Unitec Peco HF25A User manual

USER'S MANUAL 990-333
Revision B December 2003
HF25A/HF25D 25kHz HIGH FREQUENCY
DC RESISTANCE WELDING SYSTEM
MODEL NUMBER STOCK NUMBER
HF25A10/240 1-280-02-03
HF25A10/400 1-280-02-04
HF25A10/480 1-280-02-05
HF25DA10/240 1-285-02
HF25DA10/400 1-285-02-01
HF25DA10/480 1-285-02-02

HF25D DC RESISTANCE WELDING SYSTEM
ii 990-333
Copyright © 1998, 2003 Unitek Miyachi Corporation
The engineering designs, drawings and data contained herein are the
proprietary work of UNITEK MIYACHI CORPORATION and may not
be reproduced, copied, exhibited or otherwise used without the written
authorization of UNITEK MIYACHI CORPORATION.
Printed in the United States of America.
Revision Record
Revision EO Date Basis of Revision
A 19826 9/03 None. Original edition.
B 19895 12/03 Updated LVDT Option information.

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CONTENTS
Page
Chapter 1. Description
Section I: Features .................................................................................................................................. 1-1
Section II: Major Components ............................................................................................................... 1-4
Major Components .......................................................................................................................... 1-4
Front Panel Display and Display Controls ......................................................................................1-4
Display ..................................................................................................................................... 1-5
Display Controls ....................................................................................................................... 1-6
SCHEDULE Selector Key ................................................................................................ 1-6
Weld Period Selector Keys ............................................................................................... 1-6
Time/Energy Selector Keys .............................................................................................. 1-6
Front Panel Data Entry and Mode Controls ............................................................................. 1-7
Key Pad .................................................................................................................................... 1-7
Numeric Keys .................................................................................................................... 1-7
Up/Down Keys .................................................................................................................. 1-7
Mode Key ................................................................................................................................. 1-7
RUN Key ........................................................................................................................... 1-7
MENU Key ....................................................................................................................... 1-7
Control Keys ............................................................................................................................. 1-7
Energy Units Selection Keys ............................................................................................. 1-7
KA .............................................................................................................................. 1-7
V ................................................................................................................................. 1-7
KW ............................................................................................................................. 1-8
Monitor Keys ............................................................................................................................ 1-8
KA ..................................................................................................................................... 1-7
V ..................................................................................................................................... 1-8
KW .................................................................................................................................... 1-8
Resistance (Ω) ................................................................................................................... 1-8
Peak/Average .................................................................................................................... 1-8
LVDT Keys .............................................................................................................................. 1-9
Distance ............................................................................................................................. 1-9
New Electrode ................................................................................................................... 1-9
Quick Cal ........................................................................................................................... 1-9
WELD/NO WELD Switch ....................................................................................................... 1-9
Emergency Stop Switch Operation .......................................................................................... 1-9
Chapter 2. Getting Started
Section I: Planning for Installation ........................................................................................................ 2-1
Space Requirements ......................................................................................................................... 2-1
Utilities ..................................................................................................................................... 2-2
Power ..................................................................................................................................... 2-2
Compressed Air and Cooling Water ......................................................................................... 2-2

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Contents (Continued)
Page
Section II: Setup ..................................................................................................................................... 2-3
Connections to External Equipment ................................................................................................ 2-3
Weld Head Connections .................................................................................................................. 2-4
Foot Pedal-Actuated Weld Head Connection .................................................................................. 2-6
Air-Actuated Weld Head Connection .............................................................................................. 2-7
Chapter 3. Using Programming Functions
Section I: Menus .................................................................................................................................... 3-1
Overview ..................................................................................................................................... 3-1
Main Menu ..................................................................................................................................... 3-1
1. Setup .................................................................................................................................... 3-1
2. Weld Counter ....................................................................................................................... 3-2
3. Copy A Schedule ................................................................................................................. 3-2
4. System Security ................................................................................................................... 3-3
1. Schedule Lock .............................................................................................................. 3-3
2. System Lock ................................................................................................................. 3-3
3. Calibration Lock ........................................................................................................... 3-3
5. Communication ................................................................................................................... 3-4
1. Communication Role .................................................................................................... 3-4
2. I.D. Number .................................................................................................................. 3-5
3. Baud Rate ...................................................................................................................... 3-5
6. Relay .................................................................................................................................... 3-6
7. Calibration ............................................................................................................................ 3-6
8. Reset To Defaults ................................................................................................................ 3-7
1. Reset System Parameters ............................................................................................. 3-7
2. Reset All Schedules ...................................................................................................... 3-7
9. Chain Schedules .................................................................................................................. 3-8
Setup 1 ................................................................................................................................... 3-10
1. Footswitch Weld Abort ..................................................................................................... 3-10
2. Switch Debounce Time ..................................................................................................... 3-10
3. Firing Switch ..................................................................................................................... 3-11
1. Auto ............................................................................................................................ 3-11
2. None ........................................................................................................................... 3-11
3. Remote ....................................................................................................................... 3-11
4. Input Switch Select ............................................................................................................ 3-11
1. Mechanical ................................................................................................................. 3-12
2. OPTO ......................................................................................................................... 3-12
3. PLC ............................................................................................................................. 3-12
5. Control Signals Select ....................................................................................................... 3-13
Setup 2 ................................................................................................................................... 3-13
1. Display Contrast ................................................................................................................ 3-13
2. Buzzer Loudness ............................................................................................................... 3-13
3. End Of Cycle Buzzer ......................................................................................................... 3-13
4. Update Graph After Weld ................................................................................................. 3-14

HF25D DC RESISTANCE WELDING SYSTEM
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Page
Section II. Operational States .............................................................................................................. 3-15
No Weld State ................................................................................................................................ 3-15
Menu State ................................................................................................................................... 3-15
Test State ................................................................................................................................... 3-15
Run State ................................................................................................................................... 3-16
Weld State ................................................................................................................................... 3-17
Monitor State ................................................................................................................................. 3-17
Alarm State ................................................................................................................................... 3-18
Section III. Weld Functions ................................................................................................................. 3-19
Welding Applications .................................................................................................................... 3-19
Weld Head Applicability ............................................................................................................... 3-20
Section IV: Using Weld and Monitor Functions ................................................................................. 3-21
Overview ................................................................................................................................... 3-21
Weld Schedule Definition .............................................................................................................. 3-22
Weld Sequence Timing .................................................................................................................. 3-22
Welding Applications .................................................................................................................... 3-23
Single-Pulse Weld Profile ...................................................................................................... 3-23
Upslope/Downslope Weld Profile .......................................................................................... 3-24
Dual-Pulse Weld Profile ......................................................................................................... 3-24
Section V. Programmable Feedback Modes ........................................................................................ 3-26
Introduction ................................................................................................................................... 3-26
Current Mode ................................................................................................................................. 3-26
Voltage Mode ................................................................................................................................ 3-26
Power Mode ................................................................................................................................... 3-26
Section VI. Weld Monitor .................................................................................................................... 3-27
Introduction ................................................................................................................................... 3-27
Active Part Conditioner (APC) ...................................................................................................... 3-27
How It Works ......................................................................................................................... 3-28
Energy Limits ................................................................................................................................ 3-29
Pre-Weld Check ............................................................................................................................. 3-30
Chapter 4. Operating Instructions
Section I: Before You Start ............................................................................................................. 4-1
Initial Setup: Pre-Operational Checks ..................................................................................... 4-2
Connections ....................................................................................................................... 4-2
Power ................................................................................................................................. 4-2
Compressed Air ................................................................................................................. 4-2
Initial Setup Instructions ........................................................................................................... 4-2
Section II. Programming Weld Schedules ...................................................................................... 4-3
Introduction .............................................................................................................................. 4-3
Select a Weld Schedule ..................................................................................................... 4-3
Enter New Values .............................................................................................................. 4-3

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Contents (Continued)
Page
Single-Pulse Weld Schedule ..................................................................................................... 4-4
Upslope/Downslope Weld Schedule ........................................................................................ 4-5
Dual-Pulse Weld Schedule ....................................................................................................... 4-6
Section III. Programming the Weld Monitor .................................................................................. 4-7
Section IV. Programming For Active Part Conditioning ............................................................... 4-9
Section V. Adjusting Monitor Limits ........................................................................................... 4-11
Chapter 5. User Maintenance
Section I: Introduction ........................................................................................................................... 5-1
General Kinds of Problems .............................................................................................................. 5-1
Alarm Messages ............................................................................................................................... 5-1
Section II: Troubleshooting ................................................................................................................... 5-2
Troubleshooting ............................................................................................................................... 5-2
Alarm Messages ............................................................................................................................... 5-3
Section III: Maintenance ........................................................................................................................ 5-9
Electrode Maintenance .................................................................................................................... 5-9
Parts Replacement ........................................................................................................................... 5-9
Section IV: Maintenance ...................................................................................................................... 5-10
Chapter 6. Calibration
Calibration ..................................................................................................................................... 6-1
Calibration Equipment Required ..................................................................................................... 6-1
Calibration Procedure ..................................................................................................................... 6-2
Calibrating the LVDT ...................................................................................................................... 6-4
Appendix A. Technical Specifications ............................................................................................... A-1
Appendix B. Electrical and Data Connections ..................................................................................B-1
Appendix C. System Timing ...............................................................................................................C-1
Appendix D. LVDT Option ................................................................................................................ D-1
Appendix E. Communications ............................................................................................................E-1
Appendix F. The Basics of Resistance Welding ................................................................................ F-1
Appendix G. Quality Resistance Welding Solutions: Defining the Optimum Process ................ G-1

HF25D DC RESISTANCE WELDING SYSTEM
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CONTACT US
Thank you for purchasing a Unitek Peco™ Resistance Welding System Control.
Upon receipt of your equipment, please thoroughly inspect it for shipping damage prior to its
installation. Should there be any damage, please immediately contact the shipping company to file a
claim, and notify Unitek Miyachi at:
1820 South Myrtle Avenue
P.O. Box 5033
Monrovia, CA 91017-7133
Telephone: [phone]
FAX: [phone]
e-mail: [email protected]
The purpose of this manual is to supply operating and maintenance personnel with the information
needed to properly and safely operate and maintain the Unitek Peco HF25 Resistance Welding System
Control.
We have made every effort to ensure that the information in this manual is accurate and adequate.
Should questions arise, or if you have suggestions for improvement of this manual, please contact us at
the above location/numbers.
Unitek Miyachi Corporation is not responsible for any loss due to improper use of this product.

HF25D DC RESISTANCE WELDING SYSTEM
viii 990-333
SAFETY NOTES
DANGER
•Lethal voltages exist within this unit.Do not perform any maintenance
inside this unit.
•Never perform any welding operation without wearing protective safety
glasses.
This instruction manual describes how to operate, maintain and service the HF25 Resistance Welding
System Control, and provides instructions relating to its SAFE use. A separate manual provides similar
information for the Weld Head used in conjunction with the Power Supply. Procedures described in
these manuals MUST be performed, as detailed, by QUALIFIED and TRAINED personnel.
For SAFETY, and to effectively take advantage of the full capabilities of the Weld Head and Power
Supply, please read these instruction manuals before attempting to use them.
Procedures other than those described in these manuals or not performed as prescribed in them, may
expose personnel to electrical, burn, or crushing hazards.
After reading these manuals, retain them for future reference when any questions arise regarding the
proper and SAFE operation of the Power Supply.
Please note the following conventions used in this manual:
WARNING: Comments marked this way warn the reader of actions which, if not followed, might
result in immediate death or serious injury.
CAUTION: Comments marked this way warn the reader of actions which, if not followed, might result
in either damage to the equipment, or injury to the individual if subject to long-term exposure to the
indicated hazard.

HF25D DC RESISTANCE WELDING SYSTEM
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HF25D DC RESISTANCE WELDING SYSTEM
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CHAPTER 1
DESCRIPTION
Section I: Features
Features
For the rest of this manual, the Unitek HF25
High Frequency Resistance Welding System
control will simply be referred to as the Control.
•The Control is a 25 kHz, three-phase, state-
of-the-art inverter power supply for joining
precision small parts at high speed with
controllable rise times. The delivered
welding energy is in the form of DC welding
energy. High speed (50 microsecond)
digital feedback automatically controls weld
current, voltage, or power, providing more
welding consistency compared to traditional
direct energy (AC) or capacitive discharge
(CD) technologies.
•Microprocessor technology automatically
compensates for changes in work piece
resistance, load inductance, weld
transformer saturation, and changes in line
voltage. Special power device technology
precisely controls the weld energy at both
high and low energy levels.
•Easy to use constant weld current, voltage,
or power feedback ensures repeatable
welding and has proven to extend electrode
life in many applications by a factor of 3 or
more.
HF25D Front Panel

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HF25D DC RESISTANCE WELDING SYSTEM
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•You can program the Control from the front
panel, using simplified key clusters and on-
screen data fields. A MAIN MENU screen
allows you select all of the system setup
options for working with inputs from
external equipment.
<MAIN MENU>
1. SETUP 5.
COMMUNICATION
2. WELD COUNTER 6. RELAY
3. COPY A SCHEDULE 7. CALIBRATION
4. SYSTEM SECURITY 8. RESET TO
DEFAULTS
NUMBER Select an item
•The RUN screen allows you to easily modify
any time period, current, voltage, or power
value.
Run Screen
•The MONITOR screen provides instant visual
feedback on the actual current, voltage, or
power used to make each weld. It permits
you to program adjustable limits for both
weld pulses.
Monitor Screen
•Rear-mounted RS-232 and RS-485 connectors allow for remote programming, weld schedule
selection, and data logging for SPC purposes. The Control has communication and data options
that allows you to connect a single Control, or multiple Controls, to a printer or a computer in
order to:
−Compile, store, view, and print weld history data for detailed analysis.
−Remotely program weld schedules on the Control(s).
−Remotely program menu items on the Control(s).
However, to enable the Control to perform these functions, you must install the software from the
optional HF25 Advanced Serial Datacom Communications Interface Kit, commonly referred to as
"the Datacom kit," in a host computer.
Appendix E, Communications in this manual lists all of the commands that the Control will respond
to, and instructions on how to format commands sent to the Control so it will respond properly.

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HF25D DC RESISTANCE WELDING SYSTEM
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•The Control has a Linear Variable Differential Transformer (LVDT) option that allows the
user to:
−Measure Initial Part Thickness
−Measure Final Part Thickness
−Measure displacement during welding
−Stop the weld energy after a programmable displacement is reached.
Programmable relay outputs are also provided with this option. For details see Appendix D, LVDT
option.
•The design of the Control is directed toward compactness, lightweight, operational simplicity, and
ease of repair. Metric hardware is used throughout the chassis to facilitate international servicing
and repair.
•The 25 kHz operating frequency ensures that the integral welding transformer is light and compact.
The input/ output connector box on the rear panel is easily removable for replacement by quick-
connect signal I/O cabling, facilitating interface with automation systems.
I/O Connector Box (Rear Panel)

CHAPTER 1: DESCRIPTION
HF25D DC RESISTANCE WELDING SYSTEM
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Section II: Major Components
Major Components
The major components are the front panel, which contains the operator’s controls and indicators, and the
rear panel, which contains fuses, circuit breakers and power and signal connectors. The rear panel
connections are discussed in Chapter 2.
Front Panel Display and Display Controls
The front panel of the Control below shows controls and indicators. The function of each item is
described on the following pages.
Front Panel Controls

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Display
Liquid Crystal Display (LCD)
The Liquid Crystal Display (LCD) on the front panel allows you to locally program the Control with the
front panel controls, and read the results of a weld process following its initiation.
The LCD has three distinct functions, depending on the active mode of the Control. In the run mode, the
display permits you to:
•View the entire weld schedule profile, individual weld periods, and weld energy parameters.
•View individual weld parameter program changes as you enter them via the weld period
selector keys.
•View completed weld feedback data and use the data to modify the weld schedule.
In the menu mode, the display presents system setup options for you to select. In the monitor mode, the
display is your means of programming the energy limits monitor and viewing actual out of limit
conditions.

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HF25D DC RESISTANCE WELDING SYSTEM
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Display Controls
There are three display control functions:
•SCHEDULE Selector Key
•Weld Period Selector Keys
•Time/Energy Selector Keys
SCHEDULE Key
Puts the Control into the weld schedule selection mode. Use the
keypad to directly enter a desired weld schedule (refer to Front Panel
Data Entry and Mode Controls in this section), then press the RUN
key.
Weld Period Selector Keys
Select individual weld periods and weld energy fields in the weld schedule profile for programming.
See Front Panel Data Entry and Mode Controls.
Time/Energy Selector Keys
These two switches, one for each of the PULSE 1 and PULSE 2 weld
periods, select either the bottom line of data or the second-to-bottom
line of data on the screen to be programmed. The bottom line of data
is weld period time in milliseconds. The second-to-bottom line is
Weld Energy, in the units selected by the energy units selection keys.
See Front Panel Data Entry and Mode Controls.

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Front Panel Data Entry and Mode Keys
Key Pad
The keypad consists of the numeric keys and the up/down keys.
Numeric Keys: The numeric keys allow you to:
•Enter or modify weld period time and energy values
•Enter or modify monitor and limit values
•Directly recall a specific weld schedule.
To use the numeric keypad, you must first select a time/energy weld period key or
the schedule key.
Up/Down Keys: The up/down keys allow you to increment (up) or decrement
(down) numeric values on the display, to change states, such as OFF to ON (up)
or ON to OFF (down); and to scroll the schedule number up and down while in
the run mode.
Mode Keys. The mode keys consist of the RUN key and the MENU key.
RUN Key: Sets the Control to the operating mode.
MENU Key: You access the menu screen with this key. Menu items control
system parameters such as setup and weld counter operation. Refer to Menus in
Chapter 3, Section II for details of the functions accessible through that screen.
Control Keys
Energy Units Selection Keys. These keys allow you to select the control mode when programming
with the WELD (time/energy) selector keys.
Pressing the kA key selects current as the control mode for this schedule. The
control will output the current waveform shown on the LCD.
Pressing the Vkey selects voltage as the control mode for this schedule. The
control will output the voltage waveform shown on the LCD.

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NOTE: Selecting the voltage feedback mode requires you to make a test weld
when the voltage or weld pulse time is changed. The test weld optimizes the
Control feedback performance. The weld status message TEST disappears after
the internal control parameters are optimized.
Pressing the kW key selects power as the control mode for this schedule. The
control will output the power waveform shown on the LCD.
Monitor Keys
These keys allow you to view the results of the last weld and to set the limits of the welding parameters
beyond which the energy limits monitor terminate the weld and/or initiate alarms.
Pressing the kA key displays the current monitor. This screen shows the results of
the most recent weld. This screen also allows the operator to set limits that
automatically interrupt the weld when they are reached. You can also program
the current monitor to output an alarm when the limits are exceeded.
Pressing the Vkey displays the voltage monitor. This screen shows the results of
the most recent weld. This screen also allows the operator to set limits that
automatically interrupt the weld when they are reached. You can also program
the voltage monitor to output an alarm when the limits are exceeded.
Pressing the kW key displays the power monitor. This screen shows the results of
the most recent weld. This screen also allows the operator to set limits that
automatically interrupt the weld when they are reached. You can also program
the power monitor to output an alarm when the limits are exceeded.
Pressing the Ωkey displays the resistance monitor. This screen shows the results
of the most recent weld.
Pressing this key selects either peak welding energy or average welding energy to
be monitored by the energy limits monitors.

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LVDT Keys
Pressing DISTANCE displays the displacement monitor. This screen shows the
results of the most recent weld. This screen also allows the operator to set limits
that automatically interrupt the weld when they are reached. You can also
program the power monitor to output an alarm when the limits are exceeded
Pressing NEW ELECTRODE allows the operator to reset the zero point for distance
measurement. This is useful when electrodes are changed and the new electrode
may be slightly longer or shorter than the old one.
Pressing QUICK CAL enters the displacement calibration routine. This routine sets
a new zero point for the distance measurement and calibrates the measurement.
WELD/NO WELD Switch
When the switch is in the WELD position, the programmed weld sequence can
initiate weld energy.
When you set this switch to the NO WELD position, no weld current can flow.
However, the Control can execute a complete weld sequence. This function is
required to adjust the weld head prior to operation.
Emergency Stop Switch Operation
If your work station is equipped with an emergency stop switch (connected to the emergency stop
connection of the Control), operate the switch to immediately stop the welding process. All power to
the air valves and power circuits will be disconnected. To restart the Control, you must press the RUN
key on the front panel.