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
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.
HF25D DC RESISTANCE WELDING SYSTEM
ii 990-333
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
HF25D DC RESISTANCE WELDING SYSTEM
990-333 iii
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
iv 990-333
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
HF25D DC RESISTANCE WELDING SYSTEM
990-333 v
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
vi 990-333
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: (626) 303-5676
FAX: (626) 358-8048
e-mail: info@unitekmiyachi.com
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
990-333 vii
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
viii 990-333
HF25D DC RESISTANCE WELDING SYSTEM
990-333 ix
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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CHAPTER 1: DESCRIPTION
• 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.
• The RUN screen allows you to easily modify
any time period, current, voltage, or power
value.
<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
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.
HF25D DC RESISTANCE WELDING SYSTEM
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CHAPTER 1: DESCRIPTION
• 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)
HF25D DC RESISTANCE WELDING SYSTEM
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CHAPTER 1: DESCRIPTION
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.
HF25D DC RESISTANCE WELDING SYSTEM
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Front Panel Controls
CHAPTER 1: DESCRIPTION
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.
HF25D DC RESISTANCE WELDING SYSTEM
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CHAPTER 1: DESCRIPTION
Display Controls
There are three display control functions:
• SCHEDULE Selector Key
• Weld Period Selector Keys
• Time/Energy Selector Keys
SCHEDULE 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
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.
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.
HF25D DC RESISTANCE WELDING SYSTEM
1-6 990-333
CHAPTER 1: DESCRIPTION
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 V key selects voltage as the control mode for this schedule. The
control will output the voltage waveform shown on the LCD.
HF25D DC RESISTANCE WELDING SYSTEM
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CHAPTER 1: DESCRIPTION
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 V key 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 Ω key 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.
HF25D DC RESISTANCE WELDING SYSTEM
1-8 990-333
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
CHAPTER 1: DESCRIPTION
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.
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CHAPTER 2
INSTALLATION AND SETUP
Section I: Installation
Unpacking
The Control is shipped to you completely assembled, together with the accessories you ordered and a
shipping kit. The contents of the shipping kit, available accessories, and contents of the Datacom Kit are
listed in Appendix A, Technical Specifications. Be sure that the accessories that you ordered have been
packed and the contents of the shipping kit and Datacom kit are as listed.
Verify that the Control shows no signs of damage. If it does, please contact the carrier. Also, contact
Unitek Miyachi Customer Service immediately at the postal or e-mail address or telephone or FAX
number shown in the Foreword of this manual.
Space Requirements
We recommend that the Control be installed in a well-ventilated area that is free from excessive dust,
acids, corrosive gases, salt and moisture. Other installation considerations are:
• Allow sufficient clearance around both sides and back of the Control for power and signal
cabling runs.
• Allow ample workspace around the Control so that it will not be jostled or struck while
welding. The dimensions of the Control are:
Height: 12.8 in. (325 mm)
Width: 9.0 in. (229 mm)
Depth: 18.0 in. (457 mm)
• The work surface must be level, stable, free from vibration, and capable of supporting the
combined weight of the total welding system. The weight of the Control is 62 lbs. (28 kg).
• The Control must be far enough from the weld head to avoid contact with weld splash.
• There are no sources of high-frequency energy close by.
HF25D DC RESISTANCE WELDING SYSTEM
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CHAPTER 2: INSTALLATION AND SETUP
Utilities
Power
Because of the different electrical requirements for the countries in which the Control is used, the
Control is shipped without a power cable connector. The required connections for your power cable
connector are described in Appendix B, Electrical and Data Connections. Input power requirements for
the Control are as listed below.
Power Input Specifications
Input Voltage,
HF25 Model
HF25A10/240 240 25 10 2.5 6.3 330-096
HF25A10/400 400 20 10 2.5 3.15 330-095
HF25A10/480 480 13 10 2.5 3.15 330-097
50-60 Hz,
3 phase
(Vrms)
Ckt Brkr
Current (A rms)
Copper Wire
Gauge,
7 strands (AWG)
Wire Dia
(mm)
Fuses F1, F2
Amps/
Volts
Unitek Peco
P/N
Compressed Air and Cooling Water
If you require compressed air and cooling water service for the weld head, please refer to the weld head
manufacturer’s user’s manual for service specifications.
HF25D DC RESISTANCE WELDING SYSTEM
2-2 990-333
CHAPTER 2: INSTALLATION AND SETUP
Section II: Setup
Connections to External Equipment
All connections, other than the weld cable connections, between the Control and external equipment are
made through the rear panel.
Rear Panel Components
The weld cable connections from the weld head are made at the weld cable terminals on the front panel.
HF25D DC RESISTANCE WELDING SYSTEM
990-333 2-3
CHAPTER 2: INSTALLATION AND SETUP
Weld Head Connections
1. Connect one end of a weld cable to the negative (-) welding transformer terminal on the
Control.
2. Connect one end of the second weld cable to the positive (+) welding transformer terminal on
the Control.
3. Connect the other end of the weld cables to the weld head.
4. Attach the voltage sensing cable connector to the VOLTAGE SENSE INPUT connector.
5. Install electrodes in the weld head electrode holders.
NOTE: If you need additional information about the weld heads, please refer to their user’s
manuals.
HF25D DC RESISTANCE WELDING SYSTEM
2-4 990-333
6. Connect the voltage sensing cable clips
that are packed in the shipping kit to the
voltage sensing cable leads. Use either the
¼” or 1/8” diameter clip, as appropriate to
the electrode diameter.
7. Attach a clip directly to each electrode as
shown on the right.
8. Put a strain relieve on each voltage sensing
lead to its corresponding electrode holder
so that the lead clips will not break away
under heavy operating conditions.
NOTE: Do not attach the firing
switch, foot switch or
STOP
cables at this time.
EMERGENCY
CHAPTER 2: INSTALLATION AND SETUP
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CHAPTER 2: INSTALLATION AND SETUP
Foot Pedal-Actuated Weld Head Connection
1. Adjust the weld head force adjustment knob to produce 5 units of force, as displayed on the
force indicator index.
2. Connect the weld head firing switch cable connector to the Control firing switch cable
connector.
3. Adjust the weld head force adjustment knob to produce 5 units of force, as displayed on the
force indicator index.
4. Connect the weld head firing switch cable connector to the Control firing switch cable
connector.
5. Adjust the weld head force adjustment knob to produce 5 units of force, as displayed on the
force indicator index.
6. Connect the weld head firing switch cable connector to the Control firing switch cable
connector.
7. Connect a normally closed, approved, emergency stop switch across the two leads of the
operator emergency stop switch cable. This switch, when operated (open), will immediately
stop the weld cycle. See Appendix B. Electrical and Data Connections for circuit details.
8. Set the
position, the Control cannot deliver weld energy, but it can control the weld head.
WELD/NO WELD switch on the Control front panel to the NO WELD position. In this
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CHAPTER 2: INSTALLATION AND SETUP
9. Set the circuit breaker on the rear panel
of the Control to the ON position. The
default
You will use this screen to enter
welding parameters. See Chapter 3,
Using Weld Functions and Chapter 4,
Operating Instructions.
RUN screen will be displayed.
Air-Actuated Weld Head Connections
1. Adjust the weld head force adjustment knob to produce 5 units of force, as displayed on the
force indicator index.
2. Connect the weld head firing switch cable connector to the Control firing switch cable
connector.
3. Connect a normally closed, approved, emergency stop switch across the two leads of the
operator emergency stop switch cable. This switch, when operated (open), will immediately
stop the weld cycle and retract the weld head. See Appendix B. Electrical and Data
Connections for circuit details.
4. Connect a Model FS2L Foot Switch to the Control FOOT SWITCH connector.
HF25D DC RESISTANCE WELDING SYSTEM
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CHAPTER 2: INSTALLATION AND SETUP
5. Refer to the weld head manufacturer user’s manual. Connect the weld head air valve solenoid
cable connector to the Control AIR VALVE DRIVER connector.
NOTE: This connector supplies 24 VAC power only, and will not drive 115 VAC air valves.
6. Connect a properly filtered air line to the air inlet fitting on the weld head. Use 0.25 inch O.D.
by 0.17 inch I.D. plastic hose with a rated burst pressure of 250 psi. Limit the length of the air
line to less than 40 in. (1 m) or electrode motion will be very slow.
NOTE: Use a lubricator only with automated installations.
7. Turn on the air system and check for leaks.
8. Set the
WELD/NO WELD switch on the Control front panel to the NO WELD position. In this
position, the Control cannot deliver weld energy, but it can control the weld head.
9. Set the circuit breaker on the rear panel
of the Control to the ON position. The
default
RUN screen will be displayed.
See Chapter 3, Using Weld Functions
and Chapter 4, Operating Instructions.
10. Turn the air regulator clockwise to produce 10 psi on the air regulator pressure gauge.
11. Press the foot switch all the way down to close both levels, and hold the foot switch down.
When the weld head upper electrode rises to the UP position, release the foot switch. Proceed
to Step 13. If it does not rise to the UP position, proceed to Step 12.
12. Increase air pressure in 5 psi increments and repeat Step 11 until the upper electrode rises to the
UP position.
13. Press the foot switch to actuate the first level. The weld head upper electrode should descend
smoothly to the DOWN position. When it reaches the down position, release the foot switch
and proceed to Step 15. If it does not descend smoothly, proceed to Step 14.
14. Adjust the weld head down speed control knob and repeat Step 13 until the upper electrode
descends smoothly.
15. Press the foot switch to actuate the first level and set the upper electrode to the DOWN
position. Release the foot switch and verify that upper electrode holder does not impact the UP
home position.
16. Repeat Step 15, adjusting the weld head up speed control knob until the upper electrode holder
does not impact at the UP home position.
HF25D DC RESISTANCE WELDING SYSTEM
2-8 990-333
USING PROGRAMMING FUNCTIONS
Overview
CHAPTER 3
Section I: Menus
You program the Control through the MAIN
MENU
screen and its sub-menus. You go to the
MAIN MENU screen by pressing the MENU key on
the front panel of the Control.
All of the menu screens have similar prompts
that tell you how to go to a function on the menu
1. SETUP 5. COMMUNICATION
2. WELD COUNTER 6. RELAY
3. COPY A SCHEDULE 7. CALIBRATION
4. SYSTEM SECURITY 8. RESET TO DEFAULTS
9. CHAIN SCHEDULES
NUMBER Select an item
MAIN MENU
and/or get to the next menu.
• At the NUMBER Select an item prompt, use the numeric keypad to select one of the functions on
the menu.
• Press the down keys to go to the next or previous menu. Each additional menu gives you
choices for additional functions.
• Press the MENU key to return to the main menu.
Main Menu
1. SETUP
From the MAIN MENU screen, press 1 to go to the
SETUP 1 screen.
The SETUP 1 screen is shown on the right with
typical settings.
1. FOOTSWITCH WELD ABORT : ON
2. SWITCH DEBOUNCE TIME : 10 ms
3. FIRING SWITCH : NORMAL
4. INPUT SWITCH SELECT : MECH OPEN
5. CONTROL SIGNALSEL ECT : MECH OPEN
NUMBER Select, MENU Main menu, W Page 2
<SETUP 1>
From the SETUP 2 screen, go to the SETUP 1
screen then press the key.
The SETUP 2 screen is shown on the right with
typical settings.
HF25 DC RESISTANCE WELDING SYSTEM
990-333 3-1
<SETUP 2>
1. DISPLAY CONTRAST : 075%
2. BUZZER LOUDNESS : 015%
3. END OF CYCLE BUZZER : OFF
4. UPDATE GRAPH AFTER WELD : ON
NUMBER Select, MENU Main menu, VPage 1
CHAPTER 3: USING PROGRAMMING FUNCTIONS
2. WELD COUNTER
1. From the MAIN MENU, press the 2 key
to go to the WELD COUNTERS screen.
The total welds counter increments each
time a weld is made in any weld
schedule.
1. TOTAL WELDS : 0000000
2. OUT OF LIMITS HIGH : 000000
3. OUT LIMITS LOW : 000000
4. WITHIN LIMITS : 000000
NUMBER Select, MENU Previous menu
<WELD COUNTERS>
NOTE: The Control breaks down the weld count into three additional categories, as
determined by the energy limits monitor: rejects due to higher than programmed weld energy,
rejects due to lower than programmed weld energy, and the number of acceptable welds.
2. To select the weld counters, press the 1, 2, 3 or 4 key to select the desired weld counter.
The example to the right shows the TOTAL WELDS screen.
3. To reset the counter, press the 0 key.
4. To input a preset number, use the
numeric keys.
5. If you accidentally reset the wrong
counter, press the period (.) key. The
original count will reappear. Press the
MENU key to return to the MAIN MENU
1. TOTAL WELDS : 0017429
NUMBER Change, . Restore, MENU Menu
WELD COUNTER>
screen.
3. COPY A SCHEDULE
The Control can store 99 (numbered 1 through
99) individual weld energy profiles. This
function allows you to copy any weld schedule
from one numbered weld schedule to another
numbered weld schedule
1. From the
go to the
MAIN MENU, press the 3 key to
COPY SCHEDULE screen.
2. Using the numeric keys, enter 1 in the
source schedule number field.
3. Press the
SCHEDULE key to select the
destination schedule number field.
4. Using the numeric keys, enter
2 in the
COPY SCHEDULE [ 1 ] TO SCHEDULE [2 ]
NUMBERS followed by SCHEDULE
COPY SCHEDULE [ 1 ] TO SCHEDULE [2 ]
NUMBERS followed by SCHEDULE
COPY SCHEDULE
COPY SCHEDULE
destination schedule number field.
5. Press the SCHEDULE key to copy the schedule and exit the screen.
6. Press the
MENU key to return to the main menu. The contents of Weld Schedule 1 will be
copied to Weld Schedule 2, overwriting the previous contents of Weld Schedule 2.
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4. SYSTEM SECURITY
CHAPTER 3: USING PROGRAMMING FUNCTIONS
From the MAIN MENU, press the 4 key to go to up
SYSTEM SECURITY screen. With this screen,
you can protect the weld schedules from
unauthorized changes by programming the
Control with a user-defined protection code.
1. Schedule Lock
1. SCHEDULE LOCK : OFF
2. SYSTEM LOCK : OFF
3. CALIBRATION LOCK : OFF
NUMBERS Select, MENU Previous menu
<SYSTEM SECURITY>
This function prevents unauthorized users from selecting any weld schedule other than the displayed
schedule, and from changing any weld energy/time parameters within the weld schedule.
2. System Lock
This function prevents unauthorized users from changing any of the options on the main menu. It also
prevents unauthorized users from changing weld energy/time parameters within a weld schedule. This
security level allows you to select different schedules from the front panel.
3. Calibration Lock
This function prevents unauthorized users from modifying any of the calibration settings.
NOTE: All security options use the same procedure to enter a security code and to turn the security
code OFF.
1. Press the 1 key to select SCHEDULE
LOCK
. This will bring up the CHANGE
STATUS
screen, as shown at the right.
2. Enter a 7-digit number, from 0000001
to 9999999, in the code field, and then
enter a period. This will bring up the
SYSTEM SECURITY menu screen, this
PASSWORD :
NUMBERS for code followed by PERIOD
CHANGE STATUS>
– – – – – – –
time with SCHEDULE LOCK: ON.
With ON selected, all other weld schedules are locked out and cannot be modified or used for
welding.
3. To unlock the Control from security protection, return to the CHANGE STATUS screen and
enter the code that you entered in Step 2. This will bring up the SYSTEM SECURITY menu
screen, this time with SCHEDULE LOCK: OFF.
4. If you forget the security code and wish to unlock the Control from security protection:
• Return to the CHANGE STATUS screen.
• Enter a security code of 280.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
5. COMMUNICATION
The following menu screens tell you how to set the Control's communication and data options.
However, to enable the Control to perform these functions, you must install the software from the
optional DC25/UB25/HF25 Datacom Communications Interface Kit, commonly referred to as "the
Datacom kit” or Weldstat in a host computer. The Datacom Operator Manual describes cables,
connections, RS-232 operation, RS-485 operation, sample weld reports, data collection, and how to use
remote commands. The Datacom Kit 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).
Rear-mounted RS-232 and RS-485 connectors allow for remote programming, weld schedule selection,
and data logging for SPC purposes. Data output provides the necessary process documentation for
critical applications and permits data logging for SPC purposes.
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.
The Control contains internal software that gives you a great deal of flexibility in the setup and use of
your welding system. The Control software displays various menu screens on the LCD, each containing
prompts telling you which of the Control's front panel controls to use in order to customize operating
parameters, set the Control for use in an automated welding system, and program communication
settings for use with data-gathering devices such as a host computer.
The following menu screens tell you how to set the Control's communication and data options.
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.
1. Communication Role
1. From the
to go to the COMMUNICATION menu
(shown with default settings).
2. From the COMMUNICATION menu,
toggle the 1 key to select MASTER or
SLAVE. The COMMUNICATION ROLE
MAIN MENU, press the 5 key
COMMUNICATION
1. COMMUNICATION ROLE : SLAVE
2. I.D. NUMBER : 01
3. BAUD RATE : 9600
NUMBER Select, MENU Previous menu
line will now reflect your role selection.
• In the
MASTER role, the Control will:
− Send weld data to the host computer after each weld operation.
− Send text data to a serial printer, providing a printout of the average voltage and
current values for each weld, generating a "paper history" of welds performed.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
• In the SLAVE role, the Control will send weld data only when requested by the host
computer. For RS-485 installations with mulitple controls on one communications
channel, this role is preferred.
NOTE: For weld data collection and host computer control information, refer to the
Datacom Operator Manual, which describes how to use the
MASTER and SLAVE options.
3. Press
MENU to return to the MAIN MENU.
2. I.D. Number
The host computer may be used to talk with multiple Controls using a single RS-485 communications
line. Each Control sharing that line must have a unique identification number. To enter an identification
number for the Control, proceed as follows:
1. From the
to go to the
2. From the
screen, press the 2 key to get the I.D.
NUMBER
MAIN MENU, press the 5 key
COMMUNICATIONS MENU.
COMMUNICATIONS MENU
entry screen.
I.D. NUMBER
I.D. NUMBER : 01
NUMBER Change, MENU Previous menu
3. Enter a two-digit number, from 01 to 30, in the I.D. NUMBER field.
4. Press the MENU key to get the COMMUNICATION menu screen. This time the I.D. NUMBER
line will display your I.D. number entry.
5. Press MENU to return to the MAIN MENU.
3. Baud Rate
The baud rate at which the data is sent must match the baud rate of the host computer. To enter the baud
rate, proceed as follows:
1. From the
press the 3 key to get the BAUD RATE
selection screen.
2. Use the numeric keypad to select the
baud rate of the receiving device. The
display automatically returns to the
COMMUNICATION menu, which shows
COMMUNICATION menu,
BAUD RATE
1. 1200 6. 19.2K
2. 2400 7. 28.8K
3. 4800
4. 9600
4. 14.4K
NUMBER Change, MENU Previous menu
the new baud rate.
3. Press
MENU to return to the MAIN MENU.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
6. RELAY
1. From the MAIN MENU, press the 5 key
to go to the RELAY output state
selection menu, shown at the right. The
Control has two relays that can provide
dry-contact signal outputs under four
conditions.
See Appendix C, System Timing for the timing diagrams for the two relays.
2. From the
to go to
RELAY menu, press the 1 key
RELAY 1 shown at the right.
3. Press the 1 key to toggle the relay
contact signal state: ON (closed) or OFF
(open).
4. Press the 2 key to select the WHEN
menu, shown at the right.
5. Press the 4 key to select OUT OF LIMITS
as the condition for initiating the Relay
1 output signal. This will bring up the
RELAY 1 menu screen, where the WHEN
line will now reflect OUT OF LIMITS.
<RELAY>
1. RELAY 1 : ON WHEN ALARM
2. RELAY 2 : ON WHEN ALARM
NUMBER Select, MENU Previous menu
<RELAY 1>
1. SET RELAY TO : ON
2. WHEN : ALARM
NUMBER Select, MENU Previous menu
WHEN
1. WELD 6. P1 LOW LIMIT
2. END OF WELD 7. P2 HIGH LIMIT
3. ALARM 8. P2 LOW LIMIT
4. OUT OF LIMITS
5. P1 HIGH LIMIT
NUMBER Select, MENU Previous menu
6. Press the MENU key to return to the RELAY screen. The RELAY 1 line will now reflect your
selection: RELAY 1 ON WHEN OUT OF LIMITS.
7. CALIBRATION
With the main menu displayed, press the
go to the
CALIBRATION CAUTION screen, as
shown at the right. Only authorized personnel
should calibrate the Control. The calibration
procedure is given in Chapter 6, Calibration.
6 key to
< CALIBRATION CAUTION >
CALIBRATION SHOULD BE PERFORMED BY A
QUALIFIED TECHNICIAN ONLY.
REFER TO MANUAL FOR CALIBRATION SETUP.
W Next, Menu menu
HF25 DC RESISTANCE WELDING SYSTEM
3-6 990-333
8. RESET TO DEFAULTS
CHAPTER 3: USING PROGRAMMING FUNCTIONS
From the MAIN MENU, press the 7 key to go to
the RESET TO DEFAULTS menu, as shown at the
right. Through this menu, you may reset all
system programmed parameters and all weld
schedules to the original factory default settings
(see the table below).
1. RESET SYSTEM PARAMETERS
2. RESET ALL SCHEDULES
EPROM DATE: XX-XX-XX XX:XX VX.XX
NUMBER Select, MENU Previous menu
<RESET TO DEFAULTS>
Factory Default System Parameters
System Parameter Default Setting System Parameter Default Setting
Foot Switch Weld Abort ON End of Cycle Buzzer OFF
Switch Debounce Time 10 ms
Display Contrast 050% Relays 1 and 2 On When Alarm
Buzzer Loudness 050%
1. Reset System Parameters
1. With the reset to defaults screen
displayed, press the 1 key. This will
bring up the RESET SYSTEM
PARAMETERS
query menu, as shown at
the right.
1. NO
2. YES
NUMBER Select, MENU Previous menu
2. Press the 2 key to select YES. This will automatically reset the system to the factory and
return the screen to the RESET TO DEFAULTS display.
2. Reset All Schedules
1. Press the 2 key. This will
automatically reset all weld schedule
parameters to the factory defaults and
return the screen to the RESET TO
DEFAULTS
display.
2. Press the MENU key to return to the
MAIN MENU screen.
1. NO
2. YES
ALL WELD SCHEDULES ARE RESET
NUMBER Select, MENU Previous menu
<RESET ALL SCHEDULES?>
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
9. CHAIN SCHEDULES
This feature allows you to automatically change from any weld schedule to any other schedule after a
preset count, creating a "chain" of schedules that can accommodate a variety of welding needs. For
example:
• A single work piece requires four welds, two weld points require the same weld schedule, each
of the other two points require different weld schedules.
In this case you would program a sequence, or "chain," that looks like this: Schedule 01 [2
times] £ Schedule 02 [1 time] £ Schedule 03 [1 time] £ Schedule 01. This sequence
will repeat, or "loop," until you turn Chain Schedules OFF.
• Some applications require a lower current for a number of welds after the electrodes have been
replaced or resurfaced. Once the electrodes have been “seasoned”, the current can be increased
as required. If the electrodes require 100 welds to “season”, Schedule 01 can be programmed
with a lower current and Schedule 02 can be programmed with a higher current. The chain
would look like this: Schedule 01 [100 times] £ Schedule 02 [1 time] £ Schedule 02 [1
time].
In this chain, Schedule 02 will just keep repeating after the 100 welds made using Schedule 01.
When the electrodes are replaced or resurfaced, you can manually switch back to Schedule 01
to restart the sequence.
You can program any of the Control's 99 stored schedules to chain to any other schedule, or back to
itself as in the second example above. The chain code becomes part of each weld schedule. You can
turn the Chain Schedules feature ON or OFF, or re-program chains, any time you want.
1 From the MAIN MENU, press the 8 key
to go to the CHAIN SCHEDULES menu.
NOTE: You should program, or
"setup," the chain of schedules you
want before you turn this feature ON.
1. CHAIN SCHEDULE :OFF
2. SETUP CHAIN SCHEDULES
NUMBER Select, MENU Previous menu
CHAIN SCHEDULES
2 Press the 1 key to toggle CHAIN SCHEDULES ON or OFF.
3 From the CHAIN SCHEDULES menu,
press the
SCHEDULE SETUP
2 key to go to the CHAIN
menu.
SCHEDULE NUMBER WELD COUNT NEXT
Ø1 ØØØ1 Ø1
Ø2 ØØØ1 Ø2
Ø3 ØØØ1 Ø3
Ø4 ØØØ1 Ø4
VW scroll, SCHEDULE select, MENU menu
CHAIN SCHEDULE SETUP
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
4 Use the (Up/Down) keys on the
front panel to scroll vertically through
the schedules to highlight the weld
count for the schedule you want to
chain.
5 Use the numeric keypad to enter the
number of times you want this schedule
to weld before going to the next
schedule.
6 Use the
SCHEDULE key to move the
highlight horizontally to select
7 Use the numeric keypad to enter the
number of the next schedule in the chain.
8 Use the SCHEDULE key to move the
highlight horizontally back to the WELD
COUNT
column. Repeat Steps 4 through
8 to program the rest of the chain.
NEXT.
CHAIN SCHEDULE SETUP
SCHEDULE NUMBER WELD COUNT NEXT
Ø4 ØØØ1 Ø4
Ø5 ØØØ1 Ø5
Ø6 ØØØ1 Ø6
Ø7 ØØØ1 Ø7
VW scroll, SCHEDULE select, MENU menu
CHAIN SCHEDULE SETUP
SCHEDULE NUMBER WELD COUNT NEXT
Ø4 ØØØ1 Ø4
Ø5 ØØØ2 Ø5
Ø6 ØØØ1 Ø6
Ø7 ØØØ1 Ø7
VW scroll, SCHEDULE select, MENU menu
CHAIN SCHEDULE SETUP
SCHEDULE NUMBER WELD COUNT NEXT
Ø4 ØØØ1 Ø4
Ø5 ØØØ2 Ø5
Ø6 ØØØ1 Ø6
Ø7 ØØØ1 Ø7
VW scroll, SCHEDULE select, MENU menu
9 When you finish programming the chain, press the MENU key to return to the CHAIN
SCHEDULES
menu.
10 Press the 1 key to toggle between ON or OFF.
11 Press the RUN key on the front panel, then use the keys to select the first weld schedule in
the chain you want to use. The Control will now weld in the "chain" mode until you turn the
Chain Schedules feature OFF.
NOTE: When Chain Schedules is turned ON, the LCD screen changes to show the chain
information on the right side of the screen.
Below the current schedule number, you can see the number of times the current schedule will
be repeated, and the number of the next schedule in the chain.
HF25 DC RESISTANCE WELDING SYSTEM
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
SETUP 1
1. Footswitch Weld Abort
From the SETUP 1 screen, press the 1 key to toggle between ON and OFF. This function controls how
the Control interfaces with a foot switch, a force firing switch, or a programmable logic control (PLC).
Any of these switches could be the weld initiation switch in your system setup.
ON means that the welding process is initiated by closure of the initiation switch and continues to its
conclusion while the initiation switch remains closed. If the initiation switch opens during the welding
process, the welding process will terminate. The ON state is preferred for human operated welding
stations since it allows you to abort the weld process by releasing the foot switch (or the foot pedal in the
case of a manually actuated weld head).
OFF is preferred for computer or PLC controlled welding stations since a single start pulse can be used
to initiate the welding process. To select the
ABORT
line will now reflect your selection.
2. Switch Debounce Time
The contacts of single pole mechanical firing switches “bounce” when they close. The switch debounce time function allows you to specify that the initiation switch contacts must remain closed for 10,
20, or 30 milliseconds before the weld period can be initiated, thereby avoiding false starts caused by the
switch contact bouncing.
ON/OFF states, press the 1 key. The FOOTSWITCH WELD
1. From the SETUP 1 screen, press the 2
key to go to the SWITCH DE-BOUNCE
TIME
menu screen.
2. Select the required debounce time by
pressing the 1, 2, 3 or 4 key. NONE
represents a debounce time of 0 ms.
Use NONE for interfacing with the Unitek Peco Model 350C Electronic Weld Force Control.
3. Press the
MENU key to return to the SETUP 1 screen. The SWITCH DEBOUNCE TIME line
will now reflect your switch debounce time selection.
<SWITCH DEBOUNCE TIME>
1. NONE
2. 10 ms
3. 20 ms
4. 30 ms
NUMBER Select, MENU Previous menu
HF25 DC RESISTANCE WELDING SYSTEM
3-10 990-333
CHAPTER 3: USING PROGRAMMING FUNCTIONS
3. Firing Switch
With the SETUP 1 screen displayed, press the 3 key to select this function. The firing switch input, in
conjunction with or without inputs from the foot switch input, initiates the weld energy sequence. Select
the required switch type by pressing the
the display to the
SETUP 1 screen.
1, 2, or 3 key. Pressing the numeric keys automatically returns
1. Auto
The Control accepts a single pole, double pole or
optical firing switch input from a Unitek Peco
weld head. Firing switch activation indicates
that the weld head has reached the set weld
force, thus permitting the weld energy sequence
1. AUTO
2. NONE
3. REMOTE
NUMBER Select, MENU Previous menu
<FIRING SWITCH>
to start.
2. None
When using a non-force fired weld head, weld energy initiation must be supplied with the foot switch
input. Additionally, you must select sufficient squeeze time to permit the weld force to stabilize after
contacting the weld pieces.
3. Remote
Use this setting in an automation application or when using PLC control. The BCD input lines, via the
CONTROL SIGNALS connector (see Appendix B. Electrical and Data Connections), select weld energy
schedules and initiate the weld energy sequence.
4. Input Switch Select
This function selects the type of external switch to be used by the firing switch, foot switch, emergency
stop, and process inhibit inputs; and how these switches are activated.
NOTE: Before selecting any of these options, connect all desired closed input switches to the Control.
Otherwise an input switch alarm will occur.
1. From the
key.
2. Select the required switch type by
pressing the
numeric keys automatically returns the
display to the
SETUP 1 screen, press the 4
1, 2, or 3 key. Pressing the
SETUP 1 screen.
<INPUT SWITCH SELECT>
1. MECHANICAL
2. OPTO
3. PLC
NUMBER Select, MENU Previous menu
The FIRING SWITCH option will now reflect your switch type selection.
1. MECHANICAL: Accepts dry contact, single or double pole switch or read relay devices.
2. OPTO: Accepts opto coupler switch for eliminating switch debounce problems.
3. PLC: Accepts +24 VDC from a PLC as a source for activating the Control inputs.
NOTE: For detailed electrical interface information on these input switch selections, see
Appendix B. Electrical and Data Connections.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
1. MECHANICAL
1. With the INPUT SWITCH SELECT screen
displayed, press 1 to display the
MECHANICAL switch select menu.
2. Select the required switch type by pressing
the
1, or 2 key. Pressing the numeric keys
automatically returns the display to the
SETUP 1 screen.
• MECHANICAL SWITCH NORMAL OPEN. Initiate the Control by closing the mechanical
switches.
• MECHANICAL SWITCH NORMAL CLOSED. Initiate the Control by opening the mechanical
switches.
2. OPTO
1. With the INPUT SWITCH SELECT screen
displayed, press 2 to display the OPTO
switch select menu.
2. Select the required switch type by
pressing the 1, or 2 key. Pressing the
numeric keys automatically returns the
display to the SETUP 1 screen.
<INPUT SWITCH SELECT>
1. MECHANICAL SWITCH NORMAL OPEN
2. MECHANICAL SWITCH NORMAL CLOSED
NUMBER Select, MENU Previous menu
<INPUT SWITCH SELECT>
1. OPTO COLLECTOR NORMAL OPEN
2. OPTO COLLECTOR NORMAL CLOSED
NUMBER Select, MENU Previous menu
• OPTO COLLECTOR NORMAL OPEN. Turn the open collector output transistor of the opto
isolator to ON to initiate the Control.
• OPTO COLLECTOR NORMAL CLOSED. Turn the open collector output transistor of the
opto isolator to OFF to initiate the Control.
3. PLC
1. From the INPUT SWITCH SELECT
screen, press the 3 key to display the
PLC select menu.
2. Press the
1 or 2 key to select how the
input opto switches will initiate the
Control. Pressing the numeric keys
automatically returns to the
screen.
• PLC 0VDC TURN ON. Initiate the Control from a PLC source by changing the PLC voltage
from +24 VDC to 0 VDC.
• PLC +24VDC TURN ON. Initiate the Control from a PLC source by changing the PLC
voltage from 0 VDC to +24 VDC.
SETUP 1
<INPUT SWITCH SELECT>
1. PLC 0VDC TURN ON
2. PLC +24VDC TURN ON
NUMBER Select, MENU Previous menu
HF25 DC RESISTANCE WELDING SYSTEM
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
5. CONTROL SIGNALS SELECT
From the SETUP 1 screen, press the 5 key to access the CONTROL SIGNALS SELECT menu screen. This
function selects the type of external input switch to be used by the control signals input and how these
switches are activated. For a complete description of the control signals, see Appendix B, Electrical and
Data Connections.
Setup 2
1. Display Contrast
1. From the SETUP 1 screen, press the 1
key to go to the DISPLAY CONTRAST
adjustment screen.
2. Use the V and W keys to adjust the
screen contrast for comfortable viewing
in the shop environment.
3. Press the MENU key to return to the SETUP 1 screen.
2. Buzzer Loudness
1. From the SETUP 1 screen, press the 2
key to go to the BUZZER LOUDNESS
adjustment screen.
2. Use the V and W keys to adjust the
buzzer tone so that it can be heard
against shop background noise.
3. Press the MENU key to return to the SETUP 1 screen.
3. End Of Cycle Buzzer
<DISPLAY CONTRAST >
DISPLAY CONTRAST : 50 %
0 10 20 30 40 50 60 70 80 90
Adjust , Page, Graph or Data
<BUZZER LOUDNESS >
DISPLAY CONTRAST : 50 %
0 10 20 30 40 50 60 70 80 90
Adjust , Page, Graph or Data
1. With the SETUP 1 screen displayed, press the 3 key to toggle the end of cycle buzzer ON or
OFF. This function is normally used with manually actuated weld heads. ON means that an
audible signal will be given at the end of each weld process to signal you to release the foot
pedal.
2. To select the
ON/OFF states, toggle the 3 key. The END OF CYCLE BUZZER line will now
reflect your state selection.
HF25 DC RESISTANCE WELDING SYSTEM
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
4. Update Graph After Weld
From the SETUP 1 screen, press the 4 key to toggle the update graph after weld ON or OFF function.
The UPDATE GRAPH AFTER WELD line will now reflect your state selection.
ON means that the actual weld energy profile will overlay the programmed weld profile after each
weld is made. The weld graph is useful for detecting weld splash, which is indicated by vertical
gaps in the overlap. You can reduce weld splash, and eliminate it in some cases, by using the
upslope weld energy profile.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
Section II. Operational States
The Control has seven operational states:
NO WELD WELD MENU MONITOR
TEST ALARM RUN
You go to the NO WELD, MENU, TEST, RUN and MONITOR states through the control panel. The WELD
and ALARM states are functions of the force firing switch and foot switch input states.
No Weld State
Setting the WELD/NO WELD switch on the control panel to the NO WELD position inhibits the delivery of
weld energy if a weld is initiated, and will display a WELD SWITCH IN NO WELD POSITION alarm on the
screen. But the Control will still go through its electronic weld cycles as programmed into the selected
weld schedule. Use the no weld state when adjusting the air regulators on air actuated weld heads.
Menu State
Pressing the MENU key puts the Control in the
menu state. It brings up menu screens that
enable you to select various options common to
all weld schedules, such as how the Control
interfaces with the force firing switch, foot
switch and weld head.
Test State
Pressing the V key, or changing the voltage or
time settings while in the voltage feedback
welding mode, puts the Control in the test state.
After making one weld, the Control internally
optimizes the feedback control loop to produce
the fastest rise time, minimum overshoot weld
pulse. The test state is automatically replaced by
the run state for subsequent welds.
MAIN MENU
1. SETUP 5. RELAY
2. WELD COUNTER 6 CALIBRATION
3. COPY A SCHEDULE 7. SESET TO DEFAULTS
4. SYSTEM SECURITY 8. RESET TO DEFAULTS
9. CHAIN SCHEDULES
NUMBER Select an item
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
Run State
Pressing the RUN key puts the Control in the run
state. In the run state, the screen shows a trace
that represents your programmed parameters for
a given weld schedule. You may select a
different weld schedule to be programmed with
the SCHEDULE key and keypad, or with the up
and down arrows. Then, you may program
squeeze time, up slope, weld time, weld energy,
down slope and cool time with the trace segment selector keys.
The top line of text is showing (in the order displayed) that the Control is in the run state, the voltage at
the voltage sense lead connections for the PULSE 1 weld period is 1.012 volts, the energy limits monitor
is set for monitoring peak voltage (rather than average voltage), the voltage at the voltage sense input
connection for the PULSE 2 weld period is 1.014 volts, and the total weld count since the weld counter
was last reset is 5,237.
The weld profile trace is an analog display of the
electrical parameters programmed with the weld
period selector keys. When the weld is initiated,
a profile of the actual weld energy delivered
during the weld cycle, or both weld cycles, will
be overlaid on the trace.
The large-type number 02 is the selected weld
schedule.
The values 0.050kA and 0.060kA below the trace are respectively the weld current values programmed
for PULSE 1 and PULSE 2 weld periods. You may optionally program weld energy in volts or kilowatts
with the energy units selection keys.
Use the time/energy selector keys to toggle between the weld energy value field and the bottom line of
text, which is the weld period time selection field. Use the weld period selector keys to enable the weld
periods for programming, and use the numeric pad keys for entering time values.
See Section IV, Using HF28 Welding and Monitoring Functions for application-related descriptions of
the weld schedule profile.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
Weld State
Once weld current is flowing, the Control is in the WELD state. You can terminate weld current in five
ways:
• Remove the first level of a single-level foot switch, assuming weld abort is ON.
• Remove the second-level of a two-level foot switch, assuming weld abort is ON.
• Input the process stop signal (refer to Appendix B, Electrical and Data Connections).
• Open the normally closed switch across the operator emergency stop switch cable.
NOTE: This action removes all power from the Control.
• Through the action of the monitor settings.
Completion of the firing state is indicated by a profile of actual delivered weld energy superimposed on
the programmed weld energy trace, as shown in the example above.
Monitor State
From the MONITOR keys section on the front
panel, press the kA, V, kW or Ω key to go to the
monitor state. In this state, when the Control
detects an out of limits condition, it will take one
of four actions, depending on the selection made
with the
Also, an alarm message will be displayed and any relay set for ALARM or OUT OF LIMITS will be
energized.
MONITOR display, as shown at the right.
The selections are:
• NONE: The weld cycle will continue.
• STOP DURING PULSE 1: The weld cycle will stop immediately. Pulse 2 (if applicable) will not
fire.
• INHIBIT 2ND PULSE: During the COOL time, the Control calculates the average of the Weld1
pulse (including upslope, weld and downslope). If the average of the Weld1 pulse is out of
limits, the weld cycle will stop and the Weld2 pulse will be inhibited.
APC: STOP PULSE 1/ALLOW PULSE 2 stops Pulse 1 immediately after upper or lower energy
•
limits are exceeded, but allows Pulse 2 to fire.
The display shows the actual trace of the weld current, voltage or power, and either the peak or the
average value for each weld pulse as selected by pressing the
PEAK/AVERAGE key.
See Section IV, Using HF28 Welding and Monitoring Functions for a detailed description of energy
limits monitor operation.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
Alarm State
The Control automatically recognizes many
alarm conditions. The example WELD SWITCH
IN NO WELD POSITION
the right is displayed when you attempt to
initiate a weld with the WELD/ NO WELD switch
in the NO WELD position.
alarm screen shown at
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
Section III. Weld Functions
Welding Applications
Most welding applications require the use of
specialized weld functions. A weld function is a
unique heat profile created by weld current,
voltage, or power that is applied over a fixed
time period, to resistance weld different parts.
An example of a fully programmed weld profile
is shown at the right.
Applications include parts that:
• Are plated with cadmium, tin, zinc, or nickel
• Have heavy oxide coatings such as aluminum
• Are round or not flat
By programming the appropriate weld period time and weld energy amplitudes for the weld period
segments, you can program an appropriate weld schedule profile to perform the above applications.
Typical applications and recommended weld schedule profiles are defined in the table below. For more
information about resistance welding, see Appendix D, The Basics Of Resistance Welding and Appendix
E, Quality Resistance Welding Solutions, Defining The Optimum Process
Welding Applications
Run
Squeeze
Up1
Up
State
0-999ms
Down
0-9.9ms
Weld 1
0-9.9ms
Weld current
Down 1
0-9.9ms
Weld head position
Cool
0-9.9ms
Up2
0-9.9ms
Weld 2
0-9.9ms
Weld current
Down 2
0-9.9ms
Hold
0-999ms
Run
State
Up
Weld Function Typical Application
Basic Weld Make single spot welds on simple flat parts without plating, or on conductive parts such as
those made of copper or brass.
Quench/Temper Spot-weld flat or round parts that have minimum plating thickness.
Up/Downslope Weld round parts, parts that are not flat, spring steel parts, or heavily plated or oxidized parts
such as aluminum.
Dual Pulse Use for best control of miniature and small parts spot welding with or without plating.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
Weld Head Applicability
The weld functions can be used with Unitek Peco force fired, manual weld heads; air actuated weld
heads; or Series 300 Electronic Force Controlled Weld Heads. For manually actuated weld heads and
the Series 300 Weld Heads, weld current begins when the force-firing switch closes. For force fired, air
actuated weld heads, weld current begins when both levels of a two-level foot switch are closed and the
force firing switch in the air actuated weld head closes.
When the weld functions are used with a non-force fired, air actuated weld head, the squeeze period
must be used to allow sufficient time for the electrodes to close and apply the required weld force to the
parts before the weld period begins. Weld current begins when the squeeze period ends.
When the weld functions are used with any type of air actuated weld head, the hold period can be used
to automatically keep the electrodes closed on the parts after weld current has terminated to provide
additional heat sinking or parts cooling.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
Section IV: Using Weld and Monitor Functions
Overview
To ensure accurate, consistent welds, the Control delivers extremely precise pulses of energy to the weld
head. Each pulse is comprised of weld-time and weld-energy (voltage, current, or power) values preprogrammed by the user. The Control is a closed-loop welding control using internal and external
sensors to measure the weld-energy delivered to the weld head. Weld-energy feedback instantly goes to
the Control's logic circuits that actively correct the pulse to compensate for any variation in part
resistance. The Control also has several monitor functions that give you remarkable control over the
welding and production process. Together, these features ensure precise, consistent welds, higher
productivity, a lower rejection rate, and longer electrode life.
Before operating the Control, it is important to know how to match the Control's capabilities to specific
weld applications. This chapter provides Weld, Feedback, and Monitor details in the following
sections:
• Weld Schedules
− Single-Pulse
− Upslope/Downslope
− Dual-Pulse
• Programmable Feedback Modes
• Weld Monitor
− Active Part Conditioner
− Energy Limits
− Pre-Weld Check
Chapter 4, Operating Instructions, contains the step-by-step instructions on how to program each of the
functions above.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
Weld Schedule Definition
Weld Schedule is the name given to each of 31 separate weld profiles stored in the Control, numbered
from 01 £ 31. A weld profile is the graphic representation [or waveform] of the numeric weld-time
and weld-energy values. NOTE: There is an additional weld schedule numbered 00, which can be used
as a "scratch pad" to develop new weld schedules.
When time and energy values are entered using the numeric keypad, the Control displays a line-graph of
the weld profile on the LCD screen. You can see the graph change as you enter new time and energy
values.
Weld profiles may be programmed for single-pulse, upslope/downslope, or dual-pulse operation.
Weld schedules may also use special monitoring features of the Control such as Energy Limit, Active
Part Conditioner, and Pre-Weld Check. These features are described later in this chapter.
Weld Sequence Timing
A weld schedule is a unique heat profile programmed in constant current, voltage, or power that is
applied over a fixed time period, to resistance weld different parts. The entire weld can include all of
the following time periods: Squeeze Time, Upslope 1, Weld Pulse 1, Downslope 1, Cool Time, Upslope
2, Weld Pulse 2, Downslope 2, and Hold Time. The sample dual-pulse profile [or waveform] below
shows the weld current and the corresponding position of the weld head. The graph labeled WELD
CURRENT
is what displays on the LCD when you schedule a weld profile.
Sample Weld Sequence (Dual-Pulse)
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Welding Applications
Weld Pulse Profile Typical Application
CHAPTER 3: USING PROGRAMMING FUNCTIONS
Single-Pulse
Upslope/Downslope
Dual-Pulse
Can be used for many of spot-welding applications. Use on flat parts
without plating, or on conductive parts such as those made of copper or
brass.
Upslope/Downslope should be used for the majority of spot welding
applications. Weld round parts, parts that are not flat, spring steel parts,
or heavily plated or oxidized parts.
Use for spot welding parts with plating. First pulse can be used to
displace plating or oxides and the second pulse to achieve the weld.
For a detailed coverage of resistance welding theory, please refer to Appendix D, The Basics of
Resistance Welding.
Single-Pulse Weld Profile
Applications
• Flat parts that do not have any plating or heavy oxides. Conductive parts made of copper
or brass.
Description
Single-Pulse is a term used by the industry to describe the simplest heat profile used for many
resistance spot-welding applications.
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Single-Pulse Weld Profile
CHAPTER 3: USING PROGRAMMING FUNCTIONS
Upslope/Downslope Weld Profile
Applications
• Round or non-flat parts and most resistive materials.
Description
Upslope allows a gradual application of weld energy which permits the parts to come into better
contact with each other reducing the electrode to part contact resistances. Upslope can allow a
smaller electrode force to be used, resulting in a cleaner appearance by reducing electrode
indentation, material pickup and electrode deformation. It can also be used to displace plating
and/or oxides, reduce flashing and spitting, or reduce thermal shock when welding parts containing
glass-to-metal seals.
Downslope (annealing) assists in the grain refinement of certain heat-treatable steels, and prevents
cracking in aluminum and other materials by reducing the cooling rate. Annealing is not typically
used for welding small parts.
Upslope / Downslope Weld Profile
Dual-Pulse Weld Profile
Applications
• Flat-to-flat parts.
• Round-to-round parts.
• Round-to-flat small parts that may or may not be plated.
Description
Adding upslope to the front of both weld periods allows a reduction in electrode force, this results
in a cleaner appearance by reducing electrode indentation, material pickup and electrode
deformation.
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Upslope will also help to displace plating and/or oxides, reduce flashing and spitting, or reduce
thermal shock when welding parts containing glass-to-metal seals. In the normal application of
dual-pulse, the Pulse 1 weld period provides sufficient heat to displace the plating or oxides, seat
the electrodes against the base metals, and force the parts into intimate contact. The cool period
allows time to dissipate the heat generated during Pulse 1.
The Pulse 2 weld period completes the structural weld. The Pulse 2 weld current is typically greater
than the Pulse 1 weld current by a factor of 3 as the first pulse significantly reduces the resistance of
the interface between the parts. The only use for the downslope period following the Pulse 1 or
Pulse weld period is to control grain refinement in brittle parts by slowly reducing the weld current
to zero during the downslope period.
The dual-pulse weld profile is very valuable for pre-checking gross parts positioning problems and
reducing parts scrap. Use the Pulse 1 weld at 0.050 kA [or less] and 2.0 ms as a pre-check pulse.
Experiment with upper and lower limit values that you can use to inhibit the Pulse 2 weld if the test
conditions measured by the Pulse 1 weld are out of limits.
NOTE: Upslope is required when a lower limit value is programmed.
CHAPTER 3: USING PROGRAMMING FUNCTIONS
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
Section V. Programmable Feedback Modes
Introduction
The feedback mode (current, voltage, power) is one of the selections entered when programming a
weld schedule. Programming weld schedules is explained in chapter 4, Operating Instructions.
Current Mode
Application
• Flat parts where the part-to-part and electrode-to-part contact is controlled and
consistent
Description
This mode delivers the programmed current regardless of work piece resistance changes. This
compensates for slight changes in part thickness without affecting weld quality. Set monitoring
limits on voltage.
Voltage Mode
Application
• Ideal for welding round or non-flat parts
Description
This mode controls the voltage across the work piece during welding. It helps to compensate for
part misplacement and force problems and automatically reduces weld splash, which is often
associated with non-flat parts and wire welds. Set monitoring limits on current.
Power Mode
Application
• Breaking through surface oxides and plating
• Automated applications where part or electrode surface conditions can vary over time.
Description
This mode precisely varies the weld current and voltage to supply consistent weld energy to the
parts. The power mode has been shown to extend electrode life in automated applications. Set
monitoring limits on current or voltage.
NOTE: In a Dual-Pulse weld profile, a different feedback mode can be used for each pulse. For
example, a constant power first pulse can be used to break through plating in combination with a
constant current second (welding) pulse.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
Section VI. Weld Monitor
Introduction
The Control's feedback sensors not only control weld energy output, but they can also be used to
monitor each weld. The Control's monitor features allow you to view graphic representations of welds,
visually compare programmed welds to actual welds, look at peak or average energy values, set upper
and lower limits for welds, and make use of these features:
• Active Part Conditioner (APC)
• Energy Limits
• Pre-Weld Check
Active Part Conditioner (APC)
Application
• Displace surface oxides and contamination
• Reduce contact resistances before delivering the main weld energy.
Description
In the production environment, it is common to see large variations in:
• Oxide and contamination
• Plating thickness and consistency
• Shape and fit up
• Contact resistances due to varying part fit up
In order for a weld to occur, the surface oxides and contamination must be displaced to allow proper
current flow through the parts. Levels of oxide and contamination vary from part to part over time,
which can have an adverse effect on the consistency of the welding process. If production parts are
plated, there can also be a plating process variation over time resulting in inconsistent welds. These
minor material variations are a major cause of process instability, and it is best welding practice to
seek to minimize their effect.
Active Part Conditioner is designed to cope with material contamination, variation and can be
programmed to apply the exact power to the parts required to displace oxide or contaminants. In
addition, the “Part Conditioner” pulse will terminate at a precise current flow preventing the sudden
high flow, which occurs when the oxide is displaced. This prevents weld splash and material
expulsion, which occurs as a result of an excessively fast heating rate. Part conditioning can help to
reduce variations in contact resistance from part to part caused by different fit up of parts. It will
stabilize the contact resistances before the main welding pulse, therefore reducing variation from
weld to weld.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
How It Works
Both constant current feedback and constant voltage feedback modes are limited in their ability
to deal with varying levels of part contamination and oxide. If constant current feedback were
used, the power supply would ramp the voltage to very high levels in order to achieve current flow
through the oxide. This rapid input of current is likely to cause splash, especially with round parts.
Constant voltage mode is not ideal for this purpose either, as the voltage will be restricted from
reaching sufficient levels to break down the oxide.
Constant power is ideal for this purpose. As the power supply tries to achieve constant power to
the weld, it raises the voltage to high levels early in the output waveform, since current cannot flow
due to the oxide. As the high voltage breaks down the oxide layer, more current flows to the weld
and the voltage and resistance drop. It will achieve this in a controlled fashion to maintain constant
power to the weld.
Constant Power Waveform With Corresponding
Voltage And Current Waveforms
Active Part Conditioning uses a dual-pulse output. The first pulse is programmed for constant
power, and the second for either constant current, constant voltage, or constant power.
(Constant voltage is used if there is still a chance of weld splash). The purpose of a dual-pulse
operation is to enable the first pulse to target displacement of oxides and good fit up; the second
pulse achieves the weld.
Active Part Conditioning Waveform
The use of a current limit monitor for the first pulse enables the pulse to be terminated when a
predetermined amount of current flow is achieved. The rise of the current waveform is proof
positive that the oxide is breaking down and the parts are fitting up together, ready to weld. The
first pulse, therefore, should be programmed to be much longer than generally required. The power
supply will terminate the pulse based on the reading of current in the power supply’s monitor.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
Energy Limits
Applications
• Part-to-part positioning problems
• Electrode-to-part positioning problems
• Parts with narrow weld window
Energy Limits can be used in two different ways:
• To detect work piece resistance changes that occur when parts are positioned incorrectly at the
weld head. In this case, the energy limits will prevent blowouts, parts damage, and electrode
damage. Limits can be set to terminate the weld if this occurs.
• To stop the weld when a sufficient current, voltage, or power level is reached. Using limits in
this way ensures a more consistent input of energy, which produces consistently good welds.
Description
This function terminates the weld energy during the welding process if pre-set weld current,
voltage, or power limits are exceeded. In addition to inhibiting the weld, the Control has four
programmable relay outputs which can be used to trigger alarms to signal operators of weld faults,
or signal automation equipment to perform pre-programmed actions, such as stopping the
production line so the faulty weld piece can be removed.
The monitor measures the weld energy parameters during the weld period and compares the
measurements against the programmed limits. If any of the programmed limits are exceeded, the
energy limits monitor sets the Control to a state selected from the OUT OF LIMITS ACTION menu. In
addition, the Control's relays can be programmed to trigger alarms, or trigger an action in an
automated welding system.
NOTE: When using the energy limits monitor, always select a monitor mode that is different from
the feedback mode. For example:
• If you are welding in constant current, monitor voltage.
• If you are welding in constant voltage, monitor current.
• If you are welding in constant power, monitor current or voltage.
Example 1: Energy Limit Weld Termination
Example #1: In the profile above, the weld current is exceeding the selected upper limit before the
end of the welding cycle. The spike in the current waveform indicates that parts were misplaced.
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CHAPTER 3: USING PROGRAMMING FUNCTIONS
In this case, the operator has selected the option to terminate the weld energy under this condition,
so the energy limits monitor terminates the Pulse 1 weld and inhibits the Pulse 2 weld if it had been
programmed.
Example 2: Sufficient Current Level
Example #2: In the profile above, the weld current limit is at a sufficient level to get a good weld.
Pre-Weld Check
Application
• Detect Misaligned or Missing parts.
Function
This is used to see if parts are misaligned or missing before a welding pulse is delivered to the weld
head. If a part is missing or misaligned, you do not want the machine to weld because the result
would be an unacceptable weld and/or damaged electrodes.
Pre-Weld Check is similar to Energy Limits, however in this case Pulse 1 should be very short
(1-2 milliseconds), and the current should be low, about 10% of the Pulse 2 current. Pulse 1 should
be used as a measurement pulse and should not perform a weld.
Pre-Weld Check Waveform
Example: To detect misaligned parts, use constant current and set upper and lower voltage limits
for Pulse 1 If parts are misaligned, the work piece resistance will be higher, so the voltage will be
higher. If parts are missing, voltage will be lower. In either case, the Pulse 1 upper or lower limits
will be exceeded, and Pulse 1 can be inhibited.
NOTE: You must have upslope programmed into the pulse in order to set a lower limit.
In addition to inhibiting the weld, the Control has four programmable relay outputs, which can be
used to trigger alarms to signal operators of weld faults or signal automation equipment to perform
pre-programmed actions, such as stopping the assembly line so the faulty weld piece can be
removed.
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CHAPTER 4
OPERATING INSTRUCTIONS
Section I: Before You Start
This Chapter tells you how to turn the Control ON, use menu screens to customize operating parameters,
match the Control to your welding system, and how to operate the Control. This chapter is divided into
the following sections:
• Initial Setup
• Programming Weld Schedules (Quick Start)
− Single Pulse
− Upslope/Downslope
− Dual-Pulse
• Programming The Weld Monitor
• Programming For Active Part Conditioning
• Operation
Before operating the Control, you must be familiar with the following:
• The location and function of Controls and Indicators. For more information, see Chapter 1 of
this manual.
• How to select and use the Control functions for your specific welding applications. For more
information, see Chapter III, Using Programming Functions.
• The principles of resistance welding and the use of programmed weld schedules. For more
information, see Appendix F, The Basics of Resistance Welding. For additional information on
the welding process, see Appendix G, Quality Resistance Welding Solutions, Defining the
Optimum Process.
• If you are using the Optional LVDT, read Appendix D, LVDT Option to become familiar with
LVDT capabilities, calibration, and procedures. In order to use the LVDT capabilities, you
must perform the Operating Instructions in Appendix D in addition to the instructions in this
chapter.
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CHAPTER 4. OPERATING INSTRUCTIONS
Initial Setup: Pre-Operational Checks
Always perform these checks before attempting to operate the Control.
Connections
Verify that the Control has been connected to a manual or air-actuated weld head as described in
Chapter 2 of this manual. Verify that the Emergency Stop Switch shorting wires are connected or
verify that an Emergency Stop Switch is connected properly.
Power
Verify that power is connected as described in Chapter 2 of this manual.
Compressed Air
If you are using an air-actuated weld head, verify that compressed air is connected as described in
the appropriate sections of your weld head manual. Turn the compressed air ON, and adjust it
according to the instructions in your weld head manual.
Initial Setup Instructions
1. Adjust the weld head force adjustment knob for a force appropriate for your welding
application. A good starting point is the mid-point in the range of the weld head force.
2. Set the WELD/NO WELD switch on the Control front panel to the NO WELD position. In this
position, the Control will operate the weld head without producing weld energy.
a. NOTE: When you are ready to perform a weld, be sure to set this switch back to the
WELD position.
3. Turn the ON/OFF switch on the rear panel of the Control to the ON position. The default RUN
screen will be displayed. You will use this screen to enter welding parameters.
Default RUN Screen
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CHAPTER 4. OPERATING INSTRUCTIONS
Section II. Programming Weld Schedules
Introduction
The Control comes with 99 factory-installed
weld schedules, numbered from 01 through 99.
Each schedule looks like the display on the right.
See Section III, Using HF25 Welding And
Monitoring Functions for descriptions of the
features available in weld schedules.
The process of Programming a weld schedule consists of:
• Select a weld schedule.
• Enter new values in the selected schedule.
NOTE: For reference and convenience, you might want to keep a written list of your programmed weld
schedule values using the two-digit weld schedule number.
Select A Weld Schedule
1. To select weld schedules, first make sure that the RUN state is displayed on the LCD. If
not, press the RUN key on the front of the Control.
2. Press the SCHEDULE key on the right of the Control.
3. Use either of the methods below to select a schedule:
• Use the VW (Up/Down) keys to scroll through the list.
OR
• Use the numeric keypad to enter the two-digit number of the schedule you want.
Enter New Values
Some welding applications require no more than a simple weld schedule, programmed for SinglePulse, Upslope/Downslope, or Dual-Pulse operation. For other applications, you may want to use
the Energy Limits Monitor or Active Part Conditioning features of the Control. To enter new
values, follow the instructions for Single-Pulse, Upslope/Downslope, or Dual-Pulse weld schedules
on the following pages.
NOTE: If drastically different energy values are entered for Pulse 1 and Pulse 2, the Control will
require a minimum of 0.5 ms Cool Time. If different feedback modes are programmed for a dual
pulse weld, the Control will require a minimum of 0.5 ms Cool Time. If a Cool Time is set lower
than 0.5 ms, but not zero, the Control will default to 0.5 ms Cool Time.
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CHAPTER 4. OPERATING INSTRUCTIONS
Single-Pulse Weld Schedule
NOTE: If you are using the optional LVDT, you must perform the procedures described in Appendix
D, LVDT Option, Section 4, Operating Instructions in addition to the procedures below.
1.
Press the SCHEDULE key, then select a Weld Schedule using either the VW arrows or
the numeric keypad.
2.
Press the
SQUEEZE key to enter the squeeze time before the weld. Use the numeric
keypad to enter the time or use the VW arrows. Enter a time between 0 and 999
milliseconds. NOTE: We recommend 150 milliseconds.
3.
Press the PULSE 1 UPSLOPE key to enter the amount of time for the Weld Pulse 1
upslope. Use the numeric keypad to enter the time or use the VW arrows. Enter 0
milliseconds.
4. Press the PULSE 1 WELD key to highlight the bottom line of the LCD to enter the weld
time. Use the numeric keypad to enter the time or use the VW arrows. Enter a time
between 0 and 99 milliseconds.
5. Press the PULSE 1 WELD key again to highlight the middle line of the LCD to enter
weld energy. Use the numeric keypad to enter the energy level or use the VW arrows.
The Control output ranges are:
• Current: from 0.01 → 2.4 kA
• Voltage: 0.05 → 9.999 V
• Power: 0.01 → 9.999 kW
6. Perform one of the following:
•
From the CONTROL keys section on the front panel, press the kA key to program
current as the feedback mode.
7.
8.
•
•
From the CONTROL keys section on the front panel, press the V key to program
voltage as the feedback mode.
From the CONTROL keys section on the front panel, press the kW key to program
power as the feedback mode.
Press the PULSE 1 DOWNSLOPE key to enter the amount of time for the Weld Pulse 1
downslope. Use the numeric keypad or the VW arrows. Enter
Press the
COOL key to enter the amount of time for the cool period after Pulse 1. Use
0 milliseconds.
the numeric keypad to enter the time or use the VW arrows. Enter 0.5 milliseconds.
9. Program Pulse 2 by repeating Steps 3 through 7 above using the keys for Pulse 2, entering the
value 0 in each step.
10. Press the HOLD key to enter the amount of time for the hold period after the weld. Use
the numeric keypad or the VW arrows. Enter a time between
0 and 999 milliseconds.
We recommend at least 50 milliseconds as weld strength is formed in the hold time.
HF25D DC RESISTANCE WELDING SYSTEM
4-4 990-333
CHAPTER 4. OPERATING INSTRUCTIONS
Upslope/Downslope Weld Schedule
NOTE: If you are using the optional LVDT, you must perform the procedures described in Appendix
D, LVDT Option, Section 4, Operating Instructions in addition to the procedures below.
1. Press the SCHEDULE key, then select a Weld Schedule using either the VW arrows or
the numeric keypad.
2.
Press the SQUEEZE key to enter the squeeze time before the weld. Use the numeric
keypad to enter the time or use the VW arrows. We recommend 150ms.
3. Press the PULSE 1 UPSLOPE key to enter the amount of time for the Weld Pulse 1
upslope. Use the numeric keypad or the VW arrows to enter the time. Enter a time
between 0 and 99 milliseconds. A good starting point is 5 milliseconds.
4. Press the PULSE 1 WELD key to highlight the bottom line of the LCD to enter the weld
time. Use the numeric keypad to enter the time or use the VW arrows. Enter a time
between 0 and 99 milliseconds.
5. Press the PULSE 1 WELD key again to highlight the middle line of the LCD to enter
weld energy. Use the numeric keypad to enter the energy level or use the VW arrows.
The Control output ranges are:
• Current: from 0.01 → 2.4 kA
• Voltage: 0.05 → 9.999 V
• Power: 0.01 → 9.999 kW
6. Perform one of the following:
•
•
From the CONTROL keys section on the front panel, press the kA key to program
current as the feedback mode.
From the CONTROL keys section on the front panel, press the V key to program
voltage as the feedback mode.
7.
•
Press the PULSE 1 DOWNSLOPE key to enter the amount of time for the Weld Pulse 1
From the
power as the feedback mode.
downslope. Use the numeric keypad or the VW arrows to enter the time. Enter a time
between 0 and 99 milliseconds. A good starting point is 5 milliseconds.
8.
Press the COOL key to enter the amount of time for the cool period after Pulse 1. Use
the numeric keypad to enter the time or use the VW arrows. Enter 0.5 milliseconds.
9. Program Pulse 2 by repeating Steps 3 through 7 above using the keys for Pulse 2, entering the
value 0 in each step.
10.
Press the HOLD key to enter the amount of time for the hold period after the weld. Use
the numeric keypad or the VW arrows. Enter a time between 0 and 999 milliseconds.
We recommend at least 50 milliseconds as weld strength is formed in the hold time.
HF25D DC RESISTANCE WELDING SYSTEM
990-333 4-5
CONTROL keys section on the front panel, press the kW key to program
CHAPTER 4. OPERATING INSTRUCTIONS
Dual-Pulse Weld Schedule
NOTE: If you are using the optional LVDT, you must perform the procedures described in Appendix
D, LVDT Option, Section 4, Operating Instructions in addition to the procedures below.
1. Press the SCHEDULE key, then select a Weld Schedule using either the VW arrows or
the numeric keypad.
2. Press the SQUEEZE key to enter the squeeze time before the weld. Use the numeric
keypad to enter the time or use the VW arrows. We recommend 150ms.
3. Press the PULSE 1 UPSLOPE key to enter the amount of time for the Weld Pulse 1
upslope. Use the numeric keypad to enter the time or use the VW arrows. Enter a time
between 0 and 99 milliseconds.
4. Press the PULSE 1 WELD key to highlight the bottom line of the LCD to enter the weld
time. Use the numeric keypad to enter the time or use the VW arrows. Enter a time
between 0 and 99 milliseconds.
5. Press the PULSE 1 WELD key again to highlight the middle line of the LCD to enter
weld energy. Use the numeric keypad to enter the energy level or use the VW arrows.
The Control output ranges are:
• Current: from 0.01 → 2.4 kA
• Voltage: 0.05 → 9.999 V
• Power: 0.01 → 9.999 kW
6. Perform one of the following to program the Pulse 1 feedback mode:
•
•
•
From the CONTROL keys section on the front panel, press the kA key to program
current as the feedback mode.
From the CONTROL keys section on the front panel, press the V key to program
voltage as the feedback mode.
From the CONTROL keys section on the front panel, press the kW key to program
power as the feedback mode.
7. Press the PULSE 1 DOWNSLOPE key to enter the amount of time for the Weld Pulse 1
downslope. Use the numeric keypad to enter the time or use the VW arrows. Enter a
time between 0 and 99 milliseconds.
8.
Press the COOL key to enter the amount of time between Pulse 1 and Pulse 2. Use the
numeric keypad to enter the time or use the VW arrows. Enter a time between 0 and 99
milliseconds. We recommend at least 2 milliseconds.
9. Program Pulse 2 by repeating Steps 3 through 7 above using the keys for Pulse 2, entering
appropriate values for Pulse 2.
10. Press the HOLD key to enter the amount of time for the hold period after the weld. Use
the numeric keypad to enter the time or use the VW arrows. Enter a time between
999 milliseconds. We recommend at least 50 milliseconds.
and
0
HF25D DC RESISTANCE WELDING SYSTEM
4-6 990-333
CHAPTER 4. OPERATING INSTRUCTIONS
Section III. Programming the Weld Monitor
1. Press the SCHEDULE key, then select a Weld Schedule using either the VW arrows
or the numeric keypad. Fire the welder and view the output waveform (shaded graph)
on the display.
2. From the MONITOR keys section on the front panel, press the
, , ,
or key to view the desired waveform.
3.
Toggle the Pulse 1 weld time/energy selector key to select the upper limit field for the
weld period. Use the numeric keypad or the VW arrows to enter the upper limit value
for the Pulse 1 weld period.
4. Perform one of the following to program the Pulse 1 monitor limit mode:
•
Press the kA key to program current as the limit mode.
•
Press the V key to program voltage as the limit mode.
•
Press the kW key to program power as the limit mode.
5. Toggle the Pulse 1 weld time/energy selector key to select the lower limit field for the
weld period. Enter the lower limit value for the Pulse 1 weld period.
NOTE: In order for a Pulse 1 lower limit to be programmed, you must first program a
Pulse 1 upslope in the weld schedule.
The lower limit mode (current, voltage, or power) will automatically be the same as the
upper limit mode programmed in Step 5.
6.
Press the COOL weld period key.
This will bring up the PULSE 1
OUT OF LIMITS ACTION
screen.
This screen allows you to select
the action that the Control will
take if the Pulse 1 upper or lower
limits are exceeded. You have
PULSE 1 OUT OF LIMITS ACTION
1. none
2. STOP DURING PULSE 1
3. INHIBIT PULSE 2
4. APC: STOP PULSE 1/ALLOW PULSE 2
NUMBER Select, MENU Previous menu
four choices:
•
NONE takes no action if upper or lower energy limits are exceeded.
•
STOP DURING PULSE 1 stops the weld immediately during Pulse 1, and prevents
Pulse 2 from firing (if applicable).
• INHIBIT PULSE 2 stops the weld at the end of Pulse 1, and prevents Pulse 2 from
firing. This function will not operate if both pulses are joined without a cool time.
HF25D DC RESISTANCE WELDING SYSTEM
990-333 4-7
CHAPTER 4. OPERATING INSTRUCTIONS
prog
• APC: STOP PULSE 1/ALLOW PULSE 2 stops Pulse 1 immediately after upper or lower
energy limits are exceeded, but allows Pulse 2 to fire. This function will not operate
if both pulses are joined without a cool time.
NOTE: See Section IV, Programming For Active Part Conditioning.
7. After making your selection the display will automatically return to the monitor screen.
8. Program the upper and lower limits for Pulse 2 by repeating Steps 4 through 6 above using the
keys for Pulse 2, entering appropriate values for Pulse 2.
NOTES:
• The monitor limit mode (current, voltage, or power) for Pulse 2 can be different than
the monitor limit mode for Pulse 1.
• To “fine tune” the monitor limits to very precise values, see Section V, Adjusting
Monitor Limit Values.
9.
Press the HOLD period key.
This will bring up the PULSE 2
OUT OF LIMITS ACTION
screen.
This screen allows you to select
the action that the Control will
take if the Pulse 2 upper or
PULSE 2 OUT OF LIMITS ACTION
1. none
2. STOP DURING PULSE 2
NUMBER Select, MENU Previous menu
lower limits are exceeded. You
have two choices:
NONE takes no action if upper or lower energy limits are exceeded.
STOP DURING PULSE 2 stops PULSE 2 immediately after upper or lower energy
limits are exceeded.
10. After you have made your selection the
display will automatically return to the
MONITOR screen.
NOTE: The Control adds dotted lines
to the appropriate graph to show the
rammed limits.
The screen on the right shows how the
Limits and Alarm actions appear when
an actual weld trace is displayed on the
LCD.
NOTE: All lower limits apply only to the Pulse 1 and Pulse 2 WELD periods. Lower
limits do not cover any upslope or downslope periods. All upper limits apply to the entire
Pulse 1 and Pulse 2 periods, including their upslope and downslope periods.
HF25D DC RESISTANCE WELDING SYSTEM
4-8 990-333
CHAPTER 4. OPERATING INSTRUCTIONS
Section IV. Programming For Active Part Conditioning
Before you program for Active Part Conditioning, make sure you are familiar with these procedures
described in this manual:
• Chapter III, Using HF25 Welding And Monitoring Functions
• Chapter IV, Section III, Programming The Weld Monitor
1. Press the SCHEDULE key, then select a Weld Schedule using either the VW arrows
or the numeric keypad.
2. Program a single pulse for Constant Power operation. Program the power level and weld time
to cause slight sticking between the two parts. Make a few welds and pull them apart. Increase
or decrease the power setting until a light tack weld is achieved.
3.
4.
5.
6.
7.
From the MONITOR keys section on the front panel, press the voltage V key and
observe the high peak of the voltage waveform.
From the MONITOR keys section on the front panel, press the Ω (resistance) key and
observe the resistance waveform. This should appear to begin high, then start to drop as
a tack weld is made and oxides are removed.
From the MONITOR keys section on the front panel, press the kA (current) key and
observe the current waveform starting to rise as the oxidization breaks down. If the
current waveform starts to flatten, this is an indication that the resistance has stabilized
and the parts have come into closer contact.
Push RUN and optimize the energy and time setting of Pulse 1 (constant power) to
provide an adequate tack weld and also a current waveform (view in the monitor screen)
that has started to flatten out, but is still rising. This indicates that a full melt has not yet
occurred.
From the MONITOR keys section
on the front panel, press the kA
key to program an upper current
limit on the MONITOR screen.
NOTE: You can toggle between peak and average readings by pressing the
PEAK/AVERAGE key.
8.
9.
Press the
COOL weld period
key. This will bring up the
PULSE 1 OUT OF LIMITS
ACTION
Select
1/ALLOW PULSE 2.
screen.
4. APC: STOP PULSE
NOTE: For details, see "Active Part Conditioner" in Chapter 3.
HF25D DC RESISTANCE WELDING SYSTEM
990-333 4-9
PULSE 1 OUT OF LIMITS ACTION
1. none
2. STOP DURING PULSE 1
3. INHIBIT PULSE 2
4. APC: STOP PULSE 1/ALLOW PULSE 2
NUMBER Select, MENU Previous menu
CHAPTER 4. OPERATING INSTRUCTIONS
10.
11. Try welds with varying oxide (clean and dirty). The power supply terminates the first pulse
when your programmed current is reached. A clean part will reach the current limit sooner and
the pulse will terminate early. A dirty part will require more time before the oxide is broken
down and current can flow.
12. Program your second welding pulse as
normal to achieve a strong weld.
Constant voltage is recommended for
round parts and constant current for flat
parts. An upslope may be required to
restrict the current flow early in the
second pulse and avoid weld splash.
Since different levels of oxide require different amounts of time to reach the current
limit, return to the RUN screen and extend the programmed weld time (usually double
the time works). This will ensure that there will be enough time for the current to rise
and reach the limit, even with heavily oxidized parts.
HF25D DC RESISTANCE WELDING SYSTEM
4-10 990-333
CHAPTER 4. OPERATING INSTRUCTIONS
Section V. Adjusting Monitor Limit Values
The Control allows you to adjust extremely precise limits for the amount of energy and weld time. Like
all welding processs development, you’ll need to make several test welds, and view the waveforms and
limits of actual welds in order to “fine tune” the limits to your needs.
The energy limits appear as horizontal dotted lines on the LCD screen. The UPPER LIMIT line is longer
than the lower limit line because it includes the
actual weld waveform. The
the waveform. If the line of either limit crosses the weld energy waveform, the Control can trigger an
alarm, inhibit the second pulse, or stop the weld energy. See Section III for more details.
LOWER LIMIT line is shorter because it only includes the WELD portion of
UPSLOPE, WELD, and DOWNSLOPE portions of the
As you can see by the LCD screens above, you can shorten the length of the time of the
it will not cross the weld waveform. This allows you to raise or lower the LOWER LIMIT closer to the
peak of the actual waveform without crossing the weld waveform. For some welds it may be very
important to get up to the peak voltage or current to get the right melting and get there at the right time
during the pulse. Every millisecond could be very important.
HF25D DC RESISTANCE WELDING SYSTEM
990-333 4-11
LOWER LIMIT so
CHAPTER 4. OPERATING INSTRUCTIONS
1. Set an UPPER LIMIT and LOWER LIMIT using the procedures in Section III, Programming the
Weld Monitor.
2. Perform a weld to see how the limits (dotted lines) appear compared to the weld graph.
3. Raise or lower the
UPPER LIMIT and LOWER LIMIT as necessary using the procedures in Section
III, Programming the Weld Monitor.
4. To lengthen or shorten the time periods, go to the
MONITOR screen.
5. Press the UPSLOPE key for PULSE 1 or PULSE 2 to get the MONITOR LIMITS screen.
NOTE: INGNORE 1st deletes time
from the beginning of the limit, IGNORE
deletes time from the end of the
LAST
limit. This will not only shorten the
limit time, but depending on the amount
of time deleted on each end of the limit,
1. LOWER LIMIT IGNORE 1ST : 0.0ms
2. LOWER LIMIT IGNORE LAST : 2.5ms
3. UPPER LIMIT IGNORE 1ST : 0.0ms
4. UPPER LIMIT IGNORE LAST : 0.0ms
NUMBER Select, ENERGY Monitor screen
< PULSE 1 MONITOR LIMITS >
the limit will appear to move
horizontally across the screen. This
allows you to fit the LOWER LIMIT precisely into the waveform graph.
6. Use the numerical keypad to select the number of the limit you want to change.
7. When the value is highlighted (Example: 2.5ms), use the numerical keypad to type in a new
value.
8. Press the ENERGY key when you have finished entering new values.
9. Raise or lower the UPPER LIMIT and LOWER LIMIT as necessary using the procedures in
Section III, Programming the Weld Monitor.
10. Return to the RUN screen and make a test weld in order to view the waveform to see where
the new limits appear compared to the waveform graph.
11. Repeat steps 1 £ 10 until the limits are where you want them.
NOTE: Lower limits apply to the programmed weld time only. Programming a longer
upslope extends the time before a lower limit applies in the monitoring screen.
HF25D DC RESISTANCE WELDING SYSTEM
4-12 990-333
CHAPTER 5
MAINTENANCE
Section I. Introduction
General Kinds of Problems
It has been our experience that most resistance welding power supply ‘problems’ are caused by lack of
material control, process control and electrode tip surface maintenance. The problems that you might
encounter fall into two groups:
• Soft — The problem is transient, and you can correct it by resetting the system
or parameter limits. For example, you should ensure that:
− Correct force is set at the weld head
− Correct weld energy and time is set at the Control
− The equipment is set up properly
− All electrical connections are tight
− Electrode alignment allows flush contact with the weld pieces
− Electrodes are properly dressed
• Hard — The problem is embedded in the system and some form of repair will
be needed. For example, repair might include replacing a broken weld head
flexure.
Alarm Messages
Built-in automatic self-test and self-calibration routines will bring up alarm messages on the display
screens. These messages will usually let you know what action is required of you to correct the reason
for the alarm. For a complete listing of the alarm messages, what they mean, and corrective actions, see
Section II, Troubleshooting.
HF25D DC RESISTANCE WELDING SYSTEM
990-333 5-1
CHAPTER 5. MAINTENANCE
Section II. Troubleshooting
Troubleshooting
Problem Cause (in order of probability) Problem Cause (in order of probability)
Electrode
Damage
Electrode
Sticking
Insufficient
Weld
Nugget
1. Excessive current/energy set at HF25
1. Excessive or insufficient weld head
force
1. Wrong electrode tip shape
2. Excessive weld time set at HF25
2. Contaminated weld piece surface/
plating
2. Wrong electrode material
2. Contaminated electrode surface
1. Contaminated weld piece surface/
plating
1. Wrong electrode material/ tip shape
1. Insufficient weld head force
2. Excessive current/energy set at HF25
2. Excessive weld time set at HF25
2. Contaminated electrode surface
3. Slow weld head follow-up
1. Insufficient current/ energy set at HF25
1. Wrong electrode material/ tip shape
1. Worn/mushroomed electrodes
2. Insufficient weld time set at HF25
2. Incorrect weld head polarity
2. Contaminated weld piece surface/
plating
2. Excessive weld head force
3. Insufficient weld head force
3. Contaminated electrode surface
3. Incompatible weld piece projection
design
3. Slow weld head follow-up
4. Incompatible weld piece materials
4. No cover gas on weld piece
Electrode
Sparking
Weld Piece
Warping
Metal
Expulsion
1. Excessive current/energy set at HF25
1. Insufficient weld head force
1. Slow weld head follow-up
1. Incompatible weld piece projection
design
1. Contaminated weld piece surface/ plating
1. Wrong electrode tip shape
2. Wrong electrode material
2. Contaminated electrode surface
1. Excessive weld time set at HF25
1. Excessive weld head force
1. Incompatible weld piece projection
design
2. Incompatible weld piece materials
2. Wrong electrode tip shape
3. Excessive current/energy set at HF25
1. Excessive current/energy set at HF25
1. Insufficient weld head force
1. Slow weld head follow-up
1. Incompatible weld piece projection
design
2. Contaminated weld piece surface/ plating
2. Incompatible weld piece materials
2. Contaminated electrode surface
2. Wrong electrode tip shape
3. No cover gas on weld piece
4. Excessive weld time set at HF25
HF25D DC RESISTANCE WELDING SYSTEM
5-2 990-333
CHAPTER 5. MAINTENANCE
Problem Cause (in order of probability) Problem Cause (in order of probability)
Weld Piece
Overheating
1. Excessive weld time set at HF25
2. Excessive current/energy set at HF25
2. Insufficient weld head force
3. Incompatible weld piece materials
3. Wrong electrode material/tip shape
4. Contaminated electrode surface
Weld Piece
Discoloration
1. Excessive weld time set at HF25
1. No cover gas on weld piece
2. Excessive current/energy set at HF25
3. Insufficient weld head force
3. Contaminated weld piece surface/ plating
4. Wrong electrode material/tip shape
4. Contaminated electrode surface
Alarm Messages
Alarm Message Description Corrective Action
ACCESS DENIED!
SYSTEM
SECURITY ON
ACCESS DENIED!
SCHEDULE LOCK
ON
Operator tried to change a weld schedule
number, individual weld schedule
parameters, I/O switch functions, and
calibration parameters.
Operator tried to change a weld schedule
or individual weld parameters.
Press MENU, select System Security, then enter
the correct access code to turn off the System or
Calibration Lock protection features.
NOTE: Entering a security code of 280 will
always unlock the system.
Press MENU, select System Security, then enter
your access code to turn off System Security.
NOTE: Entering a security code of 280 will
always unlock the system.
CALIBRATION
RESET TO
DEFAULT
CHECK CONTROL
SIGNALS INPUT
STATUS
CHECK INPUT
SWITCH STATUS
CHECK VOLTAGE
CABLE
User entered calibration values reset to
factory default values.
One or more of the I/O input control
signals is preventing the HF25/26 from
continuing to operate.
One or more of the Firing or Foot Switch
input signals is preventing the HF25/26
from continuing to operate.
No electrode voltage measurement was
made.
Execute the built-in calibration procedure to get
the correct setting.
Remove the I/O input control signal condition
preventing further HF25/26 operation.
NOTE: The correct removal action depends on
how the control signal select in the Setup 1 menu
was programmed by the user.
Remove the I/O input control signal condition
preventing further HF25/26 operation.
NOTE: The correct removal action depends on
how the INPUT SWITCH SELECT in the Setup
1 menu was programmed by the user.
Verity that the Voltage Sense Cable is properly
connected to the electrodes or electrode holder.
NOTE: Polarity is not important for the cable
connection.
HF25D DC RESISTANCE WELDING SYSTEM
990-333 5-3
CHAPTER 5. MAINTENANCE
Alarm Message Description Corrective Action
CURRENT 1
GREATER THAN
UPPER LIMIT
CURRENT 2
GREATER THAN
UPPER LIMIT
CURRENT 1
LOWER THAN
LOWER LIMIT
CURRENT 2
LOWER THAN
LOWER LIMIT
EMERGENCY STOP
- OPERATOR
ACTIVATED
CHECK VOLTAGE
CABLE
Actual weld current is greater than the
user set Upper Limit value for Weld1.
Actual weld current is greater than the
user set Upper Limit value for Weld2.
Actual weld current is less than the user
set Lower Limit value for Weld1.
Actual weld current is less than the user
set Lower Limit value for Weld2.
The Operator Emergency Stop switch
has been activated. All power to the
HF25/26 is immediately terminated.
No electrode voltage measurement was
made.
Reset the Upper Limit for Weld1 to a larger
value.
Reset the Upper Limit for Weld2 to a larger
value.
Weld splash can cause the actual weld current to
drop below the user set Lower Limit for Weld1.
Add upslope to reduce weld splash.
Reset the lower Limit for Weld1 to a smaller
value.
Weld splash can cause the actual weld current to
drop below the user set Lower Limit for Weld2.
Add upslope to reduce weld splash.
Reset the lower Limit for Weld2 to a smaller
value.
Remove any unsafe operating conditions at the
welding electrodes.
Reset the Operator Emergency Stop switch.
Turn off power to the HF25/26, then turn it on
again
Verity that the Voltage Sense Cable is properly
connected to the electrodes or electrode holder.
NOTE: Polarity is not important for the cable
connection.
CURRENT 1
GREATER THAN
UPPER LIMIT
ENERGY SETTING
TOO SMALL
FIRING SWITCH
BEFORE FOOT
SWITCH
Actual weld current is greater than the
user set Upper Limit value for Weld1.
While in the voltage or power feedback
mode, the HF25/26 could not control the
energy setting because the required
current was smaller than the minimum
current specified.
The Firing Switch input has been
activated before the Foot Switch has
been activated, preventing weld current
from flowing.
Reset the Upper Limit for Weld1 to a larger
value.
Increase the energy setting.
Check the weld head for an improperly adjusted
firing switch.
Automation Only - Check the timing on the PLC
control lines to the Firing Switch and Foot
Switch inputs.
HF25D DC RESISTANCE WELDING SYSTEM
5-4 990-333
CHAPTER 5. MAINTENANCE
Alarm Message Description Corrective Action
FIRING DIDN’T
CLOSE IN 10
SECONDS
ILLEGAL
SECURITY CODE
ENTERED
INHIBIT CONTROL
SIGNALS
ACTIVATED
INPUT TOO LARGE The user has attempted to program a
INPUT TOO SMALL The user has attempted to program a
The Firing Switch on a Unitek air
actuated weld head did not activate
within 10 seconds after the Foot Switch
was initially activated.
The wrong security code was entered to
de-activate the System, Schedule, or
Calibration Lock protection features.
The Inhibit input control signal is
activated, preventing the HF25/26 from
continuing to operate.
NOTE: Activating the Inhibit input
terminates only future operations. It does
NOT terminate any present HF25/26
operation.
weld energy or time that exceeds the
capability of the HF25/26.
weld energy or time that is below the
capability of the HF25/26.
Press RUN and readjust the air pressure to the
Unitek air actuated weld head.
Press MENU, select System Security, then enter
the correct access code to turn off System,
Schedule, or Calibration Lock protection
features.
NOTE: Entering a security code of 280 will
always unlock the system.
Remove the Inhibit signal condition preventing
further HF25/26 operation.
NOTE: The correct removal action depends on
how the control signal I/O logic was
programmed by the user.
Re-program welding parameters to be within the
capability of the HF25/26.
Re-program welding parameters to be within the
capability of the HF25/26.
LOAD
RESISTANCE TOO
HIGH
LOW BATTERY The battery supplying backup power to
LOWER LIMIT
GREATER THAN
UPPER LIMIT
The total electrical resistance, comprised
of the weld cables, weld head, and parts
to be welded, has exceeded the drive
capability of the HF25/26.
The HF25/26 will not be able to
maintain the user set weld parameters.
the HF25/26 internal memory is out of
energy.
The user has tried to program a Lower
Limit value that is greater than the Upper
Limit value for Weld1 or Weld2 time
periods.
Reduce the total electrical resistance by reducing
the weld cable length.
Reduce the total electrical resistance by
increasing the weld cable diameter.
Check cable and weld head connections.
Verify that all three phases from the input power
lines are functioning
Replace the memory battery on the Main Control
PCB.
CAUTION: Replace the battery while power is
ON, otherwise all memory contents will be lost.
Re-program the invalid Lower Limit value.
HF25D DC RESISTANCE WELDING SYSTEM
990-333 5-5
CHAPTER 5. MAINTENANCE
Alarm Message Description Corrective Action
NO WELD
TRANSFORMER
DETECTED
POWER 1
GREATER THAN
UPPER LIMIT
POWER 2
GREATER THAN
UPPER LIMIT
POWER 1 LOWER
THAN LOWER
LIMIT
POWER 2 LOWER
THAN LOWER
LIMIT
Cable connecting the Control and Power
PCB’s is open.
Cable connecting the Power PCB to the
Weld Transformer is open.
Actual weld power is greater than the
user set Upper Limit value for Weld1.
Actual weld power is greater than the
user set Upper Limit value for Weld2.
Actual weld power is less than the user
set Lower Limit value for Weld1.
Actual weld power is less than the user
set Lower Limit value for Weld2.
Verify installation of the welding
transformer/rectifier module connections.
Weld splash can cause the actual weld power to
exceed the user set Upper Limit for Weld1. Add
upslope to reduce weld splash.
Reset the Upper Limit for Weld1 to a larger
value.
Weld splash can cause the actual weld power to
exceed the user set Upper Limit for Weld2. Add
upslope to reduce weld splash.
Reset the Upper Limit for Weld2 to a larger
value.
Weld splash can cause the actual weld power to
drop below the user set Lower Limit for Weld1.
Add upslope to reduce weld splash. Reset the
Lower Limit for Weld1 to a smaller value.
Weld splash can cause the actual weld power to
drop below the user set Lower Limit for Weld2.
Add upslope to reduce weld splash.
Reset the Lower Limit for Weld2 to a smaller
value.
POWER
TRANSISTOR
OVERHEATED
PROCESS STOP ON
CONTROL
SIGNALS INPUT
SAFE ENERGY
LIMIT REACHED
SCHEDULES ARE
RESET
The power dissipated by the power
transistors has exceeded the HF25/26
specified capability.
The Process Stop signal on the
CONTROL SIGNALS connector has
been activated, immediately terminating
weld current.
The HF25/26 internal power dissipation
has exceeded the HF25/26 specified
capability.
User programmed the HF25/26 to
automatically reset all 100 weld
schedules to their factory set default
values.
Reduce duty cycle.
Reduce weld time.
Remove the Process Stop activating signal from
the CONTROL SIGNALS connector.
Reduce duty cycle.
Reduce weld time.
CAUTION: Be careful when using the MENU
default features. There is no way to restore a
default action.
HF25D DC RESISTANCE WELDING SYSTEM
5-6 990-333
CHAPTER 5. MAINTENANCE
Alarm Message Description Corrective Action
SYSTEM
PARAMETERS ARE
RESET
SYSTEM &
SCHEDULE RESET
TO DEFAULTS
UPSLOPE
REQUIRED FOR
LOWER LIMIT
VOLTAGE 1
GREATER THAN
UPPER LIMIT
VOLTAGE 2
GREATER THAN
UPPER LIMIT
User programmed the HF25/26 to
automatically reset all I/O and other
system parameters to their factory set
default values.
User programmed the HF25/26 to
automatically reset all 100 weld
schedules, I/O and other system
parameters to their factory set default
values.
User has programmed a Lower Limit
value for Weld1 or Weld2 periods
without using an upslope period. The
HF25/26 will automatically stop when
activated because the starting weld
energy will always be lower than the
Lower Limit.
Actual weld voltage is greater than the
user set Upper Limit value for Weld1.
Actual weld voltage is greater than the
user set Upper Limit value for Weld2.
CAUTION: Be careful when using the MENU
default features. There is no way to restore a
default action.
CAUTION: Be careful when using the MENU
default features. There is no way to restore a
default action.
Delete the Weld1 or Weld2 Lower Limit value.
Add an upslope period before Weld1 or Weld2 if
a Lower Limit value is desired.
Weld splash can cause the actual weld voltage to
exceed the user set Upper Limit for Weld1. Add
upslope to reduce weld splash.
Reset the Upper Limit for Weld1 to a larger
value.
Weld splash can cause the actual weld voltage to
exceed the user set Upper Limit for Weld2. Add
upslope to reduce weld splash.
Reset the Upper Limit for Weld2 to a larger
value.
VOLTAGE 1
LOWER THAN
LOWER LIMIT
VOLTAGE 2
LOWER THAN
LOWER LIMIT
VOLTAGE
SELECTION PLUG
IS MISSING
Actual weld voltage current is less than
the user set Lower Limit value for
Weld1.
Actual weld voltage current is less than
the user set Lower Limit value for
Weld2.
The Voltage Selection Plug on the Weld
Transformer is missing or improperly
connected.
Reduce the weld cable length or increase the
diameter of the weld cables.
Reset the Lower Limit for Weld1 to a smaller
value.
Reduce the weld cable length or increase the
diameter of the weld cables.
Reset the Lower Limit for Weld2 to a smaller
value.
Verify the Voltage Selection Plug connection on
the Weld Transformer.
HF25D DC RESISTANCE WELDING SYSTEM
990-333 5-7
CHAPTER 5. MAINTENANCE
Alarm Message Description Corrective Action
WELD STOP LIMIT REACHED
WELD SWITCH IN
NO WELD
POSITION
WELD TIME TOO
SMALL
The user set Upper Limit value has been
exceeded and automatically terminated
the weld energy.
User has tried to activate the HF25/26
with the Weld/No Weld Switch in the
No Weld Position.
No weld current will flow.
The user has attempted to program zero
for all upslope, weld, and downslope
time periods.
This is a MONITOR LIMITS feature activated
by the selecting the ENERGY key, then
programming the Upper Limit values for Weld1
and Weld2.
If the terminated weld energy is not adequate for
the weld, re-set the Upper Limit values for
Weld1 and Weld2.
Set the Weld/No Weld switch to the Weld
position.
Re-program the welding parameters to be within
the capability of the HF25/26.
HF25D DC RESISTANCE WELDING SYSTEM
5-8 990-333
CHAPTER 5. MAINTENANCE
Section III. Maintenance
Electrode Maintenance
When a welding schedule has been suitable for a particular welding application over many welds, but
poor quality welds are now resulting, electrode deterioration could be the problem. If you need to
increase welding current to maintain the same weld heat, the electrode tip has probably increased in
surface area (mushroomed), effectively increasing weld current density, thus cooling the weld. Try
replacing the electrodes.
The rough surface of a worn electrode tip tends to stick to the work pieces. So, periodic tip resurfacing
(dressing) is required to remove pitting, oxides and welding debris from the electrode. You should limit
cleaning of an electrode on the production line to using a #400-600 grit electrode polishing disk. If you
must clean a badly damaged tip with a file, you must use a polishing disk after filing to ensure the
electrode faces are smooth.
The best method of preventing electrode problems is to regularly re-grind electrode tip surfaces and
shapes in a certified machine shop.
Parts Replacement
Below is a list of the replacement parts for the Control. All items listed are a quantity of 1 each.
WARNING: Only qualified technicians should perform internal adjustments or replace parts. Removal
of the unit cover could expose personnel to high voltage and may void the warranty.
Part Description Part No. Location
Input Power Line Protection Fuses F1 and F2:
HF25AX/240
HF25AX/400
HF25AX/480
Control Power Protection Fuse F1 330-078 Power PCB
Memory Backup Battery, Lithium 145-012 Control PCB
Input Power Selection Plug Set:
240 Volts
400 Volts
480 Volts
330-071
330-092
330-092
4-34314-01
4-34315-01
4-34316-01
Rear Panel
Welding Transformer
Chassis
HF25D DC RESISTANCE WELDING SYSTEM
990-333 5-9
CHAPTER 5. MAINTENANCE
Section III. Repair Service
If you have problems with your Control that you cannot resolve, please contact our service department
at the address, phone number, or e-mail address indicated in the Foreword of this manual.
HF25D DC RESISTANCE WELDING SYSTEM
5-10 990-333
CHAPTER 6
CALIBRATION
Calibration
The calibration procedure is initiated at the main menu, as described in Chapter 3, Using Programming
Functions, Section I, Menus. . The Control is calibrated by the software, using inputs from a calibration
setup during a weld process. Following a few calibration inputs, the Control will adjust itself and store
the calibration values in RAM, where they will be used as standards for the operational welding
parameters.
CAUTION: Only authorized personnel should perform this procedure.
Calibration Equipment Required
The required equipment for the setup is as follows:
• 2 weld cables, No. 2/0, 1 ft (30 cm) long, PN 2/0 BB11
• 1000µΩ coaxial shunt resistor accurate to ±0.2%.
Source for shunt resistor: Model R7500-8
T & M Research Products, Inc.
139 Rhode Island Street NE
Albuquerque, NM 87108
Telephone: (505) 268-0316
• Shielded voltage sense cable, PN 4-32998-01
• Digital oscilloscope, Tektronix 724C or equivalent
• Male BNC to dual binding post
• 2-wire, normally open switch for weld initiation, mating connector PN 520-011
• Coaxial BNC-to-BNC cable
NOTE: If you are using the optional LVDT, the only equipment required for LVDT
calibration is a piece of metal machined to an exact known thickness. This will be
placed between the electrodes as a reference. See Appendix D, LVDT Option, Section
III, Calibration.
HF25D DC RESISTANCE WELDING SYSTEM
990-333 6-1
Calibration Procedure
Initial Calibration Setup
1. Connect the calibration setup to the Control as shown.
CHAPTER 6: CALIBRATION
2. Turn the Control ON.
3. Press the MENU key to bring up the
main menu screen.
4. Press the 7 key to select the calibration
function. This will bring up the
calibration caution screen.
5. From the calibration caution screen,
press to continue. This will bring up
the pre-calibration screen.
6. From the pre-calibration screen, press
2 key to start the sequence of on-
the
screen calibration instructions.
<MAIN MENU>
1. SETUP 5.
COMMUNICATION
2. WELD COUNTER 6. RELAY
3. COPY A SCHEDULE 7. CALIBRATION
4. SYSTEM SECURITY 8. RESET TO
DEFAULTS
<CALIBRATION CAUTION>
CALIBRATION SHOULD BE PERFORMED BY A
QUALIFIED TECHNICIAN ONLY.
REFER TO MANUAL FOR CALIBRATION SETUP.
▼Next, Menu menu
1. TEST HF25
2. CALIBRATE HF25
3. RESET CALIBRATION
4. SET CURRENT SHUNT VALUE
5. TEST SERIAL PORT
▼Next, Menu menu
<PRE-CALIBRATION>
HF25D DC RESISTANCE WELDING SYSTEM
990-333 6-2
CHAPTER 6: CALIBRATION
7. The first calibration screen is the CALIBRATION SHUNT. This screen asks for the actual
value of the 1000 micro-ohm shunt. The actual value is printed on the exterior of the
R7500-8 shunt. Enter this value using the number keys, and press to continue.
NOTE: The next calibration screen is the
CURRENT SHUNT. It is not necessary to change the
current shunt value unless the internal welding transformer was changed. If it was changed,
remove the top cover and enter the shunt value, which is stamped on the copper conductor
connected to the transformer. Press
to continue.
8. The next two screens are
D/A HIGH
and 2. CALIBRATE D/A LOW.
1. CALIBRATE
Following the screen instructions, adjust
the energy output using the measuring
parameter feature of the oscilloscope.
NOTE: Do not use a visual
assessment. Press the period [ . ] key to
advance to the next step.
Calibration Signal
9. The next calibration screen is CALIBRATE HIGH. Disconnect the oscilloscope from the shunt
resistor and connect the output of the shunt resistor to the VOLTAGE SENSE INPUT
connector using the male BNC to binding post adapter and voltage sense cable. Follow the
screen instructions for this step and the next step, 4. CALIBRATION LOW.
HF25D DC RESISTANCE WELDING SYSTEM
990-333 6-3
CHAPTER 6: CALIBRATION
Final Calibration Setup
HF25D DC RESISTANCE WELDING SYSTEM
990-333 6-4
10. The last calibration screen is 5. END OF CALIBRATION. Press the MENU key. The
calibration is now complete.
CHAPTER 6: CALIBRATION
Calibrating the LVDT
If you are using the LVDT option, follow the calibration procedures described in Appendix D, LVDT
Option, Section 3, LVDT Calibration.
HF25D DC RESISTANCE WELDING SYSTEM
990-333 6-5
APPENDIX A
TECHNICAL SPECIFICATIONS
NOTE: The specifications listed in this appendix may be changed without notice.
Power
Input Power Line .................................................................................................... 50-60 Hz, 3 phase
Input Voltage Range at Maximum Output Current
HF25A10/240 ................................................................................................192-264 VAC at 25A
HF25DA10/240 .............................................................................................. 192-264 VAC at 25A
HF25A10/400 ................................................................................................320-440 VAC at 20A
HF25DA10/400 .............................................................................................. 320-440 VAC at 20A
HF25A10/480 ................................................................................................384-528 VAC at 13A
HF25A10/480 ................................................................................................384-528 VAC at 13A
HF25DA10/480 .............................................................................................. 384-528 VAC at 13A
Input kVA (Demand) ........................................................................... 30 kVA max at 3% duty cycle
Output Power at 12% Duty Cycle and a
Combined PULSE 1 and PULSE 2 Pulse Width of 50 ms ................................6.0 kW max
Maximum Output Current ........................................................................................................2400A
Max Peak Output Voltage at Max Peak Output Current..........................................................5.2V
Duty Cycle at Max Peak Output Current ..................................................................................... 3%
Max Load Resistance for Max Output Current ..................................................................... 2.1mΩ
Output Adjustment Range, Resolution and Accuracy
NOTE: Actual maximum and minimum current, voltage or power achievable depends on
transformer and load resistance.
Parameter Adjustment Range Resolution (Steps) Accuracy
Current 50 - 2400 A 0.001 kA ± (2% of setting +2A)
Voltage 0.2 - 5 V 0.001 V ± (2% of setting +0.02V)
Power 0.01-9.999 kW 0.001 kW ± (5% of setting +10W)
Weld Periods 0.0 - 9.9 ms
10 - 99 ms
0.1 ms
1.0 ms
± 20 µs
HF25D DC RESISTANCE WELDING SYSTEM
990-333 A-1
APPENDIX A: TECHNICAL SPECIFICATIONS
Performance Capabilities
Number of Weld Schedules...................................................................................................................100
Programmable Weld Periods:
Squeeze .................................................................................................................................0 - 999 ms
Upslope 1 .................................................................................................................................0 - 99 ms
Weld 1 ...................................................................................................................................0 - 99 ms
Downslope 1 ............................................................................................................................0 - 99 ms
Cool ...................................................................................................................................0 - 99 ms
Upslope 2 ................................................................................................................................0 - 99 ms
Weld 2 ...................................................................................................................................0 - 99 ms
Downslope 2 ............................................................................................................................0 - 99 ms
Hold .................................................................................................................................0 - 999 ms
Weld Head System Compatibility
Force Fired, Foot Actuated
Force Fired, Single Valve Air Actuated
Non Force-Fired, Single Valve Air or Cam Actuated
Force Fired, EZ Air Kit
Weld Energy Limits Monitoring
Energy Limit Mode: Terminate weld energy upon reaching the programmed current, voltage,
power or resistance alarm level.
Weld Pre-Check Mode: Inhibit second weld pulse when first test pulse exceeds programmed limits.
Measurement Parameters: Current, voltage and power.
Measurement Selection: Peak or average.
Measurement Range and Accuracy:
Parameter Range Accuracy
Current 0.01 - 2.4 kA ± (2% of setting +2A)
Voltage 0.05 - 9.999 V ± (2% of setting +0.02V)
Power 0.01 - 9.999 kW ± (5% of setting +10W)
Limit Ranges: Same as the measurement ranges
Alarms: Display alert and four programmable AC/DC relay contact outputs.
HF25D DC RESISTANCE WELDING SYSTEM
A-2 990-333
APPENDIX A: TECHNICAL SPECIFICATIONS
Input Signals
NOTE: Except where parenthetically noted below, all input signals accept 5 to 24 VDC, normally open
or normally closed, positive or negative logic. Inputs are optically isolated.
Firing Switch Initiation: 1-level foot switch, 2-level foot switch or opto firing switch.
Remote Control Barrier Strip: Remote weld schedule select, process inhibit, emergency stop and
force control (0 - 5 VDC).
RS232: Change weld schedules and individual weld parameters.
RS485: Change weld schedules and individual weld parameters. “Daisy chain” RS485 input with
RS485 output from other HF25 controls and host computer.
Voltage: Weld voltage signal for voltage feedback operation (0 to 10 volt peak).
Output Signals
Monitor: Internal analog voltage signals representing secondary current feedback (0-5 VDC),
primary current (0-4 VDC), or weld voltage (0-5VDC).
Air Valve Driver: 24 VAC, 1 amp; timing controlled by the HF25. No weld over-force protection.
“EZ” Air Valve Driver: 24 VDC, 1.5 amps: timing controlled by the HF25. Weld over-force
protection.
Alarm Relay: Four programmable mechanical relays: 250 VAC or 30 VDC at 5 amps.
RS232: Monitor weld parameter data. Download and upload schedules.
RS485: Monitor weld parameter data. “Daisy chain” RS485 input with RS485 output from other
HF25 Controls and host computer. Download and upload schedules.
Physical
Size:
Height .................................................................................................................12.8 in. (325 mm)
Width .......................................................................................................................9 in. (230 mm)
Depth .......................................................................................................................18.0 (460 mm)
Weight .......................................................................................................................... 62 lbs. (28 kg)
HF25D DC RESISTANCE WELDING SYSTEM
990-333 A-3
APPENDIX A: TECHNICAL SPECIFICATIONS
Shipping Kit Contents
Part Description Part No. Qty
Voltage Sense Cable Assembly 4-32998-01 1
Power Supplies Operator’s Guide 991-342 1
Machine Bolt, Hex Head, 5/16-18 x 1 160-016 2
Jam Nut, 5/16-18, for weld cable 465-049 2
Flat Washer, 5/16, for weld cable 755-044 4
Spring Lock Washer 755-228 2
Voltage Pick Up Clip Assembly, 1/4 in. 4-32999-01 2
Voltage Pick Up Clip Assembly, 1/8 in. 4-32999-02 2
Connector, 15-Pin D-Type 250-199 1
Accessory, 15-pin 250-200 1
Optional Accessories
Accessory Part Number
2-Level Foot Switch FS2L
DC25/UB25/HF25 Datacom Kit 10-600-06
DATACOM Kit Contents
Part Description Part No. Qty
9-Pin to 9-Pin Data Communication Cable, 6 ft (183 cm) 205-135 1
Weldstat User’s Manual 990-661 1
DATACOM Software CD, 3.5 inch 4-36039-01 1
HF25D DC RESISTANCE WELDING SYSTEM
A-4 990-333
APPENDIX B
ELECTRICAL AND DATA CONNECTIONS
Electrical Connection
As described in Chapter 2, you need to supply a connector for the Control input power cable (refer to
diagram below for wiring information).
Connect the Control power cable to a 3-phase, 50/60Hz power source. The voltage range for each
model is set at the factory by a set of two jumper plugs. One jumper plug is installed on power
connector J23, located on the center chassis plate. The other jumper plug, P22, plugs into welding
transformer cable connector J22. The jumper plug set determines the power wiring configuration
between the power board and the welding transformer.
Input Power Wiring Diagram
CAUTIONS:
• Be sure that the shop source power is appropriate for your Control model.
• If the blue phase wire is not connected, no alarm will occur and the weld control will produce
more than 20% ripple in the weld output waveform.
Welding Transformer Specifications
Model
HF25A10
(all voltages)
Max Peak Output
Current (A)
2,400 5.2 3% 2.1
HF25D DC RESISTANCE WELDING SYSTEM
990-333 B-1
Max Peak Output
Voltage (V) at Max
Peak Output
Current
Duty Cycle at Max
Peak Output
Current
Max Load
Resistance
(mΩ) for Max
Output Current
APPENDIX B: ELECTRICAL AND DATA CONNECTIONS
I/O Signal Interface General Description
I/O Signal Interface Physical Organization
All signals transferred between the Control and external devices enter and leave the unit through the I/O
signal interface. The interface consists of terminal block plugs connected to bulkhead connectors,
CONTROL SIGNALS and MONITOR connectors, and additional connectors (as shown) attached to a
detachable connector box.
The interface can be used in either of two ways. In the standard form, the Control is shipped with the
connector box in place. Signals are transferred through the interface via the connectors on the connector
box, which are pre-wired to the terminal block plugs. Thus, you have an easy way to attach a weld
head, foot switch, firing switch, and air valve driver to the Control without having to solder or splice
wires.
In the optional form, you can open the connector box and run external device wiring directly into the
interface through the terminal block plugs.
HF25D DC RESISTANCE WELDING SYSTEM
B-2 990-333
APPENDIX B: ELECTRICAL AND DATA CONNECTIONS
The bulkhead connectors that receive the six removable terminal block plugs are connectors J1, J2 and
J3 on the control board. The terminal block plug to control board connector pin relationship is as
follows:
J1
Pins 1-10
J1
Pins 11-20
J2
Pins 1-10
J2
Pins 11-20
J3
Pins 1-10
J3
Pins 11-20
TB1
Pins 1-10
TB2
Pins 11-20
TB3
Pins 21-30
TB4
Pins 31-40
TB5
Pins 41-50
TB6
Pins 51-60
Operator Emergency Stop Switch Input
Function
The Control is delivered with the operator emergency stop cable leads connected to power interlock
contacts J3-1 and J3-2 on the control board, via TB5. You must connect a normally closed, single-pole
switch across the cable leads, otherwise the Control cannot be turned on. Use the switch during Control
operation as an emergency stop switch. When operated (opened), it will immediately halt the weld
process.
NOTE: You must press the
stop operation.
Emergency Stop Switch Input Schematic
RUN key on the front panel to reset the Control following an emergency
HF25D DC RESISTANCE WELDING SYSTEM
990-333 B-3
APPENDIX B: ELECTRICAL AND DATA CONNECTIONS
Connections
Connect an approved, normally closed emergency stop switch across the 2-foot (61 cm) operator
emergency stop switch cable. The cable is routed through the side of the connector box on the rear
panel. When the switch is operated (opened), it de-energizes the main power contactor, removing threephase input power to the Control.
Operator Emergency Stop Switch Cable Pin Assignment Summary
TB5
Pin No.
41 CONTRET AC 1 24 VAC
42 24VAC AC 2 24VAC 10mA I Emergency stop switch
Signal
Name Type
Control
Board
J3
Max
Voltage
GND
Max
Current
10mA O Contactor Return
I/O Comments
normally closed contact
Force Firing Switch Input
Function
The force-firing switch input to the Control from the weld head signals that the selected pressure has
been applied to the weld pieces. Note that a mechanical firing switch is subject to contact bounce,
which can cause false weld starts. The effects of switch bounce can be avoided at low weld speeds by
using the switch debounce function on the Control main menu. If welding speeds are to exceed 1.5
welds per second, use an optical firing switch.
Connections
The firing switch cable is a Type 2/C, 600-volt cable containing two shielded, twisted pair 22 AWG
stranded leads. It is 5 feet long.
The firing switch cable connector is a 2-pin Amphenol Type 80-MC2FI. It mates with the weld head
firing switch connector, which is a 2-Pin Amphenol Type 80-MC2M.
If the weld head uses an opto coupler instead of a mechanical switch, its emitter is connected to digital
ground (Pin 1).
If the firing switch is from a PLC (with a positive-voltage input), the factory-installed jumper between
pins 19 and 20, are moved between 19 and 18 (ground).
HF25D DC RESISTANCE WELDING SYSTEM
B-4 990-333
APPENDIX B: ELECTRICAL AND DATA CONNECTIONS
Force Firing Switch Input Schematic Diagram – Standard Configuration
Force Firing Switch Input Schematic Diagram -- Alternate Configuration (for PLC)
HF25D DC RESISTANCE WELDING SYSTEM
990-333 B-5
APPENDIX B: ELECTRICAL AND DATA CONNECTIONS
FIRING SWITCH Connector Pin Assignment Summary
Pin No.
1 FIREG Digital 2-12 J1-12 SGND 20mA Firing switch ground
2 FIRE1 Digital 2-11 J1-11 +24V 10mA I Firing switch normally
Shld CGND -- 2-15 J1-15 CGND -- -- Chassis ground
Signal Destinations
Name Type TB
Control
Board
Max
Voltage
Max
Current
I/O Comments
open contact
Two-Level Foot Switch Input
Function
When you press the foot switch to the first level, the Control energizes the air actuated weld head. This
causes the upper electrode to descend and apply force to the weld pieces. If you release the foot switch
before pressing it to the second level, the Control will automatically return the upper electrode to its UP
position so that you may re-position the weld pieces.
If you do not release the foot switch at the first level and proceed to the second level, the force-firing
switch in the weld head will close. Weld current will flow, and the Control will automatically return the
upper electrode to its UP position.
Connections
Connect the Unitek Peco Model FS2L Foot Switch, double-pole single-throw reed relay, or the open
collectors of opto couplers to the FOOT SWITCH connector on the Control connector box. If using opto
couplers, connect the emitters to Pin 4 (GND) of the FOOT SWITCH connector.
If the foot switch signal is from a PLC (with a positive-voltage input), the factory-installed jumper
between pins 19 and 20, are moved between 19 and 18 (ground).
HF25D DC RESISTANCE WELDING SYSTEM
B-6 990-333
APPENDIX B: ELECTRICAL AND DATA CONNECTIONS
Two-Level Foot Switch Input Schematic Diagram –Standard Configuration
Two-Level Foot Switch Input Schematic Diagram -- Alternate Configuration (for PLC)
HF25D DC RESISTANCE WELDING SYSTEM
990-333 B-7
APPENDIX B: ELECTRICAL AND DATA CONNECTIONS
FOOT SWITCH Connector Pin Assignment Summary
Pin
No.
1 CGND -- 2-15 J1-15 CGND -- -- Chassis ground
2 FOOT1 Digital 2-16 J1-16 +24V 10mA I Foot switch SW1 (Level 1)
3 FOOT2 Digital 2-17 J1-17 +24V 10mA I Foot switch SW2 (Level 2)
4 FOOTG Digital 2-18 J1-18 SGND 20mA I Foot switch signal ground
Signal Destinations
Name Type TB
Cntrol
Board
Voltage Max
Current
I/O Comments
normally open contact
normally closed contact
Remote Schedule Selection Inputs
Function
The are two ways to use the remote schedule selection inputs:
• Schedule Selection Function
• Schedule Initiation Function
Schedule Selection Function
All weld schedules must be entered and saved to the Control memory locally, through the Control
control panel. Once they are saved, they can be recalled prior to initiating the weld process by placing a
BCD value on the remote schedule selection lines. This may be done with either an external
programmed logic controller (PLC) or host computer.
The INHIBIT output signal from the Control can be used to prevent the PLC from beginning a new
welding process. The STOP output signal from the Control can be used to terminate the active weld
process under an emergency condition. Typical PLC timing in relationship to weld head timing is
shown in the PLC Timing Diagram on the next page.
HF25D DC RESISTANCE WELDING SYSTEM
B-8 990-333
APPENDIX B: ELECTRICAL AND DATA CONNECTIONS
PLC Timing Diagram
BCD Welding Schedule Selection Scheme
Weld
Schedule
No.
Bit 2
Pin 1
0
Bit 21
Pin 2
Bit 22
Pin 3
Bit 23
Pin 4
Bit 24
Pin 12
Bit 25
Pin 5
Bit 26
Pin 14
0 0 0 0 0 0 0 0
1 1 0 0 0 0 0 0
2 0 1 0 0 0 0 0
3 1 1 0 0 0 0 0
4 0 0 1 0 0 0 0
5-98 BCD progression from 5 to 98
99 1 1 0 0 0 1 1
HF25D DC RESISTANCE WELDING SYSTEM
990-333 B-9
APPENDIX B: ELECTRICAL AND DATA CONNECTIONS
Schedule Initiation Function
In addition to selecting weld schedules, the remote schedule selection inputs can be used to
automatically initiate the welding cycle, eliminating the need for a firing switch or foot switch input. By
selecting the
FIRING SWITCH: REMOTE option from the main menu, weld energy will flow 20
milliseconds after the squeeze period expires.
Connections
Mechanical switches, opto couplers and programmable logic controls (PLC) can be used to select and
initiate weld schedules. The
CONTROL SIGNAL SELECT: option on the main menu lists the types of
input switch devices used by the Control.
The CONTROL SIGNAL SELECT: option allows you to select the switch actuation state (open or closed).
For example, a mechanical switch can be closed, thus initiating the welding process. Or, it can be
programmed to begin initiation when opened.
Similarly, a PLC can input +5 to +24 VDC to trigger the welding process. Conversely, you can program
the Control to start the welding process when the input signal from the PLC drops from +5 or 24 VDC
to 0 volts.
CONTROL SIGNALS
Connector Pin Assignments (Remote Schedule Select Signals Only)
Signal Destinations
Pin No.
1 SCH20 Digital 3-24 J2-4 +24VDC 10mA I Rem Schedule Sel 20
Name Type TB Control
Board
Max
Voltage
Max
Current
I/O Comments
2 SCH21 Digital 3-25 J2-5 +24VDC 10mA I Rem Schedule Sel 21
3 SCH22 Digital 3-26 J2-6 +24VDC 10mA I Rem Schedule Sel 22
4 SCH23 Digital 3-27 J2-7 +24VDC 10mA I Rem Schedule Sel 23
12 SCH24 Digital 3-28 J2-8 +24VDC 10mA I Rem Schedule Sel 24
5 SCH25 Digital 3-29 J2-9 +24VDC 10mA I Rem Schedule Sel 25
14 SCH26 Digital 3-30 J2-10 +24VDC 10mA I Rem Schedule Sel 26
9 INHIBIT Digital 4-31 J2-11 +24VDC 10mA I Process inhibit (Reset)
10 STOP Digital 4-32 J2-12 +24VDC 10mA I Weld stop
11 24GND n/a 3-23 J2-3 n/a n/a n/a 24 volt ground
HF25D DC RESISTANCE WELDING SYSTEM
B-10 990-333
APPENDIX B: ELECTRICAL AND DATA CONNECTIONS
Mechanical Switch or Opto Coupler Input Schematic Diagram
HF25D DC RESISTANCE WELDING SYSTEM
990-333 B-11
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