Hobart GPU-600 Operation And Maintenance Manual
OM-2010
121585
Revised 121691
031893
OPERATION AND MAINTENANCE
MANUAL
with
ILLUSTRATED PARTS LIST
for
GPU-600
SOLID STATE TRANSFORMER-RECTIFIER
RATED OUTPUT: 28 V-DC, 600 A
SPECIFICATION INPUT VOLTAGE FREQUENCY MODEL NUMBER
S6883-1 208/230/460 V, 3-PHASE 60-Hz 6T28-600CL
S6883-2 220/380 V, 3-PHASE 50-Hz 5T28-600CL
S6883A-1 208/230/460 V, 3-PHASE 60-Hz 6T28-600CL
S6883A-2 220/380 V, 3-PHASE 50-Hz 5T28-600CL
S6883A-3 230/460/575 V, 3-PHASE 60-Hz 6T28-600CL
Manufactured by
HOBART BROTHERS COMPANY
POWER SYSTEMS GROUP
GROUND POWER EQUIPMENT
TROY, OHIO 45373
U.S.A.
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SAFETY INSTRUCTIONS AND WARNINGS FOR ELECTRICAL POWER EQUIPMENT
WARNING
ELECTRIC SHOCK can KILL. Do not touch live electrical parts.
ELECTRIC ARC FLASH can injure eyes, burn skin, cause equipment damage, and ignite combustible
material. DO NOT use power cables to break load and prevent tools from causing short circuits.
IMPROPER PHASE CONNECTION, PARALLELING, OR USE can damage this and attached
equipment.
Important:- Protect all operating personnel. Read, understand, and follow all instructions in
the Operating/Instruction Manual before installing, operating, or servicing the equipment. Keep the
manual available for future use by all operators.
A. GENERAL
Equipment that supplies electrical power can cause serious injury or death, or damage to other equipment
or property. The operator must strictly observe all safety rules and take precautionary actions. Safe practices
have been developed from past experience in the use of power source equipment. While certain practices below apply only to electrically-powered equipment, other practices apply to engine-driven equipment, and
some practices to both.
B. SHOCK PREVENTION
Bare conductors, or terminals in the output circuit, or ungrounded, electrically-live equipment can fatally
shock a person. Have a certified electrician verify that the equipment is adequately grounded and learn what
terminals and parts are electrically HOT. Avoid hot spots on machine. Use proper safety clothing, procedures, and test equipment.
The electrical resistance of the body is decreased when wet, permitting dangerous currents to flow
through it. When inspecting or servicing equipment, do not work in damp areas. Stand on a dry rubber mat
or dry wood, use insulating gloves when dampness or sweat cannot be avoided. Keep clothing dry, and
never work alone
1. Installation and Grounding of Electrically Powered Equipment
Equipment driven by electric motors (rather than by diesel or gasoline engines) must be installed and
maintained in accordance with the National Electrical Code, ANSI/NFPA 70, or other applicable codes. A
power disconnect switch or circuit breaker must be located at the equipment. Check the nameplate for voltage, frequency, and phase requirements. If only 3-phase power is available, connect any single-phase rated
equipment to only two wires of the 3-phase line. DO NOT CONNECT the equipment grounding conductor
(lead) to the third live wire of the 3-phase line, as this makes the equipment frame electrically HOT, which can
cause a fatal shock.
Always connect the grounding lead, if supplied in a power line cable, to the grounded switch box or building ground. If not provided, use a separate grounding lead. Ensure that the current (amperage) capacity of
the grounding lead will be adequate for the worst fault current situation. Refer to the National Electrical Code
ANSI/NFPA 70 for details. Do not remove plug ground prongs. Use correctly mating receptacles.
2. Output Cables and Terminals
Inspect cables frequently for damage to the insulation and the connectors. Replace or repair cracked or
worn cables immediately. Do not overload cables. Do not touch output terminal while equipment is energized.
3. Service and Maintenance
This equipment must be maintained in good electrical and mechanical condition to avoid hazards stemming from disrepair. Report any equipment defect or safety hazard to the supervisor and discontinue use of
the equipment until its safety has been assured. Repairs should be made by qualified personnel only.
Before inspecting or servicing electrically-powered equipment, take the following precautions:
a. Shut OFF all power at the disconnecting switch or line breaker before inspecting or servicing the
equipment.
b. Lock switch OPEN (or remove line fuses) so that power cannot be turned on accidentally.
c. Disconnect power to equipment if it is out of service.
d. If troubleshooting must be done with the unit energized, have another person present who is trained in
turning off the equipment and providing or calling for first aid.
C . FIRE AND EXPLOSION PREVENTION
Fire and explosion are caused by electrical short circuits, combustible material near engine exhaust pip-
ing, misuse of batteries and fuel, or unsafe operating or fueling conditions.
1. 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.
2. 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.
3. Engine Fuel
Use only approved fuel container or fueling system. Fires and explosions can occur if the fuel tank is not
grounded prior to or during fuel transfer. Shut unit DOWN before removing fuel tank cap. DO NOT completely fill tank, because heat from the equipment may cause fuel expansion overflow. Remove all spilled
fuel IMMEDIATELY, including any that penetrates the unit. After clean-up, open equipment doors and blow
fumes away with compressed air.
D. 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.
E. BODILY INJURY PREVENTION
Serious injury can result from contact with fans inside some equipment. Shut DOWN such equipment for
inspection and routine maintenance. When equipment is in operation, use extreme care in doing necessary
trouble-shooting and adjustment. Do not remove guards while equipment is operating.
F. MEDICAL AND FIRST AID TREATMENT
First aid facilities and a qualified first aid person should be available for each shift for immediate treat-
ment 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-tomouth. If no detectable pulse, begin external heart massage. CALL EMERGENCY RESCUE SQUAD IMMEDIATELY.
G. EQUIPMENT PRECAUTIONARY LABELS
Inspect all precautionary labels on the equipment monthly. Order and inspect all labels that cannot be
easily read.
OM-2010
Table of Contents
SUBJECT CHAPTER/SECTION PAGE
WARNING
LIST OF EFFECTIVE PAGES
INTRODUCTION
CHAPTER 1. RECEIPT OF EQUIPMENT AND
INSTALLATION
SECTION 1. RECEIPT OF EQUIPMENT 1-1 1
SECTION 2. INSTALLATION 1-2 1
A. Location 1-2 1
B. Internal Wiring check 1-2 1
C. Connecting the Machine to Line Voltage 1-2 1
D. Grounding 1-2 2
E. Output Leads 1-2 3
F. Lub rication 1-2 3
CHAPTER 2. DESCRIPTION AND OPERATION
SECTION 1. DESCRIPTION 2-1 1
1. General 2-1 1
2. Special Features 2-1 3
3. Detailed Description 2-1 5
A. General 2-1 5
B. Main Transformer 2-1 5
C. Control Transformer 2-1 8
D. Auxiliary Power Circuitry 2-1 8
E. Output Contactor Circuitry 2-1 8
F. Output Filter Circuitry 2-1 9
G. Front Panel Control Components 2-1 9
(1) Output Meter 2-1 9
(2) Input Contactor Switch with Light 2-1 9
(3) Output Contactor Switch and Light 2-1 9
(4) Overload Trip Light 2-1 10
H.Main SCR Heat Sink Assembly 2-1 10
J. Solid State Printed Circuit Control Board 2-1 10
April 10/89 Revised Table of Contents
Page 1
OM-2010
SUBJECT CHAPTER/SECTION PAGE
(1) Electronic Overvoltage/Overload Trip Circuit 2-1 10
(2) Electronically Controlled Current Limit 2-1 10
(3) Regulated DC Output Voltage 2-1 10
(4) Thermal Overload Trip 2-1 11
SECTION 2. OPERATION 2-2 1
1. General 2-2 1
2. Preparation for Operation 2-2 1
3. Operation Procedure 2-2 2
A. Input Control Functions 2-2 2
B. Output Control Functions 2-2 2
C. Voltmeter 2-2 2
D. Output Current Limit 2-2 2
CHAPTER 3. SERVICING
SECTION 1. MAINTENANCE 3-1 1
1. General 3-1 1
2. Inspection 3-1 1
3. Lubrication 3-1 1
4. Parts Replacement 3-1 2
A. Minor electrical components 3-1 2
B. Major Electrical Components 3-1 2]
Section 2. INSPECTION CHECK
AND REPAIR 3-2 1
1. General 3-2 1
2. Exterior Cables and Connections 3-2 1
A. Input and Output Cables 3-2 1
B. Cable Connections 3-2 1
3. Controls and Instruments 3-2 1
A. Voltmeter, Ammeter and Control Switches 3-2 1
B. Indicating Lights 3-2 1
(1) Power input and output lights 3-2 1
(2) Overload trip indicating light 3-2 2
C. Overload Thermostat 3-2 2
D. Starting Current Limit Potentiometer 3-2 2
E. Contactors 3-2 4
(1) Output Contactor, K2 3-2 4
(2) Input Contactor, K1 3-2 4
F. Control Transformer 3-2 4
4. Major Components Check and Repair 3-2 4
A. Main Power Transformer 3-2 4
B. Silicon Controlled Rectifier Assembly and
Flyback Diode 3-2 5
Table of Contents April 10/89 Revised
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OM-2010
SUBJECT CHAPTER/SECTION PAGE
(1) Visual 3-2 5
(2) Voltohmmeter 3-2 5
(3) Voltage Test for SCR Assembly 3-2 6
C. Filter Choke and Capacitor Voltage Test 3-2 6
D. Printed Circuit Control Board 3-2 6
SECTION 3. CALIBRATION AND TEST
OF PC CONTROL BOARD 3-3 1
1. General 3-3 1
2. Printed Circuit Board Test Values and
Adjustments 3-3 1
SECTION 4. TROUBLESHOOTING 3-4 1
1. General 3-4 1
2. Troubleshooting 3-4 1
3. Equipment for Troubleshooting 3-4 2
4. Safety 3-4 2
5. Voltages of Interest 3-4 2
6. SCR Malfunction Instructions 3-4 3
A. Normal SCR Malfunction Conditions 3-4 3
B. Severe SCR Malfunction Conditions 3-4 3
C. SCR tests or checks 3-4 3
CHAPTER 4. ILLUSTRATED PARTS LIST
SECTION 1. INTRODUCTION 4-1 1
1. General 4-1 1
2. Purpose 4-1 1
3. Arrangement 4-1 1
4. Explanation of Parts List 4-1 1
A. Contents 4-1 1
B. Parts List Form 4-1 2
(1) “FIGURE-ITEM NO.” Column 4-1 2
(2) “HOBART PART NUMBER” Column 4-1 2
(3) “NOMENCLATURE” Column 4-1 2
(4) “EFF” (Effective) Column 4-1 2
(5) “UNITS PER ASSEMBLY” Column 4-1 2
SECTION 2. MANUFACTURER’S
CODES 4-2 1
1. Explanation of Manufacturer’s (Vendor)
Code List 4-2 1
April 10/89 Revised Table of Contents
Page 3
OM-2010
SUBJECT CHAPTER/SECTION PAGE
SECTION 3. PARTS LIST 4-3 1
1. Explanation of Parts List Arrangement 4-3 1
2. Symbols and abbreviations 4-3 1
SECTION 4. NUMERICAL INDEX 4-4 1
1. Explanation of Numerical Index 4-4 1
CHAPTER 5. OPTIONAL EQUIPMENT
CHAPTER 6. MANUFACTURER’S LITERATURE
UNUSUAL SERVICE CONDITIONS
Table of Contents April 10/89 Revised
Page 4
LIST OF EFFECTIVE PAGES
CHAPTER/ CHAPTER/
SECTION PAGE DATE SECTION PAGE DATE
List of 3-2 4 Apr 10/89
Effective 3-2 5 Apr 10/89
Pages 1/2 Apr 10/89 3-2 6 Apr 10/89
3-2 7 Apr 10/89
Introduction 1 Apr 10/89 3-2 8 Apr 10/89
Introduction 2 Apr 10/89
Introduction 3 Apr 10/89 3-3 1 Apr 10/89
Introduction 4 Apr 10/89 3-3 2 Apr 10/89
3-3 3 Apr 10/89
Contents 1 Apr 10/89 3-3 4 Apr 10/89
Contents 2 Apr 10/89 3-3 5 Apr 10/89
Contents 3 Apr 10/89 3-3 6 Apr 10/89
Contents 4 Apr 10/89 3-4 1 Apr 10/89
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1-1 2 Apr 10/89 3-4 3 Apr 10/89
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2-1 11 Apr 10/89 4-2 2 Apr 10/89
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OM-2010
April 10/89 Revised List of Effective Pages
Page 1
OM-2010
LIST OF EFFECTIVE PAGES
CHAPTER/
SECTION PAGE DATE
4-4 1 Apr 10/89
4-4 2 Apr 10/89
4-4 3 Apr 10/89
4-4 4 Apr 10/89
5-0 1 Apr 10/89
5-0 2 Apr 10/89
List of Effective Pages April 10/89 Revised
Page 2
INTRODUCTION
1. General
This Introduction is intended to give the reader a better understanding of how to use the manual properly.
The manual can be very helpful to you if you will READ THIS INTRODUCTION FIRST. READ AND UN-
DERSTAND THE MANUAL BEFORE ATTEMPTING TO OPERATE, INSTALL, OR REPAIR THIS
EQUIPMENT.
2. Scope
The manual covers a solid state controlled transformer-rectifier, 600 A DC ground power unit having the
Specification Numbers listed. It gives a detailed description of the equipment and includes information covering operation, installation, troubleshooting and repair.
3. Purpose
OM-2010
The manual’s purpose is to provide information and instructions to experienced operators, electricians,
and repairmen who have never seen or operated this equipment. It is the intent of the manual to guide
and assist operators and maintenance personnel in the proper use and maintenance of the equipment.
4. Contents
Immediately following the Introduction is a List of Effective Pages which lists each page in the manual by
its Chapter/Section, and page number. Directly opposite each page number listing is a date which indicates whether the page is original or revised.
A complete Table of Contents appears next in sequence. It contains a list of all Chapters, Sections, and
the principal paragraph titles within each Section. The location of each listing is identified by Chapter/Section and page number. A complete list of illustrations with their location is located at the end of the Table
of Contents.
The main text of the manual is divided into five Chapters as follows:
Chapter 1. Receiptand Installation Instructions
Chapter 2. Description and Operation
Chapter 3. Servicing
Chapter 4. Illustrated Parts List with Index
Chapter 5. Optional Equipment
Chapter 6. Manufacturer’s Literature
Each Chapter is divided into as many Sections as necessary. Sections are always referred to by a combination Chapter/Section number. Example, 2-3 refers to Chapter 2, Section 3.
April 10/89 Revised Introduction
Page 1
OM-2010
5. Format
A. Paragraphing and Outlining
The material within each Section is divided into main subjects with applicable paragraph headings
and sub-headings as required. This method not only helps keep information closely knit, but provides
a means of identifying material for reference purposes. For example, a portion of the Description Section might logically follow this arrangement and paragraphing:
1. Control A. Interior Panel
(1) Protective devices
(a) Overload relay
(2) Contactors
B. Page Numbering
Page numbers do not run consecutively throughout the manual. Each page is identified by the Chapter/Section number in which it appears, and by a page number within the Chapter/Section. Therefore,
the first page in each Section is page 1. These identifying numbers appear in the lower, outside corner of each page. Each page also bears a date located in the corner opposite the page number. This
date is either that of original issue, or of the latest revision. Any revision to the original text is identified
by a heavy black line in the left-hand margin. Illustrations follow a numbering system similar to page
numbering. The first Figure in each Section is Figure 1.
6. How to Use the Manual
A. General
This manual follows the format, rules and style proposed by, and generally accepted by members of
the Air Transport Association. Insofar as possible, information is grouped to help the user locate it
quickly. All tables, charts, diagrams, etc., as well as illustrations, are identified by Figure Number
Fig. 2)
B.How to Locate Information
Even if you have read the manual completely and thoroughly, the easiest and quickest way to locate
information is by using the Table of Contents. Look for new and added information at the end of the
section in which it is normally found.
(1) Table of Contents
to avoid confusion.
The complete Table of Contents is relatively short. Even if the user has no idea where a certain
bit of information is located, the general location can be quickly found by running through the Table of Contents. For example, some adjustment information is needed. A quick look at the Table
of Contents indicates that Adjustment/Test information is located in 3-3
(i.e.,
(Chapter 3, Section 3).
Introduction April 10/89 Revised
Page 2
(2) List of Illustrations
A complete list of Illustrations follows the Table of Contents and includes the title, figure number,
and Chapter/Section, with page number location of all illustrations contained in the manual. Locate the appropriate title in the List of Illustrations, then turn to the Chapter/Section and page
number indicated. A complete set of electrical schematic and connection diagrams is included in
Chapter 5.
(3) References
To avoid repetition and lengthy explanations, references to other material are used throughout
the manual. Both material in the text and illustrations may be referred to in order to clarify or expand information and instructions. Portions of the text are referred to by identifying the paragraph
in which referenced material may be found. A reference to other material would be in order here
by referring to paragraphing information contained in paragraph 5, A above. When referenced material is located in the same Chapter/Section as the reference, only the paragraph identification is
given.
Example:
OM-2010
(Ref. Para. 1, A)
means the material is to be found in paragraph 1, A, of the same Chap-
ter/Section.
When referenced material is located in another Chapter/Section, both the Chapter/Section
number and the paragraph identification are given.
Example:
(Ref. 1-2, Para. 1, A)
means that the referenced material is located in Chapter/Section 1-2,
and identified by paragraph 1, A.
Components shown in illustrations and illustrations themselves are referenced in a similar manner. When this type reference is made, the item number of the part and the Figure number in
which it appears are given.
Example:
(Ref. 2, Fig. 3)
refers to item number 2 which appears in illustration Figure 3 of the same
Chapter/Section.
When the referenced Figure appears in another Chapter/Section, the reference will include the
Chapter/Section number.
April 10/89 Revised Introduction
Page 3
OM-2010
Example:
(Ref. 2-3; 1, Fig. 4)
4.
Once a Figure number reference has been established for a series of instructional steps, the Figure number is not repeated. Only the item numbers of parts involved are referenced.
For example, an instruction might appear like this: “Loosen screw
(4),
tor
When an item is referenced without a figure number, it will always apply to the last preceding
Figure number mentioned in the text.
and remove brush
tells the user to refer to Chapter/Section 2-3, and to see item 1, in Figure
(2, Fig. 6),
slide out connec-
(6)”.
NOTE 1: The word Seemay appearin some references,as (SeeFig. 2). It means exactlythe samething
as Ref., however, its usage seems a little more direct and definite.
NOTE 2: When an “output cable” is mentioned in the manual, it refers to a large cable used to carry
output current. A special connector for the two output leads and the ground lead may be required when
delivering power directly to an aircraft.
7. SERVICE
If you have any questions concerning your Hobart Power Systems Division equipment, please contact
our Service Department by mail, telephone or FAX.
Write: Hobart Brothers Company
Power Systems Group
Service Department
Troy, Ohio 45373
U.S.A.
Call: Area Code (513) 339-5060
FAX: 513-339-4219
Introduction April 10/89 Revised
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OM-2010
CHAPTER 1. RECEIPT OF EQUIPMENT
AND INSTALLATION
SECTION 1. RECEIPT OF EQUIPMENT
Check the equipment received against the Hobart Brothers Company invoice to make certain that the
shipment is complete and undamaged. If the equipment has been damaged in transit, notify the carrier
(railroad, trucking company, etc.)
damage claim, furnish Hobart Brothers Company with full information about the claim. If the shipment is in
error, contact Order Department, Hobart Brothers Company, Power Systems Division, Troy, Ohio 45373.
Give the MODEL, SPECIFICATION, and SERIAL numbers of the equipment, and a full description of the
parts in error. Refer to the title of this manual for a listing of the specification numbers this manual describes.
An identification and rating nameplate is normally located on the power supply front panel for your
convenience. If the rated input or output voltages do not agree with your requirements, contact the order
department for instructions or corrective action.
Generally, it is good practice to move the equipment to the site of installation before uncrating or unpacking .
Take care to avoid damage to the equipment if bars, hammers, etc., are used. Lifting eyes which extend
through the top of the cabinet have been provided to facilitate handling with a crane or hoist. Be certain the
crane or hoist is adequate for the task.
Best results will be obtained with this equipment ONLY if the responsible operating personnel have access to
this manual, and are familiar with these instructions. Additional copies may be obtained at a small cost per
copy by writing to: Hobart Brothers Company, Power Systems Division, Troy, Ohio Supply the owner’s
manual no.
(OM-2010)
plus the model, specification, and serial numbers of your equipment.
at once and file a claim for damages. If you require assistance with a
April 10/89 Revised 1-1
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OM-2010
1-1 April 10/89 Revised
Page 2
installation Dimension Drawing
Figure 1
OM-2010
SECTION 2. INSTALLATION
A. Location
For best operating characteristics and longest unit life, select an installation site that is not exposed to
high humidity, dust, high ambient temperature, flooding, or corrosive agents. Moisture can condense on
electrical components, causing corrosion or shorting of circuits. Dirt on components helps retain this moisture in addition to providing a conducting material.
Adequate air circulation is needed at all times in order to assure proper operation. Provide a minimum of
12 inches
ings are not obstructed.
(305mm)
of free air space at both front and rear of the unit. Make sure that the ventilator open-
B. Internal Wiring check
Refer to the product identification plate
power input voltages and frequency at which it will be operated.
(nameplate)
on the machine’s control panel to determine the
WARNING: ELECTRIC SHOCK CAN KILL. OPEN THE DISCONNECT SWITCH,
OR BREAKER, AND DETERMINE THAT NO VOLTAGE IS PRESENT, BEFORE
CONNECTING WIRES BETWEEN THE INPUT SERVICE AND POWER SUPPLY
OR WORKING ON THE POWER SUPPLY.
CAUTION: RECONNECTION OF CONTROL TRANSFORMER AS WELL AS MAIN INPUT CONNECTION PANEL MUST BE MADE WHEN CHANGING RATED INPUT VOLTAGE. SEE CHANGEOVER DIAGRAM.
Remove cabinet top for access to LINE VOLTAGE MAIN CHANGEOVER circuitry. Check line voltage
connections against instructions on the VOLTAGE CHANGEOVER DIAGRAM supplied with this manual.
If necessary, rearrange internal wiring and/or link connections to agree with the requirements for your input.
C. Connecting the Machine to Line Voltage
The input power should be connected to the input terminals on the lifting baffle via a suitable disconnecting means furnished by the user. Select the proper sized knock-out hole provided in the rear panel of the
machine to allow for the entry of the input conductors. Be certain the cable inside the power supply will
not contact the fan or hot parts. The lower holes may give a bit less weather leakage.
CAUTION: THE METHOD OF INSTALLATION, CONDUCTOR SIZE, AND OVERCURRENT PROTECTION SHALL CONFORM TO THE REQUIREMENTS OF THE LOCAL ELECTRICAL CODE,
THE NATIONAL ELECTRICAL CODE, OR OTHER NATIONAL CODES, AS APPLICABLE. ALL INSTALLATION WIRING AND MACHINE RECONNECTION SHALL BE DONE BY QUALIFIED PERSONS.
April 10/89 Revised 1-2
Page 1
OM-2010
Figure 1 provides minimal information for selection of line conductors, overcurrent protection, and the
equipment grounding conductor. This information is from the National Electrical Code NFPA 70-1981 Edition. Install this equipment per the latest edition, available from the National Fire Protection Association,
470 Atlantic Avenue, Boston, MA 02210.
Connect the three-phase line leads to terminals L1, L2, and L3 on the line contactor (top end) located on
the rear of the lifting baffle inside the power supply cabinet.
NOTE: After connecting the input cables, it is recommended that Hobart #904021 urethane coating be
sprayed on the connections at the line contactor to protect these connections from corrosion, fungus,
and contamination. Spraying these connections will also reduce the potential for arcing from dirt and
condensation.
Copper Copper
Rated Line Wire Size * Grounding
Line Amps Conductor
Volts In Conduit Flexible Cable Min. Size
208 86 No. 3 No. 3 No. 3
230 78 No. 4 No. 4 No. 4
460 39 No. 8 No. 8 No. 8
220 82 No. 4 No. 4 No. 4
380 47 No. 8 No. 8 No. 8
230 79 No. 4 No. 4 No. 4
460 39 No. 8 No. 8 No. 8
575 32 No. 8 No. 8 No. 8
Recommended Wire Size Table
Figure 1
* Conductor sizes listed are for 30 feet or less of each conductor in conduit and for conductors having
90C insulation, such as type FEP, FEPB, RHH, and THHN. For conductors having other insulation, or for
conductors longer than 30 feet, consult Hobart Brothers Company as to size required.
D. Grounding
The frame of this ground power unit should be grounded for personnel safety, and to assure operation of
the overcurrent protection. The grounding method, and the equipment grounding conductor size and type
shall conform to local and national codes. For the National Electrical Code, the equipment grounding conductor shall be green, green with a yellow stripe, or bare. If flexible power cable is used, use a cable assembly which includes the equipment grounding conductor. If metallic armored cable or conduit is used,
the metal sheathing or conduit must be effectively grounded per local and national codes.
Rubber-tire mounted equipment shall be grounded to conform to local national codes. The grounding assists in providing protection against line voltage electrical shock and static shock. The grounding serves to
discharge the static electric charge which tends to build up on rubber-tire mounted equipment. This static
charge can cause painful shock and lead to the erroneous conclusion that an electrical fault exists in the
equipment. An ungrounded cabinet can be at a lethal potential if a component fails electrically to the case.
1-2 April 10/89 Revised
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OM-2010
Ifa system groundis not available,consult the electricalcodeenforcementbodyfor instructions. The
groundpower unit shouldbe connectedperyour electricalcode to an adequate drivengroundrodor to a
waterpipethatentersthe groundnot morethan 10 feet
Theequipmentgroundingconductor size listed inFig.1 is a guideif no local ornationalcode is applicable.
Attachthe equipmentgrounding blockconductor to the stud providedadjacent to the fuse block.Deter-
mine that the groundwire sizeis adequate beforethe machineisused.
CAUTION:FOR SAFETYAND TO ASSUREADEQUATEVENTILATION,BESURETOREPLACECABINETTOP.
(3 meters)
from the machine.
E. OutputLeads
Useyourapplicable electrical codeto determinethe minimumsizeoutputcable youneed. Ifthe cablevoltage dropis too largewiththe minimum size cable, usea largersize cable. For example, the 90C rated insulation, 4/0 cablein a 40 C ambientneededfor 400ADC mayhave to be largerfor carryingthat
amperageover200 feet withless than 4.5 Voltscabledrop.
April10/89Revised 1-2
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1-2 April 10/89 Revised
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CHAPTER 2. DESCRIPTION AND
OPERATION
SECTION 1. DESCRIPTION
1. General
OM-2010
This manual describes a portable,
ply rated at a continuous output of 28-V, 600-A DC to an aircraft load or a battery load. The rated input
voltages, currents, and frequency along with weights and dimensions are given in the Specifications and
Capabilities Table in Figure 2. This book will generally refer to this equipment as a GPU-600 power supply or power supply. See Figure 1 for a descriptive drawing showing the major components or sub-assemblies generally present in the design. A detailed description of each design variation is given later.
The power supplies are usually identical or nearly so in appearance. The specification numbers relate to
different rated input power requirements, possible output rating changes, or limited component specification changes. The specification number consists of the number S
dash number added for each specification change, i.e., S6683-1 or 6883A-1 is the first design specification made in the series.
The phase angle control method for obtaining the DC output voltage is the use of silicon controlled rectifiers to select the desired portion of the voltage that has been stepped down by the main transformer to produce the DC voltage. As shown in Figure 1, the power supply consists of:
A. A punched and formed steel base
rear and steerable castor wheels
B. A formed and louvered steel front panel
ters.
C. A formed and louvered sheet steel rear panel
and the SCR assembly
(see Fig. 1)
(17, Fig. 3)
Solid State controlled, transformer-rectifier DC power sup-
(for specification)
(1, Fig. 1)
(3)
at the front.
are mounted inside the power supply.
with 10 inch
(4)
for mounting most of the accessible controls and me-
(5, Fig. 1)
(254 mm)
to which the fan assembly
6683 or 6883A with a
diameter wheels
(2)
near the
(18, 19, Fig. 3)
D. A sheet steel top panel
put terminal board
the input power is off.
E. A sheet steel left side panel
panel permits output cable connections.
F. A sheet steel right side panel
board
(9, Fig. 1)
ble hangers also mount to this panel.
G. A steel vertical lifting yoke
and rear panels.
April 10/89 Revised 2-1
(16, Fig. 3),
and to the fuse block on the silicon controlled rectifier assembly
(7, Fig. 1 and 15, Fig. 3)
snubber board
(11, Fig. 3),
(8, Fig. 1)
(3, Fig. 3)
(1, Fig. 5)
to which two cable hangers are mounted. A door in this
with access doors to the solid state control printed circuit
with baffle assembly attached to the base between the front
removable for access to the input fuses, main in-
and control transformer connections when
(10, Fig. 1)
. Two ca-
Page 1
OM-2010
1. Mounting Base 8. Side Panel (Right
2. Wheel Side Illustrated)
3. Caster 9. Front Access Door
4. Front Panel 10. Rear Access Door
5. Rear Panel 11. Lifting Yoke
6. Cable Hanger 12. Power Receptacle
7. Top Panel
General Assembly of GPU-600 Power Supply
2-1 April 10/89 Revised
Page 2
Figure 1
OM-2010
H. Various internal components such as the preload resistors
filter capacitors
Fig. 3)
input contactor
CAUTION: CAPACITOR CHARGE CAN INJURE! ALLOW CAPACITORS TO DISCHARGE AND
VERIFY CAPACITOR DISCHARGE WITH VOLTMETER BEFORE TOUCHING THE CAPACITOR
CIRCUITRY.
output contactor, control transformer
(4, Fig. 3)
(14, Fig. 3),
with the bus bar
etc.
(5, Fig. 3)
(10, Fig. 3),
at the front, filter reactor
(6, Fig. 3),
main transformer
(7, Fig. 3),
and printed circuit control board
(1, Fig. 3),
two
(13, Fig. 3),
2. Special Features
This DC ground power supply has the following special features which may be described more fully, if required, in the detailed description:
A. Output Ammeter, M1,
signal is provided by R11 meter shunt
B. Output Voltmeter, M2,
C. Input contactor,
D. 28-V DC contactor
E. Solid state closed loop feedback output voltage control to compensate for brown-outs and load re-
lated power supply voltage droop.
(2, Fig. 4)
(3, Fig. 4)
(14, Fig. 3)
(8, 9, Fig. 3)
with a 0-2000 A DC scale for reading the DC output amperes. The
(20, Fig. 3).
having a 0 to 50 V DC scale reading the DC output voltage.
with amber input contactor on-off light
with green output contactor on-off light
(12, Fig. 4)
(13, Fig. 4).
(8, 9,
F. Output overvoltage
G. Adjustable solid state output limit circuitry. The customer selects the momentary output limit in the
250 to 2000 A DC range by adjusting the R13 starting current potentiometer
age slope circuit causes a 25 percent drop in output voltage from 600 A DC to 1600 A DC output current.
CAUTION: EXCESSIVE CHARGING CURRENT CAN DAMAGE SOME TYPES OF BATTERIES
AND SOME OTHER LOADS. IF THE 250 A DC “STARTING SURGE” LEVEL IS TOO HIGH FOR
YOUR PARTICULAR LOAD, CONTACT THE MANUFACTURER FOR RECOMMENDATIONS.
H. Auxiliary power receptacle
this is a duplex receptacle rated at 115 V AC, 9-amperes, single phase. On the 50-Hz model, this is a
single output rated at 220 V AC, 15-amperes, single phase.
J. Thermal overload thermostat
overheats.
(31.5 V DC)
(5, Fig. 4)
(3, Fig. 5)
and overcurrent turn off circuitry and turn on DS2 trip light.
(8, Fig. 4).
with weather protection cover
which turns off the output voltage when the SCR heatsink
(7, Fig. 4)
A preset volt-
On the 60-Hz model,
April 10/89 Revised 2-1
Page 3
OM-2010
PHYSICAL
Weight (approximately) 650 pounds (295 kg)
Length 38 1/8 inches (968 mm)
Width 32 3/4 inches (832 mm)
Height (overall) 34 1/8 inches (867 mm)
ELECTRICAL SPECIFICATION NUMBER
INPUT S6883-1 S6883-2
S6883A-1 * S6883A-1 * S6883A-1 *
Cycles per second 60 50 60
Phase 3 3 3
Volts 208/230/460 220/380 230/460/575
Amperes 86/78/39 82/47 79/39/32
Power Factor at 28-V DC
output .68 .68 .68
Ground cable size See1-2 Fig. 2 See 1-2 Fig. 2 See 1-2 Fig 2
OUTPUT
Output Power Rating (max.) 17.1 KW 17.1 KW 17.1KW
Volts 28.5 V DC 28.5 V DC 28.5 VDC
Amperes (rated load) 600 A DC 600 A DC 600A DC
Duty cycle 100 % 100% 100%
Overload Capacity 125% of rated 125% of rated 125% of rated
load for 7 load for 7 load for 7
minutes. minutes. minutes.
* Series S6683A units are identical to corresponding Series 6683 units except for the PC control board assemblies. PC control board No. 180294 is used in Series S6683 units, and PC control board No. 180294A is used in Series S6683A units.
K. Input contactor coil fuse F8,
(F9)
for auxiliary power on 50 Hz.
L. Running gear consisting of two 10"
and two swivel mounted 6"
mounted near the front. A handle for pulling or guiding is fastened to the top front of the power supply.
(20, Fig. 3),
(152.4 mm)
auxiliary power and fan fuse F1
(254 mm)
diameter casters
diameter wheels
(3, Fig. 1),
(9, Fig. 4).
(2, Fig. 1)
one with a manual brake,
on the axle near the rear
Fuse, 10 amp
2-1 April 10/89 Revised
Page 4
3. Detailed Description
A. General
A detailed description of the parts used to build the power supply is given below. If a description applies only to power supplies having a particular specification number, reference to that specification
will be made. The specification number and equipment rating information is provided on the nameplate located on the power supply front panel just above the manufacturers name. Be certain that the
specification number and rating is proper for your input power rating. Also be sure that your output
voltage setting is properly rated for your load. Refer also to Figure 2 of this chapter for the tabulation
of rated values for the specifications listed.
This power supply utilizes solid state devices to control the output of the main transformer by delaying
the turn on time of the main siliconcontrolled rectifier to that required to give the desired power supply
output voltage. This control method is called SCR phase angle control.
The turn on delay after the voltage input to the SCR devices is quite similar to a phase shift. Generally, the longer the turn-on delay
factor. The printed circuit board has various data sent to it from sensors and/or points in the power
supply. These data are compared with the commands that the user has established so that instructions to correct any abnormality in output can be automatically provided.
(i.e., lower output voltage)
OM-2010
the lower the power supply input power
B. Main Transformer (1, Fig. 3)
The main power transformer is a forced air cooled, core-type, 3 phase unit that reduces the rated input voltage or voltages to a voltage somewhat higher than the maximum rated output voltage. The extra voltage for the output provides a reserve capability to compensate for undervoltage on the input
circuit, for the higher IR voltage drop found as the transformer, cables and other components heat up
with load and ambient temperature rises.
April 10/89 Revised 2-1
Page 5
OM-2010
1. Power Transformer 12. PC Mounting Panel
2. Left Side Panel 13. Printed Circuit Board
3. Lifting Yoke 14. Line Contactor
4. Capacitor 15. Top Panel
5. Terminal Output Assembly 16. Voltage Changeover Board
6. Resistor Assembly 17. SCR Heat Sink Assembly
7. Choke 18. Fan Blade
8. (Deleted) 19. Fan Motor
9. 28 V-DC Contactor 20. Control Transformer Fuse
10. Control Transformer 21. Ammeter Shunt
11. Right Side Panel
2-1 April 10/89 Revised
Page 6
Internal Components for GPU-600
Figure 3
OM-2010
1. Front Panel 8. R13 Start Level Control
2. M1 DC Ammeter 9. F1 Fuse
3. M2 DC Voltmeter 10. S1 Input On-Off Switch
4. DS2 Overload Light 11. S2 Output On-Off Switch
5. 115 VAC Receptacle 12.Input Power Light (amber)
6. MOV Surge Suppressor 13. Output Contactor Light (green)
7. 115 VAC Weather Cover
Front Panel Assembly, GPU-600
April 10/89 Revised 2-1
Figure 4
Page 7
OM-2010
The main transformer of the 208/230/460-V power supply
provide the 115-V AC for the auxiliary power receptacle and fan motor. The main transformer has a
center tapped coil on each phase that provides six sensing or synchronizing voltage signals to the
solid state printed circuit control board
The main transformer for the 220/380-V power supply
winding for its auxiliary power receptacle and a 110-V AC winding for the fan motor. Be certain to follow the changeover diagram for both the main transformer and the control transformer
the input voltage you have available.
CAUTION: IMPROPER CONNECTIONS WILL CAUSE DAMAGE. CONTACT FACTORY IF YOUR
EQUIPMENT SPECIFICATION INFORMATION AND/OR VOLTAGE CHANGEOVER DIAGRAM
DOES NOT AGREE WITH YOUR RATED 3 PHASE INPUT VOLTAGE.
C. Control Transformer (10, Fig. 3)
The small control transformer located on the rear of the inside baffle
vides 115 V AC to the K1
(11, Fig. 4)
former. This transformer does not provide the 9A, 115 V AC auxiliary power.
input contactor switch via the half amp F8 contactor fuse
(14, Fig. 3)
(13, Fig. 3).
input contactor coil, input contactor light A
(Spec 6683-1 or 6883A-1)
(Spec 6683-2 or 6883A -2)
(3, Fig. 3)
or lifting eye plate pro-
(20, Fig. 3)
has a winding to
has a 220-V AC
(10, Fig. 3)
(12, Fig. 4),
on the control trans-
and S1
WARNING: ELECTRIC SHOCK CAN KILL! DISCONNECT INPUT POWER AT
SOURCE TO REMOVE VOLTAGE TO CONTROL TRANSFORMER AND INPUT
FUSES AND CONTACTOR.
for
D. Auxiliary Power Circuitry
The 115 V AC single phase auxiliary power receptacle
mary input voltage. It is protected by the F1 fuse
typically, 15 Amperes. The auxiliary power circuitry is turned off whenever the primary contactor is
open or off. The auxiliary power winding is typically located on the middle leg
transformer. It provides power to the duplex 115 V AC receptacle
A “MOV” voltage surge suppressor, RV
nals to reduce voltage surge problems to the load equipment and the power source.
E. Output Contactor Circuitry
Output contactor K2
Placing this switch momentarily in the UP (spring-loaded) position turns the output contactor ON, and
placing it in the DOWN position turns the output contactor OFF.
The positive output lead is to be connected to the positive output terminal of the K2 contactor. The
negative output lead is to be connected to the negative bus bar
capacitor bank
to allow for the output cable assembly to pass out either side.
(9, Fig. 3)
(4, Fig. 3)
is operated by the output contactor ON-OFF switch S2
. A small notch has been made in the bottom of the right and left side panels
(6, Fig. 4),
(5, Fig. 4)
(9, Fig. 4)
is installed across the 115 V AC receptacle termi-
has the same frequency as the pri-
located on the power supply front panel,
(5, Fig. 4)
(B phase)
and to the fan motor.
of the main
(11, Fig. 4).
(5, Fig. 3)
of the C15-C17 output filter
2-1 April 10/89 Revised
Page 8
F. Output Filter Circuitry
OM-2010
The DC output voltage is smoothed
carrying the output current to the load and the ripple current to the C15, C16, C17 ripple bypass ca-
3)
pacitors
vide both a preload to the SCR devices
discharging the filter capacitors whenever the power supply is turned off.
CAUTION: CAPACITOR CHARGE CAN INJURE. BE SURE CAPACITORS ARE DISCHARGED
BEFORE TOUCHING.
The CR7 flyback diode
protect the main SCR rectifier assembly from damaging reverse voltage spikes.
G. Front Panel Control Components (See Fig. 4)
(1) Output Meter
(4, Fig. 3)
The power supply is typically supplied with a 0 to 2000 Amp scale DC ammeter M1
which measures the millivolt drop across the R11 meter shunt
scale calibration. The scale range is so much more than the rated output because the R13 starting current potentiometer
a maximum of 2000 amperes. The M2 output voltmeter
age across the main filter capacitors.
The scale typically has a 50 V DC maximum reading. It should be emphasized that the R12 control feedback shunt
ter control integrity.
in parallel with the load terminals. The R2, R3, R4 bypass resistors
(6, Fig. 5)
(21, Fig. 3)
(filtered)
by an L-C filter made up of L1 iron core reactor
(6, Fig. 3)
(2, Fig. 5)
acts to facilitate discharge of the output filter circuitry as well as to
and a safety discharge circuit for quickly
(21, Fig. 4)
(20, Fig. 3)
(8, Fig. 4)
can select any initial or starting current from 250 amperes to
(16, Fig. 4)
is not to be used for the meter shunt. This separation provides bet-
that corresponds to the
measures the DC output volt-
(7, Fig.
pro-
(2) Input Contactor Switch with Light
The S1 input contactor switch
plied by the control transformer via the F8 fuse. The amber input contactor light
whenever voltage is applied to the input contactor coil. The input contactor applies the rated input
voltage to main changeover board
(10, Fig. 4)
(16, Fig. 3).
controls the 115 V AC contactor pickup voltage sup-
(12, Fig. 4)
WARNING: ELECTRIC SHOCK CAN KILL! DISCONNECT THE INPUT POWER
FROM THE POWER SUPPLY BEFORE TOUCHING INTERNAL PARTS. THE INPUT CONTACTOR DOES NOT REMOVE ALL INPUT POWER FROM THE
UNIT. BE SURE ALL CAPACITORS HAVE DISCHARGED BEFORE TOUCHING
THE COMPONENTS.
(3) Output Contactor Switch and Light
The S2 output contactor close on-off switch
close mode, a middle position for “on” mode, and a bottom position for the “off” mode. The green
output contactor “on” light
(13, Fig. 4)
(11, Fig. 4)
glows for all the positions except “off”.
has a spring loaded up position for the
glows
April 10/89 Revised 2-1
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OM-2010
(4) Overload Trip Light (4, Fig. 4)
The overload trip light glows whenever the solid state printed circuit board turns off the power supply output due to output voltage exceeding 31.5 V DC, output current surge exceeding 2200-A
DC.
H.Main SCR Heat Sink Assembly (See Fig. 5)
The main SCR heat sink assembly is mounted on the front of the rear panel. It surrounds the 115 V
AC cooling fan assembly for optimum cooling efficiency. The SCR heat sink
formed aluminum heat sink with 6 “hockey puck” silicon controlled rectifiers held by 6 insulated compression spring assemblies held against it by 6 U-shaped aluminum heat sinks for the “hockey puck”
device cooling, two snubber pc board assemblies for SCR gate signal control and protection
the associated insulators, thermostats and hardware.
5),
(2, Fig. 5)
consists of a
(1, Fig.
The solid state printed circuit board
quenced turn on signal to the silicon controlled rectifiers that must conduct to provide the desired output. If the output voltage is too high or if the output current is above the limit set by controls such as
the R13 starting potentiometer, the “pcb” control delays the SCR turn-on signal to allow less SCR device conduction time for a correspondly lower output. Conversely, if the output voltage is too low, the
SCR turn-on signal is delivered earlier in the possible conduction time for each SCR thereby allowing
more power to be supplied because of the longer conduction time. Proper operation of the SCR devices requires phase sequence and presence of all 6 voltage sensing signals, proper phase sequence and presence of the output voltage to the SCR devices and the proper magnitude and
sequence of the SCR turn-on signal to the SCR gate leads.
J. Solid State Printed Circuit Control Board (13, Fig. 3)
The printed circuit board is located in a steel box behind the front access door on the power supply
right side panel
following functions:
(1) Electronic Overvoltage/Overload Trip Circuit
The “pc board” trips the power supply off and turns on DS-2 red overload trip light
the front panel if more than 31.5 V DC or 2200 A overload exists. To reset, correct the cause of
the condition and then turn the input switch off and back on.
(2) Electronically Controlled Current Limit
The starting current or output surge current is selected by adjusting R13 starting current control
(8, Fig. 4)
(2, Fig. 3).
on the front panel from the minimum 250 A DC to the maximum 2000 A DC.
This large printed circuit board is the “brains” or electronic control for the
(13, Fig. 3)
described later provides a properly timed and se-
(4, Fig. 4)
on
CAUTION: EXCESS STARTING CURRENT MAY CAUSE DAMAGE TO LOAD, BLOW FUSES OR
DAMAGE POWER SUPPLY. CONTACT FACTORY IF YOU REQUIRE A CURRENT LIMIT LOWER
THAN THE 250 A DC STANDARD MINIMUM LIMIT.
(3) Regulated DC Output Voltage
The voltage value is continuously compared to the actual output. If adequate input voltage exists,
deviation from the desired voltage output is corrected by the change in SCR conduction time set
by the printed circuit board firing pulse output. This corrective action is done quickly because the
control is done electronically with only limited stored energy in the circuitry. Typical response time
is about 25 milliseconds.
2-1 April 10/89 Revised
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