Amada HF28/240 User manual

990-372 REV E
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DC RESISTANCE WELDING SYSTEM
HF28
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OPERATION MANUAL
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HF28 DC RESISTANCE WELDING SYSTEM
ii 990-372
Copyright © 1998 -- 2015 Amada Miyachi America
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Theengineeringdesigns,drawingsanddatacontainedhereinaretheproprietaryworkof
AmadaMiyachiAmericaandmaynotbereproduced,copied,exhibitedorotherwise
usedwithoutthewrittenauthorizationofAmadaMiyachiAmerica.
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PrintedintheUnitedStatesofAmerica.
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Revision Record
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Revision EO Date Basis of Revision
A 20409 06/05 None. Original edition.
B 34461 12/09 Updated technical information & specifications.
C 42840 10/13 Updated to Miyachi America name and logo.
D 43480 11/14 Updated to Amada Miyachi America name and logo.
E 43808 8/15 Updated to Amada Miyachi format.
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Important Note
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This manual describes HF28 Models 1-310-01, 1-310-01-01, 1-310-01-02
manufactured after June 2005. These contain significant differences than
earlier models. HF28 models 1-288-01 and 1-288-01-01 manufactured
before June 2005 require a different manual.
To get User’s Manual 990-335 for older HF28 models, order a copy
using the phone number or e-mail address listed under Contact Us on
page viii of this section.
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HF28 DC RESISTANCE WELDING SYSTEM
990-372 iii
CONTENTS Page
Revision Record ........................................................................................................................................ ii
Contents ....................................................................................................................................... iii
Contact Us ..................................................................................................................................... viii
Safety Notes ....................................................................................................................................... ix
Declaration Of Conformity .........................................................................................................................x
Warranty ....................................................................................................................................... xi
Chapter 1. Description
Section I. Features .................................................................................................................................. 1-1
Section II. Major Components ............................................................................................................... 1-3
Major Components .......................................................................................................................... 1-3
Front Panel Display and Display Controls ...................................................................................... 1-3
Display ..................................................................................................................................... 1-4
Display Controls ....................................................................................................................... 1-5
SCHEDULE Key .............................................................................................................. 1-5
Weld Period Selector Keys ............................................................................................... 1-5
Time/Energy Selector Keys .............................................................................................. 1-5
Front Panel Data Entry and Mode Keys .......................................................................................... 1-6
Key Pad .................................................................................................................................... 1-6
Mode Keys ................................................................................................................................ 1-6
RUN Key ........................................................................................................................... 1-6
MENU Key ....................................................................................................................... 1-6
Control Keys .................................................................................................................................... 1-6
Control Mode Selection Keys .................................................................................................. 1-7
kA Key .............................................................................................................................. 1-7
V Key ................................................................................................................................ 1-7
kW Key ............................................................................................................................. 1-7
Monitor Keys ............................................................................................................................ 1-7
kA Key .............................................................................................................................. 1-7
V Key ................................................................................................................................ 1-7
kW Key ............................................................................................................................. 1-8
ΩKey ................................................................................................................................ 1-8
WELD/NO WELD Switch ....................................................................................................... 1-8
Emergency Stop Switch Operation .................................................................................................. 1-8
Chapter 2. Installation and Setup
Section I: Installation ............................................................................................................................. 2-1
Unpacking ..................................................................................................................................... 2-1
Space Requirements ......................................................................................................................... 2-1
Utilities ..................................................................................................................................... 2-2

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CONTENTS (Continued) Page
Power ..................................................................................................................................... 2-2
Compressed Air and Cooling Water ................................................................................................ 2-2
Section II: Setup ..................................................................................................................................... 2-3
Connections to External Equipment ................................................................................................ 2-3
Rear Panel Components and Connectors ......................................................................................... 2-3
Weld Head Connections .................................................................................................................. 2-4
Foot Pedal-Actuated Weld Head Connection .................................................................................. 2-6
EZ-AIR Weld Head Connections .................................................................................................... 2-7
Non-EZ-AIR Weld Head Connections .......................................................................................... 2-10
Chapter 3. System Configuration
Section I: Menus .................................................................................................................................... 3-1
Before You Start .............................................................................................................................. 3-1
Overview ..................................................................................................................................... 3-1
Main Menu ..................................................................................................................................... 3-1
1. Setup .................................................................................................................................... 3-1
2. Weld Counter ....................................................................................................................... 3-2
3. Copy A Schedule ................................................................................................................. 3-3
4. Calibration ........................................................................................................................... 3-3
5. System Security ................................................................................................................... 3-3
1. Schedule Lock .............................................................................................................. 3-4
2. System Lock ................................................................................................................. 3-4
3. Calibration ................................................................................................................... 3-4
6. Relay .................................................................................................................................... 3-5
7. Reset To Defaults ................................................................................................................ 3-6
1. Reset System Parameters ............................................................................................. 3-6
2. Reset All Schedules ...................................................................................................... 3-7
3. Reset Schedule Limits .................................................................................................. 3-7
8. Chain Schedules .................................................................................................................. 3-7
Setup 1 ..................................................................................................................................... 3-9
1. Footswitch Weld Abort ................................................................................................ 3-9
2. Switch Debounce Time .............................................................................................. 3-10
3. Firing Switch .............................................................................................................. 3-10
Setup 2 ................................................................................................................................... 3-11
1. Display Contrast ................................................................................................................ 3-11
2. Buzzer Loudness ............................................................................................................... 3-11
3. End Of Cycle Buzzer ......................................................................................................... 3-11
4. Update Graph After Weld ................................................................................................. 3-11
5. Language ........................................................................................................................... 3-12

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Page
Setup 3 ................................................................................................................................... 3-12
Do Test Weld .......................................................................................................................... 3-12
Always ............................................................................................................................. 3-12
Ask .................................................................................................................................. 3-12
Section III. Operational States ............................................................................................................. 3-13
No Weld State ................................................................................................................................ 3-13
Menu State ................................................................................................................................... 3-13
Test State ................................................................................................................................... 3-13
Run State ................................................................................................................................... 3-14
Weld State ................................................................................................................................... 3-15
Monitor State ................................................................................................................................. 3-15
Alarm State ................................................................................................................................... 3-16
Section IV. Weld Functions ................................................................................................................. 3-17
Welding Applications .................................................................................................................... 3-17
Weld Head Applicability ............................................................................................................... 3-18
When To Use Functions ................................................................................................................ 3-18
Weld Schedule Definition .............................................................................................................. 3-19
Weld Sequence Timing .................................................................................................................. 3-19
Welding Applications .................................................................................................................... 3-20
Single-Pulse Weld Profile ...................................................................................................... 3-20
Upslope / Downslope Weld Profile ........................................................................................ 3-21
Dual-Pulse Weld Profile ......................................................................................................... 3-21
Chapter 4. Introduction to Feedback Modes and Monitoring
Section I. Programmable Feedback Modes ........................................................................................... 4-1
Introduction ..................................................................................................................................... 4-1
Current Mode ................................................................................................................................... 4-1
Voltage Mode .................................................................................................................................. 4-1
Power Mode ..................................................................................................................................... 4-2
Section II. Weld Monitoring .................................................................................................................. 4-3
Introduction ..................................................................................................................................... 4-3
PEAK and AVERAGE MONITORING ......................................................................................... 4-3
Current, Voltage, Power, and Resistance Limits ............................................................................. 4-4
Process Tools ................................................................................................................................... 4-4
1. Active Part Conditioner (APC) ........................................................................................... 4-4
2. Resistance Set ...................................................................................................................... 4-6
3. Pre-Weld Check ................................................................................................................... 4-7
4. Weld To A Limit ................................................................................................................. 4-8
5. Weld Stop ............................................................................................................................ 4-9

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CONTENTS (Continued) Page
Chapter 5. Operating Instructions
Section I: Introduction ........................................................................................................................... 5-1
Before You Start .............................................................................................................................. 5-1
Pre-Operational Checks ................................................................................................................... 5-1
Connections .............................................................................................................................. 5-1
Power ..................................................................................................................................... 5-1
Compressed Air ........................................................................................................................ 5-1
Initial Setup ..................................................................................................................................... 5-2
Section II. Operation .............................................................................................................................. 5-3
Single-Pulse Weld Schedule ............................................................................................................ 5-3
Upslope/Downslope Weld Schedule ............................................................................................... 5-5
Dual-Pulse Weld Schedule .............................................................................................................. 5-7
Section III. Using the Weld Monitor ..................................................................................................... 5-9
Section IV. Active Part Conditioning .................................................................................................. 5-13
Section IV. Resistance Set ................................................................................................................... 5-15
Section VI. Pre-Weld Check ................................................................................................................ 5-17
Section VII. Weld To A Limit ............................................................................................................. 5-19
Section VIII. Weld Stop ....................................................................................................................... 5-21
Section IX. Programming Relays ......................................................................................................... 5-23
Chapter 6. Maintenance
Section I. Introduction ......................................................................................................................... 6-1
General Kinds of Problems .............................................................................................................. 6-1
Alarm Messages ............................................................................................................................... 6-1
Section II. Troubleshooting ................................................................................................................... 6-2
Troubleshooting ............................................................................................................................... 6-2
Alarm Messages ............................................................................................................................... 6-3
Section III. Maintenance ........................................................................................................................ 6-9
Electrode Maintenance .................................................................................................................... 6-9
Parts Replacement ........................................................................................................................... 6-9
Section IV. Repair Service ................................................................................................................... 6-10

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990-372 vii
CONTENTS (Continued) Page
Appendix A. Technical Specifications ............................................................................................... A-1
Appendix B. Electrical and Data Connections ..................................................................................B-1
Appendix C. Calibration .....................................................................................................................C-1
Appendix D. System Timing .............................................................................................................. D-1
Appendix E. The Basics of Resistance Welding ................................................................................E-1
Appendix F. Quality Resistance Welding Solutions: Defining the Optimum Process .................F-1
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HF28 DC RESISTANCE WELDING SYSTEM
viii 990-372
CONTACT US
Thank you for purchasing a Miyachi Unitek™ 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 us at:
Amada Miyachi America
1820 South Myrtle Avenue
P.O. Box 5033
Monrovia, CA 91017-7133
Telephone: [phone]
FAX: [phone]
e-mail: [email protected]
The purpose of this manual is to supply operating and maintenance personnel with the information
needed to properly and safely operate and maintain the Miyachi Unitek™ HF28 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.
Amada Miyachi America is not responsible for any loss due to improper use of this product.
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HF28 DC RESISTANCE WELDING SYSTEM
990-372 ix
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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 HF28 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.
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HF28 DC RESISTANCE WELDING SYSTEM
990-372 xi
LIMITED WARRANTY
1. (a) Subject to the exceptions and upon the conditions set forth herein, Seller warrants to Buyer that
for a period of one (1) year from the date of shipment (“Warranty Period”), that such Goods will be free
from material defects in material and workmanship.
(b) Notwithstanding the foregoing and anything herein to the contrary, the warranty set forth in this
Section 1 shall be superseded and replaced in its entirety with the warranty set forth on Exhibit A
hereto if the Goods being purchased are specialty products, which include, without limitation, laser
products, fiber markers, custom systems, workstations, Seller-installed products, non-catalogue
products and other custom-made items (each a “Specialty Products.”
(c) EXCEPT FOR THE WARRANTY SET FORTH IN SECTION 1(A), SELLER MAKES NO
WARRANTY WHATSOEVER WITH RESPECT TO THE GOODS (INCLUDING ANY SOFTWARE) OR
SERVICES, INCLUDING ANY (a) WARRANTY OF MERCHANTABILITY; (b) WARRANTY OF
FITNESS FOR A PARTICULAR PURPOSE; (c) WARRANTY OF TITLE; OR (d) WARRANTY
AGAINST INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OF A THIRD PARTY;
WHETHER EXPRESS OR IMPLIED BY LAW, COURSE OF DEALING, COURSE OF
PERFORMANCE, USAGE OF TRADE OR OTHERWISE.
(d) Products manufactured by a third party and third party software (“Third Party Product”) may
constitute, contain, be contained in, incorporated into, attached to or packaged together with, the
Goods. Third Party Products are not covered by the warranty in Section 1(a). For the avoidance of
doubt, SELLER MAKES NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO ANY
THIRD PARTY PRODUCT, INCLUDING ANY (a) WARRANTY OF MERCHANTABILITY; (b)
WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE; (c) WARRANTY OF TITLE; OR (d)
WARRANTY AGAINST INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OF A THIRD
PARTY; WHETHER EXPRESS OR IMPLIED BY LAW, COURSE OF DEALING, COURSE OF
PERFORMANCE, USAGE OF TRADE OR OTHERWISE. Notwithstanding the foregoing, in the event
of the failure of any Third Party Product, Seller will assist (within reason) Buyer (at Buyer’s sole
expense) in obtaining, from the respective third party, any (if any) adjustment that is available under
such third party’s warranty.
(e) Seller shall not be liable for a breach of the warranty set forth in Section 1(a) unless: (i) Buyer gives
written notice of the defect, reasonably described, to Seller within five (5) days of the time when Buyer
discovers or ought to have discovered the defect and such notice is received by Seller during the
Warranty Period; (ii) Seller is given a reasonable opportunity after receiving the notice to examine such
Goods; (iii) Buyer (if requested to do so by Seller) returns such Goods (prepaid and insured to Seller at
1820 South Myrtle Avenue, Monrovia, CA 91016or to such other location as designated in writing by
Seller) to Seller pursuant to Seller’s RMA procedures and Buyer obtains a RMA number from Seller
prior to returning such Goods for the examination to take place; and (iii) Seller reasonably verifies
Buyer’s claim that the Goods are defective and that the defect developed under normal and proper use.
(f)SellershallnotbeliableforabreachofthewarrantysetforthinSection1(a)if:(i)Buyermakesany
furtheruseofsuchGoodsaftergivingsuchnotice;(ii)thedefectarisesbecauseBuyerfailedtofollow
Seller’soralorwritteninstructionsastothestorage,installation,commissioning,useormaintenance
oftheGoods;(iii)BuyeraltersorrepairssuchGoodswithoutthepriorwrittenconsentofSeller;or(iv)
repairsormodificationsaremadebypersonsotherthanSeller’sownservicepersonnel,oran
uthorizedrepresentative’spersonnel,unlesssuchrepairsaremadewiththewrittenconsentofSeller
inaccordancewithproceduresoutlinedbySelleraccordancewithproceduresoutlinedbySeller.
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HF28 DC RESISTANCE WELDING SYSTEM
xii 990-372
(g) All expendables such as electrodes are warranted only for defect in material and workmanship
which are apparent upon receipt by Buyer. The foregoing warranty is negated after the initial use.
(h) Subject to Section 1(e) and Section 1(f) above, with respect to any such Goods during the Warranty
Period, Seller shall, in its sole discretion, either: (i) repair or replace such Goods (or the defective part)
or (ii) credit or refund the price of such Goods at the pro rata contract rate, provided that, if Seller so
requests, Buyer shall, at Buyer’s expense, return such Goods to Seller.
(i) THE REMEDIES SET FORTH IN SECTION 1(H) SHALL BE BUYER’S SOLE AND EXCLUSIVE
REMEDY AND SELLER’S ENTIRE LIABILITY FOR ANY BREACH OF THE LIMITED WARRANTY
SET FORTH IN SECTION 1(A). Representations and warranties made by any person, including
representatives of Seller, which are inconsistent or in conflict with the terms of this warranty, as set
forth above, shall not be binding upon Seller.
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HF28 DC RESISTANCE WELDING SYSTEM
990-372 xiii
Exhibit A
Warranty for “Specialty Products”
Limited Warranty
EXCEPT FOR THE WARRANTY SET FORTH BELOW IN THIS EXHIBIT A, SELLER MAKES NO
WARRANTY WHATSOEVER WITH RESPECT TO THE GOODS (INCLUDING ANY SOFTWARE) OR
SERVICES, INCLUDING ANY (a) WARRANTY OF MERCHANTABILITY; (b) WARRANTY OF
FITNESS FOR A PARTICULAR PURPOSE; (c) WARRANTY OF TITLE; OR (d) WARRANTY
AGAINST INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OF A THIRD PARTY;
WHETHER EXPRESS OR IMPLIED BY LAW, COURSE OF DEALING, COURSE OF
PERFORMANCE, USAGE OF TRADE OR OTHERWISE.
Warranty Period: The Warranty Period for Specialty Products is for one (1) year, and the Warranty
Period for laser welders and laser markers is two (2) years (unlimited hours), and the Warranty Period
for the laser pump diodes or modules is two (2) years or 10,000 clock hours, whichever occurs first (as
applicable, the “Warranty Period”). The Warranty Period begins as follows: (i) on orders for Goods
purchased directly by Buyer, upon installation at Buyer’s site or thirty (30) days after the date of
shipment, whichever occurs first; or (ii) on equipment purchased by a Buyer that is an OEM or systems
integrators, upon installation at the end user’s site or six (6) months after the date of shipment,
whichever occurs first.
Acceptance Tests: Acceptance Tests (when required) shall be conducted at Amada Miyachi
America, Inc., Monrovia, CA, USA (the “Testing Site”) unless otherwise mutually agreed in writing prior
to issuance or acceptance of the Acknowledgement. Acceptance Tests shall consist of a final visual
inspection and a functional test of all laser, workstation, enclosure, motion and accessory hardware.
Acceptance Tests shall include electrical, mechanical, optical, beam delivery, and software items
deliverable under the terms of the Acknowledgement. Terms and conditions for Additional Acceptance
Tests either at Seller’s or Buyer’s facility shall be mutually agreed in writing prior to issuance or
acceptance of the Acknowledgement.
Performance Warranty: The system is warranted to pass the identical performance criteria at Buyer’s
site as demonstrated during final Acceptance Testing at the Testing Site during the Warranty Period, as
provided in the Acknowledgement. Seller explicitly disclaims any responsibility for the process results
of the laser processing (welding, marking, drilling, cutting, etc.) operations.
Exclusions: Seller makes no warranty, express or implied, with respect to the design or operation of
any system in which any Seller’s product sold hereunder is a component.
Limitations: The limited warranty set forth on this Exhibit A does not cover loss, damage, or defects
resulting from transportation to Buyer’s facility, improper or inadequate maintenance by Buyer, Buyer-
supplied software or interfacing, unauthorized modification or misuse, operation outside of the
environmental specifications for the equipment, or improper site preparation and maintenance. This
warranty also does not cover damage from misuse, accident, fire or other casualties of failures caused
by modifications to any part of the equipment or unauthorized entry to those portions of the laser which
are stated. Furthermore, Seller shall not be liable for a breach of the warranty set forth in this Exhibit A
if: (i) Buyer makes any further use of such Goods after giving such notice; (ii) the defect arises because
Buyer failed to follow Seller’s oral or written instructions as to the storage, installation, commissioning,
use or maintenance of the Goods; (iii) Buyer alters or repairs such Goods without the prior written
consent of Seller; or (iv) repairs or modifications are made by persons other than Seller’s own service
personnel, or an authorized representative’s personnel, unless such repairs are made with the written
consent of Seller in accordance with procedures outlined by Seller.

HF28 DC RESISTANCE WELDING SYSTEM
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Seller further warrants that all Services performed by Seller’s employees will be performed in a good
and workmanlike manner. Seller’s sole liability under the foregoing warranty is limited to the obligation
to re-perform, at Seller’s cost, any such Services not so performed, within a reasonable amount of time
following receipt of written notice from Buyer of such breach, provided that Buyer must inform Seller of
any such breach within ten (10) days of the date of performance of such Services.
Seller shall not be liable for a breach of the warranty set forth in this Exhibit A unless: (i) Buyer gives
written notice of the defect or non-compliance covered by the warranty, reasonably described, to Seller
within five (5) days of the time when Buyer discovers or ought to have discovered the defect or non-
compliance and such notice is received by Seller during the Warranty Period; (ii) Seller is given a
reasonable opportunity after receiving the notice to examine such Goods and (a) Buyer returns such
Goods to Seller’s place of business at Buyer’s cost (prepaid and insured); or (b) in the case of custom
systems, Seller dispatches a field service provider to Buyer’s location at Buyer’s expense, for the
examination to take place there; and (iii) Seller reasonably verifies Buyer’s claim that the Goods are
defective or non-compliant and the defect or non-compliance developed under normal and proper use.
All consumable, optical fibers, and expendables such as electrodes are warranted only for defect in
material and workmanship which are apparent upon receipt by Buyer. The foregoing warranty is
negated after the initial use.
No warranty made hereunder shall extend to any product whose serial number is altered, defaced, or
removed.
Remedies: With respect to any such Goods during the Warranty Period, Seller shall, in its sole
discretion, either: repair such Goods (or the defective part). THE REMEDIES SET FORTH IN THE
FOREGOING SENTENCE SHALL BE BUYER’S SOLE AND EXCLUSIVE REMEDY AND SELLER’S
ENTIRE LIABILITY FOR ANY BREACH OF THE LIMITED WARRANTY SET FORTH IN THIS
EXHIBIT A. Representations and warranties made by any person, including representatives of Seller,
which are inconsistent or in conflict with the terms of this warranty, as set forth above, shall not be
binding upon Seller.
Products manufactured by a third party and third party software (“Third Party Product”) may
constitute, contain, be contained in, incorporated into, attached to or packaged together with, the
Goods. Third Party Products are not covered by the warranty in this Exhibit A. For the avoidance of
doubt, SELLER MAKES NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO ANY
THIRD PARTY PRODUCT, INCLUDING ANY (a) WARRANTY OF MERCHANTABILITY; (b)
WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE; (c) WARRANTY OF TITLE; OR (d)
WARRANTY AGAINST INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OF A THIRD
PARTY; WHETHER EXPRESS OR IMPLIED BY LAW, COURSE OF DEALING, COURSE OF
PERFORMANCE, USAGE OF TRADE OR OTHERWISE. Notwithstanding the foregoing, in the event
of the failure of any Third Party Product, Seller will assist (within reason) Buyer (at Buyer’s sole
expense) in obtaining, from the respective third party, any (if any) adjustment that is available under
such third party’s warranty.
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HF28 DC RESISTANCE WELDING SYSTEM
990-372 1-1
CHAPTER 1
Description
Section I: Features
Features
For the rest of this manual, the Miyachi Unitek HF28 High Frequency Resistance Welding System
control will simply be referred to as the Control.
NOTE: This manual describes HF28 Models 1-310-01, 1-310-01-01, 1-310-01-02 manufactured after
June 2005. These contain significant differences than earlier models. HF28 models 1-288-01 and 1-288-
01-01 manufactured before June 2005 require a different manual.
For information on getting that manual, use the phone number or e-mail address listed under Contact Us
in the front of this manual.
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 (40 microseconds)
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.
HF28 Front Panel

CHAPTER 1: DESCRIPTION
HF28 DC RESISTANCE WELDING SYSTEM
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You can program the Control from the front
panel, using simplified key clusters and on-
screen data fields. A MAIN MENU screen
allows you select all of the system setup
options for working with inputs from
external equipment.
<MAIN MENU>
1.SETUP 6.RELAY
2. WELD COUNTERS 7. RESET DEFAULTS
3. COPY A SCHEDULE 8. CHAIN SCHEDULES
4. CALIBRATION
5. SYSTEM SECURITY
Number Select an item
The RUN screen allows you to easily modify
any time period, current, voltage, or power
value.
Run Screen
The MONITOR screen provides instant visual
feedback on the actual current, voltage, or
power used to make each weld. It permits
you to program adjustable limits for both
weld pulses.
Monitor Screen
Rear-mounted RS-232 is for uploading software revisions
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.

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

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

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

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Front Panel Data Entry and Mode Keys
Key Pad
The keypad consists of the numeric keys and the up/down/left/right 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.
The 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. Used to terminate program
mode if already in the RUN screen.
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