

April 01, 2005 Chapter 1-3

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

CAUTION

Never use an ether start system in conjunction with the air intake heater.

(3) Press the green “ENGINE START” push-button switch and hold until engine starts. The engin e

will start at idle speed, and the green light in the “ENGINE START” push-button switch will flash

to indicate that power is available to the engine’s ECM circuit.

CAUTION

Do not attempt to bring to rated speed for at least 5 seconds after engine starts.
Damage to the starter and flywheel will result.

CAUTION

If the engine fails to start within 5 seconds, the control system will automatically
disable the starting motor and indicate a low oil pressure fault. The emergency stop
switch must be pressed to reset the control system and allow another starting attempt.
If the engine fails to start after four attempts, an inspection should be made to
determine the cause.

If the engine fires sufficiently to disengage the starter gear, but does not start, allow
the starting motor to come to a complete stop before attempting to engage the starter
again, then press the start push button switch.

(4) Check oil pressure to make certain that it is normal, and observe all other engine instruments for

normal operation.
(5) Allow engine to idle and warm for 3 - 5 minutes before bringing it up to rated speed.

CAUTION

To eliminate the possibility of wet stacking (See Appendix A), DO NOT allow the
engine to idle for long periods of time.

c) Failed Starting Procedure

In the event that the engine fails to start, the circuitry must be reset before the next attempt. To do
this:

(1) Push the red “EMERGENCY STOP/RESET BUTTON” on the control box door to the right of the

control panel.
(2) Pull the red “EMERGENCY STOP/RESET BUTTON” back out before the next attempt to start

the generator set.

d) AC Power Delivery

(1) Press “ENGINE START” push button switch a second time to bring engine from idle speed to

rated speed. The ECM will immediately increase engine speed to 2400 RPM and maintain it.

The voltage build-up will occur automatically. Also the green indicating light in the “ENGINE

START” push-button switch will glow continuously.

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

(2) Observe generator instruments. The frequency meter should indicate exactly 400 Hz. With the

“METER SELECT” push button switch set to read any line-to-neutral position, (A-N, B-N, or C-

N), the voltmeter should read 115 volts. With the “METER SELECT” push button switch set to

any line-to-line position, (A-B, B-C, or C-A), the voltmeter should read 200 volts.
(3) The final step in delivering power is closing one or both of the load contactors. When the

instruments indicate satisfactory frequency and voltage values, close either load contactor (or

both load contactors) by momentarily pressing the load contactor(s) (“OUTPUT NO. 1” or

“OUTPUT NO. 2”, if applicable) push button switch. The yellow or orange indicating light of the

push button switch that is pressed will glow continuously, indicating that the load contactor is

closed and power is available at the aircraft.
(4) Early in the power delivery run it is recommended that the operator check output voltage and

current in each of the three phases. Use the “METER SELECT” push button switch to select the

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

practice to observe the instruments until load conditions stabilize.

CAUTION

NEVER press the test/reset push button switch while power is being delivered.

The contactors will open and power to the aircraft will be suddenly interrupted.

(5) A condition of over-voltage, under-voltage, under-frequency, over-frequency, or overload in the

output circuit will automatically open the load contactor and display a fault code to signal the

operator which of the above faults caused the protective monitor system to operate. After the

fault has been corrected, press the “TEST/RESET” push-button switch to reset the protective

relay system. Proceed with power delivery by operating the load contactor push button switch.

WARNING

NEVER disconnect the output cable while power is being delivered. Output

contactors must be open prior to removal of the cable from the aircraft.

CAUTION

The generator set must be shut down so that the failed power delivery problems can
be diagnosed. Only licensed technicians should work on this generator set.

e) Failed AC Power Delivery

If the contactor indicating light should go out as soon as the push button switch is released, and a
fault code is displayed indicating that 28.5 VDC interlock signal is not being supplied from the aircraft
to the plug interlock relay, correct the condition and again press the load contactor(s) (“OUTPUT NO.
1” or “OUTPUT NO. 2”, if applicable) push button switch.

The “REGULATED/DIAGNOSTIC” switch (located on the VR1) must be set to “NORMAL” for power
delivery.

The “OUTPUT NO. 1” (or “OUTPUT NO. 2”, if applicable) “EF BY-PASS ON/OFF” switch (located
on the CTL) must be set to “ON” position.

See section 2-4 for other No. 1 (or No. 2, if applicable) Load Contactor Operating Circuit for additional
troubleshooting procedures.

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

f) Discontinue Power Delivery with Unit Shutdown

(1) Normal conditions

a Push the load contactor(s) (“OUTPUT NO. 1” or “OUTPUT NO. 2”, if applicable) push

button switch to open the contactor. The indicating light (yellow or orange depending on the
contactor used) on that switch will go OFF immediately to indicate that the load contactor has
opened and power is no longer being delivered to the aircraft. The engine will remain at
rated speed.

b Push the red “ENGINE STOP” push-button switch once to bring the engine down to idle

speed. This will begin the automatic shutdown sequence to shut off the engine, gauges,
lights, etc., after approximately 3 - 5 minutes.

c Disconnect output cable from aircraft after engine is at idle speed only.
(2) Emergency conditions

a Depress the “EMERGENCY STOP BUTTON” located on the control box door to the right of

the control panel. When pushed this button instantly shuts the generator set off and must be
pulled back out to reset itself for restarting the generator set.

CAUTION

Do not use the “EMERGENCY STOP BUTTON” button as a normal shutdown device.
Damage to the engine turbo charger may result without proper cooling time. Use the
“ENGINE STOP” push-button for all normal engine shutdowns.

3) DC Operating Procedure (Optional, See Appendix A)

The 28.5 VDC transformer-rectifier is an optional add-on to the GPU. See Appendix A for more details on
the operation of the transformer-rectifier.

April 01, 2005 Chapter 1-3

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

Chapter 2 Service and Troubleshooting

Section 1 Maintenance Inspection/Check

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 to components, or failure of the equipment.

WARNING

STOP operations at once if a serious or possibly dangerous fault is discovered.

2) Maintenance Schedule

a) General

A periodic maintenance schedule should be established and maintained. A suggested schedule is
provided in Figure 1 on the following pages. It may be modified, as required to meet varying
operating and environmental conditions. It is suggested that generator set and vehicle inspections be
coordinated as much as possible.

b) Maintenance Schedule Check Sheet

It is strongly recommended that the customer use a maintenance schedule check sheet such as the
one in engine manufacture’s operation manual. The check sheet will provide a record and serve as a
guide for establishment of a schedule to meet the customer’s maintenance requirements for his
specific operation.

c) Time Intervals

The schedule is based on both hours of operation and calendar intervals. These two intervals are not
necessarily the same. For example, in normal operation the oil change period, based on hours of
operation, will be reached long before the three months calendar period. The calendar period is
included to make certain services are performed regularly when the equipment is stored, or being
operated infrequently. Lubricating oil standing in engines that are stored, or used very little, may tend
to oxidize and may require changing although it is not dirty. Perform all services on whichever-comes­first basis.

d) Identification of Interval Periods

Each interval period is identified by a letter A, B, C, etc. For example, services under B schedule
should be performed at the end of each 250 hours of operation, or every three months, BR service is
performed during the BREAK IN period (first 50-150 hours) and AR service is performed AS
REQUIRED.

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

Hourly Interval

AR 50-150 10 250 500 1000 1500 2000

Calendar Interval Once Daily 3 Mo. 6 Mo. 1 Yr. 1.5 Yr. 2 Yr.
Symbol

AR BR A B C D E F

Engine

Change Air Cleaner Cartridge X
Check Coolant Hose and Clamps X
Check Crankcase Oil Level X
Drain Fuel PreFilter Elements X
Check Coolant Level X
Check for Leaks and Correct X X
Check Air Cleaner Indicator X
Check Exhaust System X
Change Lubricity Fuel Filter Element X X
Change Fuel Pre-Filter Element X X
Check Fuel Pump X
Check Radiator Core and Hoses X
Check Oil Pressure and Record X
Change Crankcase Oil X X
Change Oil Filter Element X X
Check Engine and Generator Mounts X X
Check Coolant, Additive-Concentration X X
Check Fan Hub and Drive Pulley X
Check Hose Clamps on Air Intake Side X
Check Belts Conditions and Tensioner X
Check and/or Adjust Valve Clearance X
Check Water Pump X X
Steam Clean Engine X X
Clean Fuel System X
Check Alternator X
Check Cranking Motor X
Check Vibration Damper X
Check Cooling system X

April 01, 2005 Chapter 2-1

Maintenance Schedule

Figure 1 (Sheet 1 of 2)

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

Hourly Interval

AR 50-150 10 250 500 1000 1500 2000

Calendar Interval Once Daily 3 Mo. 6 Mo. 1 Yr. 1.5 Yr. 2 Yr.
Symbol

AR BR A B C D E F

Engine (continued)

Flush and Change Coolant X
Check Fan Mounting Spring & Fall
Clean Cooling System Spring & Fall
Check Hoses Spring & Fall
Clean Electrical Connections Spring & Fall
Check Thermostats and Seals Fall

Electrical (12 VDC System)

Check All Lights X
Check Alternator Charging Rate X
Check Battery and Fluid Level X
Clean Battery Terminals X X
Check Wiring and Connections X
Check All Engine Meters X

Electrical (400-Hz System)

Check E-F By-Pass Operation X
Check Output Cable and Connectors X
Check Volt, Amp & Frequency Meters X
Check and/or Adjust Output Voltage X X
Inspect Wiring and Connectors X
Clean and Inspect Generally X

3) Inspection/Check

a) General

Inspections, checks, and maintenance are described in general and more specific and detail ed
information can be found in Section 2-2 and 2-3, when applicable.

April 01, 2005 Chapter 2-1

Maintenance Schedule

Figure 1 (Sheet 2 of 2)

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

b) “AR” Checks and Operations (As Required)

(1) Engine

a Change Air Cleaner

A definite time schedule for changing the air cleaner cannot be established. This filter should
not be washed more then six times or retained for more than one year of service, which ever
comes first.

b Check and tighten, as required, all coolant hose clamps, air intake hose clamps and exhaust

clamps. Check all coolant hoses, air intake hoses and exhaust pipes for leaks.

(2) Electrical System (12 VDC)

a Check Battery Terminals

Anytime the compartment doors are opened for any reason, visually check battery cable
connectors and battery posts. If corrosion is observed, disconnect cables and clean battery
posts and connectors with a wire brush or special battery post-cleaning tool. Coat posts and
connectors with a light film of petroleum lubricant before reconnecting cables.

(3) Electrical (400 Hz System)

a Check the output voltage and be sure it is set for 115 VAC ± 1 V. Adjustment can be made

using the fine adjustment located on the Voltage Regulator PC Board (REG).

c) “BR” Checks and Operations (Break-In Period, Once After 50-150 hrs.)

The following procedures are precautionary measures taken on most new engines. If a problem
occurs with any of the following issues be sure to recheck it after the next 50-150 hours.

(1) Engine

a Check for leaks and correct. This involves an overall inspection of the engine and may

require some maintenance if leaks are found. Refer to the engine manufacturer’s operations

manual for assistance.
b Change all fuel filter elements. Metal shavings from the new fuel tank can clog the filter.
c Change crankcase oil. New engines often release metal shavings more frequently. Therefore

the crankcase oil must be changed as a precautionary measure.
d Change oil filter element. The oil filter should be changed with the oil.
e Check engine and generator mounts to ensure they are properly installed and they have not

worked loose. (Torque is set at 122 N-m or 90 ft-lb. for generator and 136 N-m or 100 ft-lb.

for engine).
f Check coolant additive concentration. Refer to the engine manufacturer’s operations manual

for assistance.

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60CU24 / Series 500060C / 400 Hz. Generator Set

g Steam clean the engine to free it of oil and dirt to prevent uneven engine cooling “hot spots”.

The oil and dirt can also fall into the engine and fuel system when covers are removed during

repair work.
h Inspect the water pump weep hole for indication of a steady leak. If a steady flow of coolant

or oil is observed, replace the water pump with a new or rebuilt unit. Refer to the engine

manufacturer’s operations manual for assistance.

d) “A” Checks and Operations (10 Hours or Daily)

(1) Engine

a Check Crankcase Oil Level

CAUTION

CAUTION

DO NOT overfill. DO NOT operate the engine with oil level below the lower bar or

above the upper bar on the dipstick.

(i) Check oil level daily with oil gage dipstick.

(ii) Oil level should not be checked until 3 to 5 minutes after engine shutdown. Keep oil

level as near the upper bar as possible.

b Drain Fuel Pre-Filter Element

The life of the fuel pump and injectors can be extended if the operator drains about a cup of

fuel from the fuel pre-filter element to remove water and sediment before starting the engine

each day.

BE SURE to prime and bleed the fuel system after draining the filters, replacing filter
element, or if the fuel tank has run empty. Failure to do so can cause engine starting
problems.

(i) Provide a container for catching drained fuel.

(ii) Open the drain valve on the fuel/water filter by turning it counterclockwise.

(iii) Drain the filter until clear fuel is visible.

(iv) Tighten the drain valve.

(v) Safely dispose of drained fu el.

(vi) Purge air from fuel system if necessary.
c Check Coolant Level

Check coolant level daily or at each fuel fill interval. Investigate for cause of any coolant loss.

WARNING

Cooling system is pressurized. To avoid personal injury, DO NOT remove radiator
cap when engine is hot.

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

d Check for Leaks and Correct

At each daily start-up, check for coolant, fuel, and oil leaks. Coolant leaks may be more

noticeable when components are cold. Observe pumps, hoses, fittings, gasket conne ctions,

etc., for signs of leakage. Correct as required.

Fuel Drain

Fuel Filter and Drain

Figure 2

e Check Air Cleaner Indicator

At each daily start-up, observe the air cleaner indicator light. If this light comes ON, it

indicates that the air cleaner should be changed.
f Check Exhaust System

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

any gasket or joint leaks.

WARNING

A leaking and defective exhaust system could be a fire hazard.

(2) Electrical System (12 VDC)

a Check All Lights

Check all indicating lights to be sure they will operate when they should. If any light fails to

operate, check both the lamp and its protective circuit breaker. Figure 5 lists all lamps with

their location and part number. Figure 6 lists all circuit breakers.

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60CU24 / Series 500060C / 400 Hz. Generator Set

b Check Alternator Charging Rate

Observe the 12 VDC ammeter each time the engine is started. A zero amperage reading o r

extremely high reading for any length of time indicates trouble in the alternator, regulator,

battery, or interconnecting wiring.
c Check the operation of all the engine meters.

(3) Electrical (400 Hz System)

b Check Output Cables and Connector

Check the output cable plug connection for damaged insulation and contacts each time the

connector is detached from the aircraft.
b Monitoring Instruments

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

e) “B” Check and Operations (250 Hours or 3 Months)

(1) Engine

a Charge-Air-Cooler and Piping

Inspect the charge-air-cooler for dirt and debris blocking the fins. Check for cracks, holes, or

other damage.

Inspect the pipes and hoses for leaks, holes, cracks, or loose connections. Tighten the hose

clamps if necessary.
b Change oil and oil filters
c Check and record oil pressure

After each oil change, check and record oil pressure at idle speed after oil has warmed to

approximately 140º F. Record oil pressure under identical conditions at each oil change

interval. A comparison of pressure at idle speed with previous readings will give an indication

of progressive wear of oil pump, bearings, shafts, etc. Investigate any abnormal change in

pressure readings.
d Change all fuel filters.
e Check Radiator Core and Hoses

Inspect the radiator core for dirt and debris blocking the fins. Clean as necessary. Check for

cracks, holes, or other damage.
f Check Fuel Pump

Inspect the fuel injection pump mounting nuts for loose are damaged hardware.

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60CU24 / Series 500060C / 400 Hz. Generator Set

(2) Electrical (12 VDC system)

NOTE: The battery furnished with this generator set is MAINTENANCE FREE.
a Battery Electrolyte Level (if applicable)

Battery electrolyte level must be maintained above top of plates. Add distilled water as

required.

CAUTION

DO NOT overfill.

b Check Battery

If battery requires water frequently, or is low in charge, the reason for the condition must be

found and corrected.
c Check battery terminals and clean, if necessary.

(3) Electrical (400 Hz System)

a Check the operation of the E-F bypass system.

f) “C” Checks and Operations (500 Hours or 6 Months)

(1) Engine

a Check Engine and Generator Mounts

CAUTION

An unstable or loosely mounted engine can create hazardous environment and may
also damage equipment.

(i) Engine mount bolts must be torqued to 136 N-m (100 ft-lb.).

(ii) Generator mount bolts must be torqued to 122 N-m (90 ft-lb.).
b Check Coolant Additive Concentration

The cooling system protective liquid (nitrite-, amine- and phosphate free) provides effective

protection against corrosion, cavitation, and freezing. See engine manufacturer’s operation

manual for ordering and mixture details.

(2) Electrical (12 VDC system)

a Wiring

Inspect all cables and leads for worn or damaged insulation.

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60CU24 / Series 500060C / 400 Hz. Generator Set

b Connections

Inspect connectors for damaged or corroded condition.

(3) Electrical (400 Hz System)

a Protective Monitoring Circuits

Check operation of all protective monitoring circuits to make certain they will function if a fault

should occurs in the output circuit. Procedures for testing these circuits are contained in the

Adjustment/Test section of this manual.
b Inspect Wiring and Connections

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

connections for tightness.
c Clean and inspect generally

g) “D” Checks and Operations (1000 Hours or 1 Year)

(1) Engine

a Check Fan Hub and Drive Pulley

Inspect for loose bolts or worn features. Tighten bolts and replace parts if necessary. Refer

to the engine manufacturer’s operations and maintenance manual for assistance and the

most update to date information.
b Check Hose Clamps on Air Intake Side

Be sure that all clamps are properly secured to prevent leaks and all hose are in good

condition.
c Check Belt Condition and Tensioner

Refer to the engine manufacturer’s operations and maintenance manual for assistance and

the most update to date information.
d Check and/or Adjust Valve Clearance

Refer to the engine manufacturer’s operations and maintenance manual for assistance and

the most update to date information.
e Check Water Pump

Inspect the water pump weep hole for indication of a steady leak. If a steady flow of coolant

or oil is observed, replace the water pump with a new or rebuilt unit. Refer to the engine

manufacturer’s operations manual for assistance.

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h) “E” Checks and O perations (1500 Hours or 1.5 Year)

(1) Engine

a Steam Clean Engine

There are several reasons why the engine exterior should be kept clean. Dirt on the outside

will enter fuel and oil filter cases and rocker housings when covers are removed, unless dirt is

removed first. A clean engine will run cooler and develop fewer hot-spots. Steam cleaning is

one of the most satisfactory methods of cleaning and engine; however, there are some

CAUTIONS to be observed:

WARNING

Exercise care to avoid injury and damage to eyes and skin.

CAUTION

1. If a cleaning compound is used, select one that is free from acid and will not
remove paint.

2. Protect (or remove) all electrical accessories, such as voltage regulator, alternator,
and electrical wiring.

3. Seal all openings. DO NOT use a flammable solvent.

4. DO NOT use mineral spirits or solvents on a hot engine.

5. Remove or protect bottom panel of unit (belly pan) to protect insulation.

b Clean Fuel System

See engine manufacturer’s operation manual for instructions.
c Check Alternator and Cranking Motor.

The alternator and cranking motor on this particular engine require no periodic lubrication.

i) “F” Checks and Operations (2000 Hours or 2 Years)

(1) Engine

a Check Vibration Damper.

Check vibration damper for looseness, wobble, chunking and streakin g. Also verify the hub

bolts are tightened to the engine manufacturer’s specifications.

Refer to the engine manufacturer’s operations and maintenance manual for assistance and

the most update to date information.
b Check Charge-Air-Cooler and Radiator Systems

(i) Check for damaged hoses and loose or damaged hose clamps.

(ii) Check the radiator for leaks, damage, and build up of dirt in the fins. Clean or

replace as necessary.

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c Flush cooling sy stem and change coolant.

j) Seasonal Maintenance Checks Spring/Fall (Engine)

(1) Check Fan Mounting

a Check fan to be sure it is securely mounted.
b Check for fan wobble and/or broken/cracked blades.
c Check fan hub and crankshaft pulley for secure mounting.

3

1

4

1. Fan Pulley

2. Vibration Damper

Engine Accessories

(2) Check cooling system each spring and fall. Clean if necessary.
(3) Check All Hoses.

April 01, 2005 Chapter 2-1

3. Alternator

4. Belt Tensioner

Figure 3

2

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In addition to daily checks of hoses for leaks, inspect hoses thoroughly each time the cooling
system is cleaned and serviced.

Inspect for signs of deterioration and collapse. Inspect for cracks and cuts. Inspect for cutting
and deformation caused by hose clamps. Replace hoses as required.

(4) Check thermostat and seals each fall when cooling system is serviced.

k) Lamps Circuit breakers, and Fuses

(1) Check all lamps daily
(2) Check circuit breakers and fuses as required.
(3) The lamp chart lists all lamps with their location and identifying trade number in table below.
(4) The circuit breaker chart lists all circuit breakers with their location, size, and type.
(5) The fuse chart lists all fuses with their location, size, and type.

Item Protected Location Quantity Size

Engine Air Intake Heater Top of Inside Bulkhead 1 100 A
Load Contactor Circuit Voltage Regulator PCB 1 1 A
Voltage Regulator PCB Voltage Regulator PCB 1 1 A
Field Voltage Circuit Voltage Regulator PCB 1 5 A
Transformer-Rectifier [Optional] Transformer-Rectifier PCB 1 1 A

Fuse Identification Chart

Figure 4

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Light Identification Location

Instrument Panel Lights Switch Panel 67
Engine Start Indicator Switch Panel 1815
Engine Stop Indicator Switch Panel 1815
No. 1 Load Contactor Indicator Switch Panel 1815
No. 2 Load Contactor Indicator Switch Panel 1815
Test/Reset Indicator Switch Panel 1815
Pre-heater Indicator Switch Panel 1815
Clearance Lights (optional) Canopy Top 57
Engine Gauge Lights Inside Each Gauge 53

Lamp Identification Chart

Lamp (Bulb) as per Lamp

Industry Trade Number or

Description

Figure 5

Item Protected Location Quantity Size

Engine Circuit and Instrument Panel Inside Control Box 1 10 A
Controls Inside Control Box 1 5 A
Marker Lights Inside Control Box 1 10 A

Circuit Breaker Identification Chart

Figure 6

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Section 2 Maintenance Procedures

1) General

A suggested maintenance schedule was provided in Section 1 of this Servicing Chapter. Each step of the
schedule was also covered in general in Section 1. This Section covers maintenance in more detail,
where necessary.

WARNING

STOP operations at once if a serious or possibly dangerous fault is discovered.

2) Lubrication

a) General

Proper lubrication is one of the most important steps in good maintenance procedure. Proper
lubrication means the use of correct lubricants and adherence to a proper time sched ule. Lubrication
points, frequency of lubrication, and recommended lubricants are indicated in Figures 1 and 2.

b) AC Generator

The 400 Hz generator requires NO lubrication.

c) Generator Controls

Generator controls and instruments require no periodic lub rication.

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 en gine manufacturer’s
“Operation and Maintenance Manual” and incorporated here to make them more readily available to
operators and maintenance personnel.

(1) Lubrication schedule

Time schedules indicated on the Lubrication Chart, Figure 1, 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, high oil temperatures, or intermittent
operation. However, time intervals should not exceed those indicated in the chart without careful
evaluation.

(2) Oil specification

Engine lubricating oil, recommended by the engine manufacturer, is identified by an API
(American Petroleum Institute) classificat i on designation. The manufacturer does not
recommend any specific brand of lubricating oil.

The use of quality lubricating oil, combined with appropriate lubricating oil drain and filter change
intervals, are important factors in extending engine life.

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Oil recommended for the diesel engines in this application is API Class CCMC.
Lubricating oil is discussed in detail in the engine manufacturer’s operation manual.

(3) Oil viscosity

A temperature and oil viscosity index chart is shown below. For operation at temperatures
consistently below -13ºF (-25ºC), refer to the engine manufacturer’s operation manual.

(4) Changing engine oil

Oil should be changed once after the first 50 - 150 hrs. of use, then every 250 hrs of engine
operation thereafter. The generator set is equipped with an hour meter to record actual engine
operating time. The ideal time to change engine oil is soon after a power delivery run, when the
engine is at operating temperature.

Change the oil filter element each time the oil is changed.

NOTE: If lubricating oil is drained immediately after the unit has been run for some time, most of the
sediment will be in suspension and will drain readily.

CAUTION

High ash oils may produce harmful deposits on valves that can cause valve burning.

CAUTION

Do not use solvents as flushing oils in running engines.

Change oil as follows:
a Provide an open container for catching the old oil below the oil drain plug. Container capacity

must be greater than 20 quarts (19 liters).
b The oil drain tube can be attained though a hole in the access panel underneath the

generator set.
c Open drain plug located in oil pan.
d While oil is draining, change the oil filter element. See instructions below.

(i) Provide a container for catching spilled oil from the filter.

(ii) Remove the oil filter by twisting counter-clockwise and inspect it.

NOTE: The gasket can stick to the filter head. Make sure it is removed before installing a new filter.

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Item Maintenance Required

Check oil level daily or after every 10 hours of use. Change oil and the oil filter

Lube Oil

after the first 50 to 150 hours of use, then at 250 hour or 3 month intervals

thereafter. Use oil specification API CF-4, HT/HS Viscosity 3.7cP minimum.
Capacity 10 quarts (9.5 liters)
Oil Filter Replacement

Oil Filter Replacement-Equipment Manufacturer No. 286897-028

Oil Filter Replacement-Engine Manufacturer No. LF 3805

VISCOSITY AMBIENT TEMPERATURE CONDITIONS

Lube Oil Viscosity
Required as per
Ambient Temperatures

Synthetic Oils

Fuel Water Separator and
Lubricity Additive Filter

Coolant

Coolant hoses and
connections

Air Cleaner

SAE 15W40 (Preferred)

SAE 10W30

SAE 5W30

SAE 0W30

0ºF (-18ºC) and above for most climates

-10ºF to +50ºF (-23ºC to +10ºC) Winter conditions

-20ºF to +50ºF (-29ºC to +10ºC) Artic Conditions

-20ºF and below to +50ºF (-29ºC and Below to +10ºC)

See the engine manufacturer’s operations manual for usable synthetic oils and

instructions.

Drain filters daily. Change filter elements every 250 hours or after 3 months of

use, whichever comes first.

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

Section 2-2, paragraph 6. Engine coolant capacity (system): 38 quarts (36 liters)

Check coolant hoses and connections daily for leaks.

Change air cleaner filter as required when air cleaner indicator (on engine control

panel) shows that it should be changed.

Fan Belt Check fan belt condition and tension every 500 hours or 6 months of use.

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

Alternator Alternator bearings are sealed and require no periodic lubrication.

Starter Starter motor bearings are sealed and require no periodic lubrication.

Water Pump The water pump is packed at assembly and requires no periodic lubrication.

Fan Hub The fan hub is lubricated at assembly and requires no periodic lubrication.

April 01, 2005 Chapter 2-2

Lubrication and Maintenance Chart

Figure 1

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OM-2098C / Operation and Maintenance Manual
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Symbol Name Specification Notes

1 Grease, General Purpose MIL-G-3545 Excludes those of sodium or soda

soap thickness.

2 Oil, Engine, Heavy Duty API Class CC Must contain as but not more than

1.85%

3 Dry Graphite Lubricant (for

trailer brake cables)

MIL-T-5544, or

equivalent

Lubricants Chart

Figure 2

Use on brake cables. DO NOT use
general purpose grease.

CAUTION

CAUTION

If bearing metal particles are found on the element or in the shell, the source should
be determined before a failure.

Determine source of moisture, internal leaks, defective seals, gaskets, etc.

(iii) Fill the new filter with clean lubri cating oil before installation.
(i) Apply a light coating of lubricating oil to the gasket sealing surface and install the

filter. DO NOT over tighten the filter.

Oil Fill

Lubrication System

Figure 2

Oil Level Check

e Clean the drain plug and install when engine oil has completely drained. Torque the drain

plug to 44 foot-pound (60 Nm).

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f Use the oil refill tube to refill the crankcase with new, clean oil that meets engine

manufacturer’s recommendations.

NOTE: Using a funnel to fill the oil crankcase will help prevent spills.

Lubricating oil capacity (w/ filter) 10 quarts (9.5 liters)
Coolant capacity system 38 quarts (36 liters)

CAUTION

1. Always use clean containers, funnels, etc.

2. Don’t forget to close the drain plug valve, and install the new oil, before starting the
engine.

g Start engine and check oil pressure at once. Allow engine to idle for 5 minutes, check for

leaks, than stop the engine.

h After the engine has been stopped for about 5 minutes, recheck the oil level. Add oil, if

required, to bring the level up to the high bar on the oil dipstick.

e) Engine Accessories Lubrication

(1) Alternator

Most alternators contain sealed bearings and require no periodic lubrication, however, ch eck to
make certain there are no lubrication points on your particular alternator.

(2) Starter

Most starting motors are lubricated at assembly and should be re-lubricated only when the starter
is removed and disassembled, however, inspect the starter to make certain it has no lubrication
points.

(3) Water Pump

The water pump is packed at assembly and requires no periodic lubrication. Replace pump if
signs of lubricant leakage are found.

(4) Fan Pulley

The fan hub is also lubricated at assembly and requires no periodic lubrication. Replace hub if
lubricant is leaking.

3) Servicing the Air Cleaner

This air cleaner is a disposable type which, when dirty may be discarded. A definite time schedule for
cleaning or changing the air cleaner cannot be determined because of varying ope rating conditions. This
air cleaner filter can be removed from the air cleaner housing and replaced by unfastening the three metal
clamps on the end of the air cleaner housing. It may be inspected either at prescribed service intervals or
at any time deemed necessary.

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Service
Indicator

Air Cleaner

Air Cleaner Assembly

Figure 3

a) Inspecting the Air Cleaner

(1) Make periodic checks of air cleaner inlet screen for obstructions. If any obstructions are present,

remove them.

(2) Check outlet connection for proper seal.

b) Changing the Air Filter

(1) Unfasten the three metal clamps on the end of the air cleaner housing.
(2) Remove end cover of housing
(3) Pull out air filter element and replace.
(4) Replace end cover on housing, making certain that the filter is centered in the housing.
(5) Refasten the three metal clamps on the end of housing.

c) Disposal

Normal trash pick-up is should be acceptable. NEVER burn the air filter for disposal.

4) Engine Fuel

a) How to select Fuel—Quality

The quality of fuel oil used in the diesel engine is a major factor in engine performance and life. Fuel
oil must be clean, completely distilled, stable and non-corrosive.

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CAUTION

Due to the precise tolerances of diesel injection systems, it is extremely important that
the fuel be kept clean and free of dirt or water. Dirt or water in the system can cause
severe damage to both the injection pump and the injection nozzles.

CAUTION

The use of low lubricity fuels can shorten life and/or damage the engine’s fuel pump.
The engine manufacturer recommends only diesel fuel.

Use commercially available diesel fuel with less than 0.5% sulfur content. If the sulfur content is
higher than 0.5%, oil change intervals should be reduced (See engine manufacturer’s operation
manual).

In general, fuels meeting the properties of ASTM designation D 975 (grades 1-D and 2-D) have
provided satisfactory performance. For more information regarding the selection of fuel to use, refer
to publication “Engine Requirements—Lubricating Oil, Fuel, and Filters” available from authorized
engine manufacturer’s service outlets.

b) Cold Weather Operation

In cold weather, diesel fuel will form wax crystals, which can restrict flow and clog filters. Fuel oil
suppliers approach this problem several ways. Some provide a specially refined product, while
others may use flow-improving additives or winter blends. Winter blended fuel will likely contain
kerosene or 1-D fuel, which provide good cloud point temperatures, but result in a lighter fuel with a
lower heat content. These fuels may be used, but they may result in reduced engine power and/or
fuel consumption.

In most cases, adequate resistance to cold can be obtained by adding an additive. For further
assistance contact the nearest engine manufacturer’s service representative.

5) Engine Fuel System

The fuel system consists of five primary components: Fuel tank, Fuel Water Separator (Pre-Filter), Fuel
Lift Pump, Lubricity Additive Fuel Filter, and the Fuel Return Line. The following are maintenance
procedures for each of these items.

a) Fuel Tank

Be sure that no foreign objects are permitted in the fuel tank. The fuel tank must be removed and
flushed out if objects are found in the Fuel Water Separator

b) Fuel Water Separator

The equipment manufacturer has mounted a fuel water separator on the inner wall of the canopy. Its
function is to remove foreign material and extract water from the fuel before it enters the fuel lift
pump. Daily draining of the filter water separator bowl is required.

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(1) Draining the fuel water separator bowl.

a Open drain valve
b Drain accumulated water and contaminants.
c Close drain valve.

(2) Priming fuel water separator (when applicable).

a Loosen the vent plug.
b Pump until fuel purges at the vent plug.
c Close the vent plug, start the engine and check for lea ks,
d Correct as necessary with the engine off.

(3) Changing the fuel water/separator element (when applicable).

a The filter element replacement part number:

• Equipment Manufacturer Part No. 287639

• Racor Part No. R60P

b Drain off some fuel by loosening the vent plug and opening the drain valve.
c Spin the element and bowl off together. Remove the bowl and clean the O-ring gland.
d Apply a coating of clean fuel or motor oil to the new O-ring and element seal. Spin the bowl

onto the new element and the spin them both onto the filter head snugly by hand only. DO
NOT USE TOOLS TO TIGHTEN!

e With the vent plug still loosened, pump knob until fuel purges at the vent plug. Close the vent

plug, start the engine and check for leaks, correct as necessary with the engine off.

NOTE: The priming pump in the filter assembly is in tended for priming fuel into the Racor filter only
and not the entire fuel system.

c) Fuel Pump

The fuel pump supplies pressure to the fuel system so the diesel fuel can circulate freely. A
consistent check of the fuel pressure is necessary. Loss in fuel pressure in the fuel line may indicate
a faulty fuel pump.

d) Engine Lubricity Additive Fuel Filter

The forth item in the fuel line system is the factory installed lubricity additive fuel filter. The filter’s
function is to remove foreign material from the fuel and add a lubricity additive into the fuel before it
enters the engine’s fuel pump. The filament element is a throwaway type in which the case and
element are made as one disposable part.

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Fuel/Water Separator

Filter Drain

Fuel/Water Separator and Lubricity Fuel Filter

Figure 4

(1) Changing the lubricity fuel filter

a Replacement fuel filter part number:

• Equipment Manufacturer Part No. 286897-026

• Engine Manufacturer Part No. 3966659

b The fuel filter must be change after every 250 hours of operation in order for the fuel filter to

continue adding the proper amounts of the lubricity additive into the fuel system.
c Shut off fuel valve.
d Place a pan underneath the fuel filter to catch spilled fuel.
e Undo fuel filter with commercial tool and spin off.
f Catch any fuel.
g Clean any dirt from the filter carrier rim
h Apply a light film of oil or diesel on the rubber seal on the new filter.

CAUTION

When installing new element, do not over tighten it; mechanical tools may distort or
crack filter head.

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i Fill new filter with diesel fuel

Screw in the new fuel filter “snug”. Check that the cartridge is seated correctly against the

gasket and tighten with a final half turn.
j Open fuel valve.

e) Fuel Return

The fuel return is a fuel line (tube) that takes unused fuel from the engine, and delivers it to the fuel
tank. No maintenance is required.

f) Priming Fuel System (when applicable)

If this generator set has been run out of fuel, the fuel system must be manually primed with diesel fuel
up to the fuel water separator before the generator set can be started again. See Paragraph 5 for
instructions for priming the fuel water separator system. Once the fuel has reached the fuel water
separator, close all open valves (i.e. filter vent plug) and cranked the engine until the fuel reaches the
injectors and the engine starts.

CAUTION

Make sure that all rags, or absorbent sheets, are clear of moving engine parts and
cannot be drawn in to the radiator fan.

CAUTION

Do not crank the engine for more then 15 seconds continuously. Allow the starter to
cool for 15 seconds between attempts.

6) Engine Cooling System

a) General

Cooling system service requires more than maintaining the proper coolant level in the radiator and
protecting the system against freezing. Water should by clean and free of any corrosive chemicals
such as chloride, sulfate, and acids. It should be kept slightly alkaline with a pH value in the range of

8.0 to 9.5. Any water, which is suitable for drinking, can be used in the engine when properly treated
as described in engine manufacturer’s operation manual. The engine manufacturer’s representative
should be consulted regarding the selection of satisfactory brand, permanent-type antifreeze for use
in the cooling system.

b) Radiator Cap

(1) General

A pressure relief valve is built into the radiator cap. It is designed to open at a pressure of
approximately 10 psi (68.9 Kpa).

WARNING

When removing cap from a very hot radiator, do not turn cap past safety stop until the
pressure or steam has escaped.

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(2) Removal

To remove, turn the cap to the left (counterclockwise) to the safety stop. When all pressure is
released, press down on the cap and continue to turn until the cap is free to be removed.

CAUTION

Allow engine to cool before adding coolant.

CAUTION

Do not attempt to repair the valve in a radiator cap in case of failure. Replace with a
new cap.

(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) Coolant

The preparation and maintenance of the coolant solution is important to engine life and is completely
covered in the engine manufacturer’s operation manual. For information regarding coolant
specifications, testing equipment, antifreeze, etc., refer to engine manufacturer’s operation manual
that accompanies the equipment manufacturer’s manual or consult the local engine manufacturer’s
representative.

CAUTION

Never use soluble oil in the cooling system.

(1) General

A permanent type antifreeze is recommended for use in the cooling system.

CAUTION

1. DO NOT use methanol or alcohol as antifreeze.

2. DO NOT mix brands or type of antifreeze. A solution containing two or more types
of antifreeze is impossible to test accurately.

(2) Selecting antifreeze

a Select a permanent type antifreeze known to be satisfactory for use with chromate corrosion

resistor.
b When it is not known if the antifreeze is satisfactory for use with chromate resistor, check with

local engine manufacturer’s representative for a list of compatible antifreezes.

(3) Checking antifreeze solution

Check the solution with a reliable tester when in doubt about antifreeze protection.

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d) Draining the Cooling System

To completely empty the cooling system requires draining the engine block (if furnished) and the
radiator assembly. Both of the drain valves (radiator and block drain), can be opened/closed at the
same time but they do not need to be.

To drain the cooling system, proceed as follows:
(1) Remove radiator cap.
(2) Place a drain pan with at least a 40 quarts (28.4 liters) capacity under radiator to catch coolant.
(3) Place the radiator drain hose that comes off the two radiator drain valves, into the drain pans.
(4) Open the radiator drain valves.
(5) Allow the system to drain completely.
NOTE: Be sure the drain valves do not clog during draining.
(6) When the system is completely drained, close the drain valves and replace engine drain plug.

e) Flushing the Cooling System

Flushing the cooling system should be a yearly maintenance procedure. By flushing the system,
clean water is forced through the engine block to remove expired coolant and other contaminants.

f) Cleaning the Radiator Core

Blow out accumulated dirt from the radiator core air passages, using water. Bent or clogged radiator
fins often cause engine overheating. When straightening bent fins, be careful not to damage the
tubes or to break the bond between fins and tubes.

NOTE: Direct the water in a reverse direction to normal air flow. Normal flow on this installation is
from the engine compartment out ward.

g) Filling the Cooling System

The preparation and monitoring of coolant in liquid-cooled engines is especially important because
corrosion, cavitation, and freezing can lead to engine damage. For coolant system protection details
see the engine manufacturer’s operations manual.

(1) Install coolant

a Remove radiator cap. Be sure that both radiator drain valves are closed.
b Pour coolant into radiator very slowly until it reaches the bottom of fill neck. Allow time for

trapped air to escape from the system then continue filling until the coolant level remains at

the bottom of the fill neck.
c Start the engine and bring up to rated speed and allow the thermostat to open. Add coolant

as trapped air escapes from the system and the coolant level falls.

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d Continue to check coolant level until all trapped air escapes. Add coolant if needed to fill to

the bottom of fill neck. Install radiator cap.

(2) Inspection/Check

a Check system for evidence of leaks.
b Inspect all hoses. Install new hoses as necessary. Tighten hose clamps as required.
c Check the condition of fan and water pump belts. Replace belts if necessary.

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

h) Thermostat

The thermostat should be checked each fall, or as required. Refer to engine manufacturer’s
operations manual for recommended instructions.

7) Generator Maintenance

The 400 Hz generator requires no maintenance or service other than periodic cleaning. The unit is
brushless and has bearings that are permanently lubricat ed 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 not recommended because the use of steam and harsh
chemical compounds may result in damage to insulation and other generator components.

CAUTION

Do not use a flammable solvent. Be sure the unit is completely dry before operating.

b) Adjustment

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

8) Drive Belt

a) General

The engine cooling fan, alternator, and water pumps are driven by one serpentine belt, which must be
replaced if worn or damaged.

b) Preparation for Belt Check and Adjustment

All driven assemblies must be securely mounted in operating position before checking belt tension.

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c) Checking Belt Tension

CAUTION

Checking the tension and changing the serpentine belt should only be performed with
the engine off.

Check belt tension every 1000 hours, or once year, whichever comes first. A belt that is too tight is
destructive to bearings of the driven part. A loose belt will slip and cause inefficient operation of the
part being driven as well as wear to the belt.

CAUTION

Inspect and replace the belt if it has unacceptable cracks, is frayed, or has pieces of
material missing.

Belt tension may be checked by hand. To do so, manually depress the belt with an index finger to
determine the amount of belt deflection obtained. When a force is applied at a point halfway between
pulleys on the longest span of a belt, there should be no more than 1/2 inch of deflection attained.

Refer to the engine manufacturer’s operation manual for checking belt tension an d changing worn
belts.

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Section 3 Adjustment/Test

1) General

These adjustments and test procedures are applicable to testing and adjusting the generator set after
major repair, major parts replacements, or overhaul.

IMPORTANT

In order to perform most of the following test, a load bank with an EF interlock circuit
is required. But if no EF interlock is available on a load bank, see special procedure
in the EF Bypass section for testing the EF circuit.

2) Testing the 400 Hz. Generator Set

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 high bar on the dipstick.
(3) Check radiator coolant level (See 2-2, Paragraph 6).
(4) Check tension of drive belt (See 2-2, Paragraph 8).
(5) Inspect for oil, fuel and coolant leaks.
(6) If the setting of the output voltage coarse adjustment potentiometer (Figure 8) on the voltage

regulator has been disturbed, set it at center position (halfway between full clockwise position and
full counterclockwise position).

(7) Check control panel lights circuit breaker (Figure 2) by pressing panel “LAMPS” push button

switch (Figure 2). If panel lights operate, the circuit breaker, switch, and lamps are good.

(8) Check fault indication lights by pressing “TEST/RESET” push button switch (Figure 2). If fault

code display lights up, the control circuit breaker (Figure 3) is good.

(9) Make a general inspection of all wiring, and terminals. Inspect the equipment to be certain no

damage will result from starting the engine.

b) Operational Test Procedures

(1) Start the engine in accordance with instructions in Section 1-3, Paragraph 2.
(2) Check operation of engine instruments; ammeter, coolant temperature indi cator, oil pressure

gage and hour meter (all shown in Figure 1).

(3) Check engine idle speed. Should be 1000 +/- 25 RPM.
NOTE: A stroboscope may be required for this check.
(4) Again check for oil, fuel, and coolant leaks and correct any leaking condition.

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

3 4

12

6 8 7,10 10,1110,12

5

139 10,15 10,1617

1. Fuel Gage (M13)

2. Front Panel

3. Engine Coolant Temperature Gauge (M24)

4. Running Time Meter (M4)

5. Oil Pressure Gage (M25)

6. Battery Voltmeter (M5)

7. Frequency Meter (M3)

8. Control Panel Label

9. Fault Code Meter (M6)

April 01, 2005 Chapter 2-3

10. Strip Lights (DS60-DS62) [Not Shown]

11. AC Generator Ammeter (M1)

12. AC Voltmeter (M2)

13. Adjustable Grip Latch

14. Control Panel Door Hinge [Not Shown]

15. DC Voltmeter [Optional with TR]

16. DC Ammeter [Optional with TR]

17. Front LED PC Board (A5) [Shown Opposite Side]

Control Panel Door

Figure 1

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

1. Meter Selector Switch (S3)

2. Test/Reset Switch (S77)

3. Engine Stop Switch (S76)

4. DC Starting Current Switch (S431) [Optional with TR]

5. DC Output Contactor Switch (S430) [Optional with TR]

Control Push-Button Switch Panel

Figure 2

1245678910 3

6. AC Output No. 2 (S275) [if applicable]

7. AC Output No. 1 (S75)

8. Engine Start Switch (S24)

9. Air Intake Heater Switch (S79)

10. Panel Light Switch (S74)

April 01, 2005 Chapter 2-3

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

1

2

4

5

7 6

89

10

1. Engine Specific PC Board [ESB] (A1)

2. Engine Interface PC Board [EIB] (A2)

3. Digital Control PC Board [CTL] (A3)

4. Voltage Regulator PC Board [REG] (A4)

5. Transformer-Rectifier PC Board [TRB] (A404) {Optional}

3

6. +5, -12 VDC Power Supply (PS1)

7. Circuit Breaker Support Bracket

8. Marker Lights Circuit Breaker, 10 A (CB1)

9. Engine Circuit Breaker, 10 A (CB4)

10. Controls Circuit Breaker, 5 A (CB7)

April 01, 2005 Chapter 2-3

Control Box Interior Components

Figure 3

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

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

a Place regulated-diagnostic switch (Figure 8) in “REGULATED” position.
b Place EF Bypass switches (Figure 4) in “BYPASS / OFF” position.
c If the output voltage coarse adjustment potentiometer (Figure 8 ) on the voltage regulator has

been disturbed, place the knob at mid-range position.

(6) Bring the engine up to rated speed, which also energize the generator, by pressing the “ENGINE

START” push button switch (Figure 2) a second time. If the engine comes up to rated speed and
a 115 V voltage value appears on the voltmeter (Figure 1), the engine ECM and excitation circuits
are functioning.

(7) After generator overhaul or repair, the Regulated/Diagnostic switch (Figure 8) must be placed in

the “DIAGNOSTIC” position for 3 to 5 seconds to re-magnetize the exciter. Then return the switch
to the “REGULATED“ position after voltage has built-up.

(8) Observe frequency meter (Figure 1). If engine speed is properly set, frequency should read 400

Hz.

(9) Observe voltmeter (Figure 1). Use output fine voltage coarse adjustment potentiometer (Figure 8)

to adjust voltage to 115 V AC.

(10) Check adjustable voltage range.

a Observe voltmeter (Figure 1) and turn output voltage coarse adjustment potentiometer

(Figure 8) to full clockwise position. Maximum voltage should be 134 volts or higher.

NOTE: If voltage should decrease when regulator potentiometer is turned clockwise, it indicates that
internal wiring in the voltage regulator is incorrect. Replace complete voltage regulator as sembly.

b Observe voltmeter and turn regulator potentiometer knob to full counterclockwise position.

The minimum voltage should be 95 volts or lower.

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

c) Testing the No. 1 Output Circuit

(1) Place EF Bypass switch (Figure 4) in “BYPASS / OFF” position turn the EF signal “ON” on the

load bank. Then press the yellow No. 1 load contactor push button switch (Figure 2) to close
contactor, which is indicated when its internal indicating light glows.

(2) Place EF switch on the load bank in the off position. The No. 1 load contactor should open

immediately, and the indicating light within the push button switch should go off. The fault code
display should also read “EF 1”, indicating an EF warning. This is because the interlock circuit of
the control PC board is not receiving 28.5 VDC signal from an outside source. It indicates that
the No. 1 interlock circuit is OPEN, as it should be when the interlock circuit is not receiving a 28
VDC signal. Reset the fault by pressing the “TEST/RESET” push button (Figure 2).

April 01, 2005 Chapter 2-3

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

PC Board Software

EF1 Bypass

EF2 Bypass, if appli c able

Service Tool Connect or

Digital Control PC Board

Figure 4

(3) Verify that when the EF Bypass switch (Figure 4) is in the “BYPASS / ON” position or the

“BYPASS / OFF” position, that the appropriate LED indication on the control panel display (Figure

5) is correct.

(4) Place EF bypass switch (Figure 4) in “BYPASS / ON” position. Press the No. 1 load contactor

push button switch. The No. 1 contactor power indicating light within the push button switch
should glow and remain on when the push button switch is released. This indicates that EF
bypass switch is functioning correctly. The corresponding LED (Figure 5) should also indicate the
bypass mode.

(5) Place the No. 1 EF bypass switch to “BYPASS / OFF” position. The No. 1 load contactor should

open at once and the yellow indicating light within the No. 1 load contactor push button switch
should go off and the fault code display should also read “EF 1”, indicating a EF warning. The
corresponding LED (Figure 5) should also indicate the EF present mode. Reset the fault by
pressing the “TEST/RESET” push button (Figure 2).

(6) Proceed to step 12.

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

(Steps 7 - 11 are only required if EF interlock system is not available on a load bank.)

(7) Connect a source of 24 V-DC power (two twelve-volt batteries connected in series) to terminals

N, F (or E) at the output terminal panel. Connection polarity is important. Connect plus (+) to
terminals E or F, and minus (-) to terminal N.

(8) Verify that when the EF Bypass switch (Figure 4) is in the “BYPASS / ON” position or the

“BYPASS / OFF” position, that the appropriate LED indication on the control panel display
(Figure 5) is correct during the following steps 9 and 10.

(9) Place the No. 1 EF bypass switch to “BYPASS / OFF” position. Press the No. 1 contactor

operating push button switch (Figure 2). The No. 1 contactor power on indicating light, within the
push button switch, should glow and remain on when the push button switch is released. This
indicates that the load contactor is closed and the plug interlock circuit is functioning properly.

(10) Disconnect the 24 V-DC power source and the No. 1 load contactor should open immediately,

and the indicating light within the push button switch should go OFF. The fault code display
should also read “EF 1”, indicating an EF warning. This is because the interlock circuit of the
control PC board is not receiving 28.5 VDC signal from an outside source. It indicates that the
No. 1 interlock circuit is OPEN, as it should be when the interlock circuit is not receiving a 28 VDC
signal. Reset the fault by pressing the “TEST/RESET” push button (Figure 2).

EF Bypass Indication

Figure 5

EF Bypass Indication

(11) In EF bypass mode, 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.

(12) Increase load at the load bank to full load.
(13) Check operation of the engine ECM by observing the frequency meter (Figure 1) when generator

is switched from no load to full load, and vice versa. Use the No. 1 contactor control push button
switch to apply and remove load several times. Steady-state frequency droop should be no more
than 1 Hz.

(14) Follow instructions in Paragraph 3 to set voltage regulator line drop compensation for the length

and size of cable being used.

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

(15) Check voltage regulator, at intervals, from no load to full load. Observe and note voltage at

various loads. Steady-state voltages should vary no more than +/- 1% from normal output
voltage.

(16) Operate the No. 1 output circuit of the unit no less than 10 minutes under full load. The overload

protection MUST NOT trip.

(17) Operate the No. 1 output circuit of the unit at 125% load (325 amperes) for 5 minutes immediately

following the full load run. The overload device MUST trip within 5 minutes, and the fault code
display should read “70.18” indicating an overload condition in “OUTPUT NO 1” (Reference fault
chart in Section 2-4).

(18) Reset the fault by pressing “TEST/RESET” push button (Figure 2).

d) Testing the No. 2 output circuit (if applicable)

(1) Repeat steps (1) through (18) in the previous section “Testing the No. 1 Output Circuit” for

testing the No. 2 output circuit.

e) Testing and checking meters, switches, protective monitoring circuits, and fault code display

(1) Check accuracy of AC voltmeter

a Open door of control box and connect a master voltmeter of known accuracy to terminals of

the AC voltmeter (Figure 1).
b Compare the unit’s voltmeter reading with master meter. Error must not exceed 2% of full

scale.

(2) Check accuracy of AC ammeter

a Connect a master ammeter of known accuracy to the AC ammeter (Figure 1).
b Compare the unit’s ammeter reading with master meter under various loads. Error must not

exceed 4% of full scale.

(3) Check operation of the “METER SELECT” switch (Figure 2).

a In any LINE-TO-NEUTRAL position, the voltmeter reading should be 115 volts when the LED

under the voltmeter indicates one of the 3 phase being check (Figure 5).
b In any LINE-TO-LINE position, voltmeter reading should be 200 volts when the LED under

the voltmeter indicates two of the phases being checked (Figure 5).

(4) Check accuracy of frequency meter

a Connect a master frequency meter of known accuracy to the terminals of the frequency meter

(Figure 1).
b Compare meter readings. Error must not exceed 1% of full scale.

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

NOTE: Make all protective system tests with the unit operating under a load for the following steps.
Reference Chapter 2, Section 4, for all fault codes.

(5) Check operation of over-voltage circuit and fault code display.

a With the unit running at a normal load, adjust the coarse adjustment potentiometer (Figure 8)

on the voltage regulator clockwise to increase voltage until the over-voltage sensing circuit

actuates the protective monitor. After the protective monitor is activated, the load contactor

will open and the fault code display will display fault “70.16”. At 125 volts, the circuit will trip

after a 1-second time delay. At higher values of voltage, time delays for over voltage trips are

as follow:

• At 140 volts, the circuit will trip within 160 milliseconds.

• At 180 volts, the circuit will trip within 50 milliseconds.

b If the load contactor does not open under the conditions described in step (a), refer to the

Troubleshooting Chart in Section 2-4.
c Return unit to normal operating conditions by adju sting coarse a djustment potentiometer

(turning it counterclockwise) and pressing “TEST/RESET” button switch to clear the fault

code (Figure 2).

(6) Check operation of under-voltage circuit and fault code display.

With the unit running at a normal load, adjust the coarse adjustment potentiometer (Figure 8) on
the voltage regulator counterclockwise to decrease voltage until the under-voltage sensing circuit
actuates the protective monitor. After the protective monitor is activated, the load contactor will
open and the fault code display will display fault “70.17”. Follow the following steps below to
activate the under-voltage protective monitor. A stopwatch is required for this check.

a With the unit running at normal load, use the output voltage coarse adjustment potentiometer

on the voltage regulator to reduce the voltage to 104 volts. The load contactor should NOT

open.
b Reduce voltage in increments of 1 volt, with a time delay of 7 seconds between steps. At a

setting of 100 volts, the load contactor will open and the under voltage light will glow after a 7-

second time delay.
c If the load contactor does not open under the conditions described, refer to the

Troubleshooting Chart in Section 2-4.
d If the under voltage circuit performs satisfactorily, return unit to normal operation by adjusting

output voltage coarse adjustment potentiometer for normal output voltage, pressing the

“TEST/REST” push button switch to clear the fault code.

(7) Check under-frequency circuit and fault code display.

At some frequency value 380 Hz or less, after 7 seconds, the frequency condition should signal
the under-frequency circuit protective monitor to OPEN the load contactor and display “70.23” on
fault code display. To check the under-frequency protective components, proceed as follows:

April 01, 2005 Chapter 2-3

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

a While the unit is operating normally under load, set the frequency adjust switch (Figure 6) to

“TEST”. Use the frequency adjust potentiometer (Figure 6) to adjust frequency to 400 HZ.
b Reduce frequency in steps of 1 Hz, with a time delay of 7 seconds between steps.
c If the protective circuit opens the load contactor and displays fault “70.23” on the fault code

display after 7 seconds, at 380 Hz or less, all components of the system are functioning

properly.
d If the load contactor is not opened at 380 Hz or less after 7 seconds, refer to Troubleshooting

Chart in Chapter 2, Section 4.
e Return unit to normal operating condition by setting the frequency adjust switch to

“NORMAL” and pressing “TEST/RESET” button switch (Figure 2) to clear fault code.

Engine Codes

Frequency Adjustment Switch

Engine StopCheck Engine

PC Board Software

Frequency Adjust Potentiometer

Engine Specific PC Board

Figure 6

(8) Check over-frequency circuit and fault code display.

At some frequency value 420 Hz to 440 Hz, after 5 seconds, the over frequency sensing circuit
should signal the over-frequency circuit protective monitor to OPEN the load contactor and
display “70.22” on fault code display.

At any frequency value exceeding 440 Hz, the over-frequency circuit should immediately signal
the protective monitor to OPEN the load contactor and display “70.22” on fault code display..

To check the under frequency protective components, proceed as follows:
a While the unit is operating normally under load, set the frequency adjust switch (Figure 6) to

“TEST”. Use the frequency adjust potentiometer (Figure 6) to adjust frequency to 400 HZ.
b Increase frequency in steps of 1 Hz, with a time delay of 5-7 seconds between steps.

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

c If the protective circuit opens the load contactor and displays fault “70.22” on the fault code

after 5 seconds at 426 Hz, all components of the system are functioning properly.
d If the load contactor is not opened at 426 Hz after 5 seconds, refer to Troubleshooting Chart

in Chapter 2, Section 4.
e Return unit to normal operating condition by setting the frequency adjust switch to

“NORMAL” and pressing “TEST/RESET” button switch (Figure 2) to clear fault code.

NOTE: If the generator is operating under load at this point, open the contactors. There will be no
further need for the load bank in the following checks.

f) Testing for engine ECM faults

(1) Set the starter enable/disable switch (Figure 7) to “DISABLE”. “DISABLE” will prevent the

engine from starting, but will still supplying 12 VDC to the control system, while checking the ECM
faults.

(2) Press the green “ENGINE START” push button switch (Figure 2). Although the engine is not

running, the green light in the “ENGINE START” switch (Figure 2) will flash to indicate that power
is available to the engine ECM.

Starter Disable/Enable

PC Board Software

April 01, 2005 Chapter 2-3

Engine Interface PC Board

Figure 7

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

(3) If no active codes are recorded, both the “Engine Stop” (Figure 6) and “Check Engine” (Figure 6)

lamps will come on and stay on.
If active codes are recorded, both lamps will come on momentarily, then begin to flash one code

of the recorded faults.

(4) The fault code will flash in the following sequence:

First, a “Check Engine” (yellow) lamp will flash. There will be a short 1- or 2-second pause after
which the number of the recorded fault code will flash in the “Engine Stop” (red) lamp. There will
be a 1- or 2-second pause between each number. When the number has finished flashing in the
red lamp, the yellow lamp will appear again. The fault code will repeat in the same sequence.

The lamps flash each fault code 3 times before advancing to the next code. To skip to the next
fault code, move the Engine Codes Switch (Figure 6) momentarily to the UP position. You can go
back to the previous fault code by momentarily moving the Engine Codes Switch to the DOWN
position. If only one fault is recorded, the QSB control system will continuously display the same
fault code when the Engine Codes Switch is moved to either the UP or DOWN position.

(5) See engine manufacture’s manual for code meanings.

g) Re-checking the entir e unit after testing

(1) With the engine running at normal rated speed, check the entire unit for vibration and for any

parts that may have become loosened during the above checks. Tighten any loose hardware as
required.

(2) Check engine oil pressure at rated speed (2000 RPM). The oil pressure gage should indi cate at

least 44.9 psi (3.1 bar) when engine is hot. Also at rated speed, check the engine coolant
temperature. The temperature gage should indicate in the range of 180° to 190° F (82º to 88º C),
depending upon operating conditions.

WARNING

If a metal sounding rod is used to detect bearing noises, exercise extreme care to
avoid injury from moving components.

(3) Check 400 Hz generator bearings. Use a stethoscope or metal sounding rod to listen for unusual

noises. If using a metal rod, place on 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. Contact the equipment
manufacturer if in doubt of bearing serviceability.

3) Generator Set Adjustment

a) Generator Adjustment

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

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

b) Adjust 400 Hz voltage regulator.

When a voltage regulator is first put into service, or when output (generator-to-aircraft) cables are
changed, the regulator may require adjustments of output voltage value and line-drop compensation.
For making these adjustments, the voltage regulator has three potentiometers:

• A coarse output voltage potentiometer (Figure 8).

• A fine output voltage potentiometer (Figure 8)

• A line-drop compensation potentiometer (Figure 8).

For the following adjustment, the generator set must be running at rated speed (2000 RPM), unde r
no-load conditions. Adjust the regulator as follows:

Regulated/Diagnostic

PC Board Software

Voltage Adjustment, Coarse

Voltage Adjustment, Fine LDC Control

April 01, 2005 Chapter 2-3

Voltage Regulator PC Board

Figure 8

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

(1) Output Voltage Adjustment

a Adjust Voltage Control

The output voltage, at which the generator is regulated, is adjustable by the fine voltage

adjustment potentiometer (Figure 8). Turn the potentiometer adjustment clockwise to

increase generator output voltage, and counterclockwise to decrease voltage.

Observe the output voltage as indicated by the voltmeter, located on the control panel of the

generator set. Set output voltage at 115-V AC line-to-neutral (200-V AC line-to-line).
b Adjust Line Drop Compensation

Adjustment of line drop compensation is made with the line drop compensation potentiometer

(Figure 8). Turning the potentiometer knob clockwise increases the magnitude of the

compensation, and turning the potentiometer knob counterclockwise decreases the

magnitude (A graduated nameplate for specified cable lengths is included for quick

reference.). To adjust the line drop compensation, proceed as follows:

• Connect the generator set output cables to a load. Load the generator set with the
largest available three-phase load of rated power factor not exceeding the maximum
rating of the generator set.

• Measure output voltage at the load end of the cables. If the load voltage rises or drops
more than 1% at the load end of the cables, decrease or increase the line drop
compensation until the regulation is flat (115-V AC line-to-neutral and 200-V AC line-to­line).

• If the line drop compensation adjustments have affected the no-load voltage output,
adjust the fine output voltage control potentiometer to the desired value.

(2) Test the Voltage Regulator

After necessary adjustments have been completed, re-test the voltage regulator as follows:
a Connect a voltmeter at the load end of the generator output cables.

b Operate the generator set at no-load and observe voltage reading.
c Operate the generator set under load and observe voltage reading.
d Voltage under load and no load should vary no more than 1% at the load end of the cables.

c) Basic Engine Adjustments

Adjustment procedures applicable to the diesel engine are included in the engine manufacturer’s
operation manual, which is referenced in Chapter 5. Specific information for these engines is listed in
Figure 2. Refer to the engine operation manual for detailed information on the following engine
adjustments.

(1) Exhaust valve adjustment
(2) Fuel injector timing adjustment
(3) Engine idle speed adjustment

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

Engine idle speed is programmed at the factory. If adjustment is required, contact the local

engine distributor. The recommended idle speed is 1000 RPM, +/- 25 RPM.
NOTE: A stroboscope is required for engine idle speed checks.
(4) Engine speed limiting adjustment

The speed limiting adjustment is also set and sealed at the factory. Speed should be limited to

approximately 2750 RPM. If adjustment is required, contact your local engine distributor.

d) Engine Accessories Adjustment

(1) Alternator and fan belt adjustment

Refer to Section 2-1 and engine manufacturer’s manual.

Manufacturer Cummins Engine Company
Model No. QSB4.5
Type In-Line 4 cylinder, 4 cycle diesel, electronic controlled
Horsepower 110 hp (82 kW)
Idle speed 1000 ± 50 rpm
High speed limiting 2750 ± 75 rpm
Normal governed speed 2400 rpm
Lubricating oil capacity (w/ filter) 10 quarts (9.5 liters)
Coolant capacity system 38 quarts (36 liters)

ENGINE

Specifications and Capabilities

Figure 9

4) Generator and Exciter Test

The generator fields and exciter stator may be tested with a Kelvin bridge. This is a double-bridge type
instrument required for the very low resistance’s encountered in this test. It is understood that zero (0)
resistance indicates a SHORT CIRCUITED condition. An infinite resistance reading indicates an OPEN
CIRCUITED condition. See Figure 10 for resistance values.

a) Disconnect generator stator leads at the output module panel.
b) Disconnect the two black exciter field leads from terminal block mounted on output module panel.
c) Check resistance and compare to values given in Figure 5.

April 01, 2005 Chapter 2-3

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

Test Connection Resistance (Ohms)

Generator Stator Phase A to N (G1)* 0.00235
Generator Stator Phase B to N (G1)* 0.00235
Generator Stator Phase C to N (G1)* 0.00235
Exciter Stator Field (L2) 26.5
A - B, B - C, C - A Exciter Armature (G2) 0.1
Generator Revolving Field (L1) 2.1

*NOTE: The two leads of a phase must be connected when test is made. Take readings when unit
is cold and in an ambient temperature of 70 ºF (21ºC.).

Generator and Exciter Test Readings

Figure 10

5) 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 are as follows:

a) Disconnect exciter windings from 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.

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 connection 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 oppo site way, the diode may be considered
good.

6) Testing the Transformer-Rectifier (Optional, See Appendix A)

The 28.5 VDC transformer-rectifier is an optional add-on to the GPU. See Appendix A for more details on
the adjustment and test of the transformer-rectifier.

April 01, 2005 Chapter 2-3

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

Section 4 Troubleshooting Procedures

1) General

The Troubleshooting Chart (See Appendix A for the 28.5 VDC Transformer-Rectifier troubleshooting
information.) and Fault Code Chart, located in this section, covers the common faults and malfunctions
that you may find during operation or maintenance of this equipment. The charts may not list all faults
and malfunctions that may occur. If a fault of malfunction is not listed in the chart, start looking for the
cause at the source of power in the affected circuit. Refer to the schematic and connection diagrams in
Chapter 5. Test the circuit, step by step, until the source of the malfunction is isolated.

The Fault Code Chart is arranged under 2 headings: Commands and Faults. Commands display the
operation mode at the time a fault code is triggered.

The Troubleshooting Chart is arranged under 3 headings: Trouble Symptom and Condition, Probabl e
Cause, and Test Check and/or Remedy. Trouble(s), Symptom(s), and Condition(s) are described and
numbered. Probable Cause(s) are indented to the right and listed in numbered steps below Probable
Cause. Test Check and/or Remedy provides instructions for correcting the malfunction, and is listed
below each Test or Inspection procedure. Tests and inspections called for in the Troubleshooting Chart
are to be performed as described in Chapter 2, Section 1-3, of this manual.

2) Equipment for Troubleshooting

WARNING

CAUTION

A good quality multi-scale voltmeter is the only instrument required for troubleshooting. At least two
jumper leads with alligator, or similar clips, will be required. The engine electrical system may be
used as a 12 VDC power source.

Exercise extreme care to avoid contact with high voltage leads and components.
High voltage can kill!

Maintenance personnel must be very careful when performing terminal-to-termin al
checks to be certain the proper terminals are being used, especially when using
jumper leads. Damage to electrical components may result from the application of
improper voltage and current.

3) Parts Replacement

To lessen end item down time, and to get a faulty machine back on line as quickly as possible, the black
box concept of parts replacement is reflected in the Troubleshooting and Fault Code Chart. For example,
if a component on a control box PC board is defective, the quickest way to remedy the situation is to
replace the complete PC board and send the old to stock. Some of the assemblies that tend to lend
themselves to this concept are:

• Voltage regulator PC Board (REG)

• Control PC board (CTL)

• Engine Specific PC Board (ESB)

• Enigne Interface PC Board (EIB)

• 28.5 VDC Transformer-Rectifier PC Board (TRB) [Optional, See Appendix A]

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OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set

4) 400 Hz. Test Values

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

Generator output voltage at maximum voltage regulator potentiometer setting: 134 volts or higher.
Generator output voltage at minimum voltage regulator potentiometer setting: 108 volts or lower.
Over voltage relay Trips at 126 volts after a 1-second time delay.

Trips at 140 volts in 160 milliseconds.
Trips at 180 volts in 50 milliseconds.

Under voltage relay Trips at 100 volts after 7 seconds.

Trips at any value between 426-Hz and 480-Hz

Over frequency relay

Under frequency relay Trips at 375 Hz or less after a 5-second time delay.

after a 5-second time delay. Trips immediately at
any frequency exceeding 480-Hz.

Overload time delay

Frequency at rated speed of 2400 RPM is 400 +/- 2 Hz at no load and rated load.
Engine oil pressure (warm and at rated speed 2400 RPM) 45 to 90 PSI (445 to 621 kPa).
Engine coolant temperature (normal operation) 160 to 200º F (71 to 93º C).

Trips in approximately 5 minutes at 125% load of
GPU rating or at 60 kVA on either output.

5) 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.

6) Engine Troubleshooting

The ability of the engine to start and run properly depends upon a number of things.
a) An adequate supply of 12 VDC power reaching a good starter and starter button

b) An adequate supply of air, compressed to a sufficiently high pressure.
c) The injection of the correct amount of clean fuel at the proper time

NOTE: When trouble shooting the engine, keep these requirements in mind.

7) Illustrations

Illustrations, Figures 1, 2, 3 and 4, are referred to throughout the Troubleshooting Chart

8) Connection and Schematic Diagrams

All connection and schematic diagrams for generator, engine, lights, and all controls are located in
Chapter 5.

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9) GPU Control Monitoring

The GPU control system performs complete diagnostic testing and continuous monitoring of all critical
circuits and operating electrical values. If the control system senses a problem with one of the circuits or
if any of the electrical values exceeds its safe operating limit, the control system will shut the GPU down,
or may allow the GPU to continue operation depending on the severity of the condition.

a) Commands

The ongoing operations conducted by the GPU are driven by the list of commands in Table 1. The
control PC board communicates these commands to all of the PC boards in the GPU. The first half of
the fault code identifies the command that was present when the fault occurred.

Commands

01.
\

39.

40. Engine Start Mode

50. Engine Idle Mode

Self-Test Mode

70. Engine Run Mode

80. Engine Shutdown Mode

90. Engine Stop Mode

99. System Off Mode

Operating Commands

Table 1

(1) Self-Test Mode

When power is first applied to the control circuit, the GPU performs complete self diagnostics of
the internal circuitry. During this self test, the GPU will perform the commands listed in the
enclosed charts. When a fault is detected during the self test, the current “COMMAND” and
detected “FAULT” are displayed on the fault code display.

(2) Engine Start Mode

When the “ENGINE START” push-button is activated, the engine’s starter and the engine’s ECM
will be energized.

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(3) Engine Idle Mode

When the engine has been started, the engine will begin in the idle mode. The “ENGINE
START” push-button will flash indicating the engine is in the idle mode.

(4) Engine Run Mode

After the engine has been warmed up properly in the Engine Idle Mode, pressing the “ENGINE
START” push-button again will bring the GPU up to rated speed. The “ENGINE START” push­button light will no longer flash, but instead become continuously illuminated. The GPU is now
ready for aircraft loading.

(5) Engine Shutdown Mode

When shutting the GPU down, pressing the “ENGINE STOP” push-button will start the 3-5
minutes delayed shutdown period. The “ENGINE STOP” push-button will flashed and the engine
will return to idle speed. The shutdown period is required to sufficiently cool the engine’s
turbocharger.

(6) Engine Stop Mode

After the 3-5 minutes delayed shutdown period, the engine will stop running.

(7) System Off Mode

The power will be removed from the GPU’s entire control system.

b) Faults

Faults result when any of the fault limits are exceeded, when an internal problem occurs, or under
certain conditions that would cause injury to personnel or damage to an aircraft or the GPU. Faults
are also stored in memory as event records. The fault limits and conditions are preset at the factory.

Faults

.01

\

Warning (no operation changes)
.09
.10

\

Run Mode (minor fault)
.39
.40

\

Idle Mode (moderate fault)
.59
.60

\

Stop Mode (major fault)
.79
.80

\

Special Configuration (reserved)
.99

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Fault Codes

Table 2

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(1) Warning

Warning faults are faults that occur and have no effect on the operation of the GPU. An example
would be an intake air restriction fault due to a dirty filter. Although the GPU will continue to
operate, the fault will appear on the fault code display. Pressing the “TEST/RESET” push button
or shutting down the GPU will reset the fault.

(2) Run Mode

Run mode faults that occur will remove power form the aircraft but will not change the operating
speed of the engine. An example would be an over voltage fault. Although the contactors will
open and remove power from the aircraft, the engine will remain at rated speed, and the fault will
appear on the fault code display, along with the appropriate command. Pressing the
“TEST/RESET” push button or shutting down the GPU will reset the fault.

(3) Idle Mode

Idle mode faults that occur will remove power form the aircraft and drop the operating speed of
the engine to the idle setting. A possible example (depending on customer configuration) would
be a high temperature fault. The contactors will open and remove power from the aircraft, the
engine will drop to its idle speed, and the fault will appear on the fault code display, along with the
appropriate command. Pressing the “TEST/RESET” push button or shutting down the GPU will
reset the fault.

(4) Stop Mode

Stop mode faults that occur will remove power form the aircraft and shut the engine down. An
example would be a low oil pressure fault. The contactors will open and remove power from the
aircraft, the engine will shut down, and the fault will appear on the fault code display, along with
the appropriate command. Pressing the “TEST/RESET” push button or shutting down the GPU
will reset the fault.

(5) Special Configuration

These fault codes are reserved for special customer configurations. Contact the factory for
information.

c) Fault Code Display

The numbers that appear in the “FAULT CODE” display are used for troubl eshooting the GPU. To
read the four-digit fault code properly, it must be understood that the first two digits represent one half
of the fault code and the last two digits represent the other half.

• The first two digits on the left side of the Fault Code represent the Command.

• The two digits on the right side of the Fault Code represent the Fault Condition.

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Command Fault

70.67

Fault Codes

Fault Meter Display

d) Operation Monitoring

While applying power to an aircraft, the GPU continually monitors all critical circuits and operating
electrical values.

Figure 1

During 400 Hz AC and 28.5 VDC (if supplied) operation, the GPU continually performs Command
“70” (Engine Run Mode). When a fault is detected during operation, this Command and the detected
Fault are indicated in the “FAULT CODE” display.

By referencing the Command and Fault Code chart, the GPU state and exact fault can be
determined. When the fault is reset, and the GPU restarted, the GPU may often detect the fault again
revealing additional information. This method yields a high degree of troubleshooting accuracy.

Fault meter display example shown above: If the engine shuts down with the above fault code,
“70.67”, the engine ceases operation due to high coolant temperatures in the engine. The “70”
represents the command the GPU was executing at the time of the fault and shutdown (Command
“70” indicates an Engine Run Mode command.). The “67” represents the fault code that indicates the
action taken by the control system upon faulting (Fault “67” indicates a Stop Mode fault which shuts
the GPU down.).

e) Extracting Fault Code Information

In the event the GPU fault code history information is required for troubleshooting, all fault codes
stored in the control system’s memory (i.e. data records) can be extracted and viewed on the Fault
Meter Display (starting with the last fault code and scrolling backward through all previous fault
codes). The following are the procedures for extracting the fault code information:

(1) Pull the “EMERGENCY STOP” button out.
(2) Press the “LAMPS” push button to turn on the control box lights.
(3) Press the “TEST/RESET” push button and hold for 2 to 3 seconds until the data record number

appears on the display (See Figure 1A).

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