Amada Miyachi Unitek STA-200A User manual

990-351 Rev H
AC WELDER
STA SERIES
OPERATION MANUAL
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

STA SERIES AC CONTROLS
ii 990-351
Copyright © 2001, 2002, 2014 Amada Miyachi America
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 .
Printed in the United States of America
Revision Record
Revision EO Date Basis of Revision
A 19123 12/01 Initial Release
B 19373 7/02
Addition of technical upgrades and features and inclusion of other
STA models.
C 19557 11/02
Inclusion of all STA Controls, and software upgrade to version
3.0.
D 20369 3/05 Updated technical information.
E 21467 7/07 Updated Schematics.
F 42840 10/13 Updated to Miyachi America name and logo.
G 43479 11/14 Updated to Amada Miyachi America name and logo.
H 43808 8/15 Updated to Amada Miyachi format, deleted obsolete models.

STA SERIES AC CONTROLS
990-351 iii
CONTACT US
Thank you for purchasing a Miyachi Unitek STA Series AC Control. This
unit is a component of a larger resistance welding system. Upon receipt,
please inspect it thoroughly for shipping damage before you install it. If
there is any damage, contact the shipping company immediately 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]
Amada Miyachi America is not responsible for any losses due to improper
use of this product. The contents of this manual are subject to change
without notice. If you have any questions, find any errors/omissions, or if
you have suggestions for improving this manual, please contact us.
About This Equipment
The Control consists of a cabinet which contains the AC Main Timer
Board, SCR Driver Board, Control Panel Assembly, valve and power
transformers; SCR assemblies and snubbers and surge resistors. Unless
ordered otherwise, STA-200 Controls contain a circuit breaker that
disconnects when the front panel is opened. Four tabs on the rear surface
provide convenient mounting of the unit. The Control provides the user
with all of the controls for establishing all weld modes and timing.
Control options include a Valve Expansion Board, communication
capability, voltage monitoring, electronic pressure regulator control, force
monitoring and either primary current sensor or input connector(s) for
secondary current sensor(s). WeldLab software to extract and analyze
weld data is also available.
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.

STA SERIES AC CONTROLS
iv 990-351
SAFETY NOTES
This instruction manual describes how to operate, maintain and service STA Series AC Controls, and
provides instructions relating to their SAFE use.
For SAFETY, and to effectively take advantage of the full capabilities of the workstation, please read
these instructions before attempting to use the workstation.
Procedures other than those described in this manual or not performed as prescribed in it, may expose
personnel to electrical hazards.
After reading this manual, retain it for future reference when any questions arise regarding the proper
and SAFE operation of the unit.
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.
WARNINGS
HIGH VOLTAGE is used in the operation of this equipment.
DEATH ON CONTACT may result if personnel fail to observe the
safety precautions labeled on the equipment and noted in this manual.
WHEN WELDING always wear safety glasses.

STA SERIES AC CONTROLS
990-351 v
CONTENTS Page
Revision Record ......................................................................................................................................... ii
Contact Us ..............................................................................................................................................iii
Safety Notes .............................................................................................................................................. iv
Chapter 1. Description
Section I: Features ..................................................................................................................................1-1
Overview ..........................................................................................................................................1-1
Standard Features .............................................................................................................................1-1
Optional Features .............................................................................................................................1-1
Section II: Major Components ................................................................................................................1-3
Major Components ..........................................................................................................................1-3
Front Panel Controls and Indicators ................................................................................................1-5
LCD Display .............................................................................................................................1-5
Ready ........................................................................................................................................1-5
Error ..........................................................................................................................................1-5
Weld .........................................................................................................................................1-5
Start ...........................................................................................................................................1-5
Program/Save ...........................................................................................................................1-5
Weld ON/OFF ..........................................................................................................................1-6
Data + ON | OFF ......................................................................................................................1-6
Cursor .......................................................................................................................................1-6
Schedule ...................................................................................................................................1-6
Valves .......................................................................................................................................1-6
Modes .......................................................................................................................................1-7
Reset .........................................................................................................................................1-7
Monitor .....................................................................................................................................1-7
Stepper ......................................................................................................................................1-7
Programming Lock ...................................................................................................................1-7
External Connectors .........................................................................................................................1-7
Cylinder Air Hose Connections ....................................................................................................... 1-8
Internal Access .................................................................................................................................1-8
Option Cards ....................................................................................................................................1-9
Electrical Connections .....................................................................................................................1-9
Chapter 2. Installation and Setup
Section I: Planning for Installation ..........................................................................................................2-
1
Environmental Factors .....................................................................................................................2-1
Space and Mounting Requirements .................................................................................................2-1
Power Requirements ........................................................................................................................2-1
Cooling Water Requirements .........................................................................................................2-1

STA SERIES AC CONTROLS
vi 990-351
CONTENTS (Continued) Page
Section II: Control Set-up ......................................................................................................................2-2
Unpacking ........................................................................................................................................2-2
Installation .......................................................................................................................................2-2
Mounting the Control ......................................................................................................................2-2
Connecting Electrical Power ...........................................................................................................2-2
Secondary Current Sensing ..............................................................................................................2-3
Placement of Secondary Current Coils .....................................................................................2-3
Valve Transformer Wiring Connections ..................................................................................2-3
Cooling Water Hose Connections ...................................................................................................2-3
Input/Output Signal Connections ....................................................................................................2-3
Chapter 3. Using STA Series Control Functions
Section I: Overview ............................................................................................................................... 3-1
Section II: Schedule Screen ...................................................................................................................3-2
SCHEDULE # ................................................................................................................................3-2
PROGRAM/SAVE ..........................................................................................................................3-2
Links ............................................................................................................................................3-2
SQD (Squeeze Delay) ......................................................................................................................3-2
SQZ (Squeeze Time) .......................................................................................................................3-2
UP1 (Weld 1 Upslope Time) ...........................................................................................................3-2
W1 (Weld 1 Time) ...........................................................................................................................3-2
DN1 (Weld 1 downslope time) ........................................................................................................3-3
CO (cool time) .................................................................................................................................3-3
UP2 (Weld 2 Upslope Time) ...........................................................................................................3-3
W2 (Weld 2 Time) ...........................................................................................................................3-3
DN2 (Weld 2 Downslope Time) ......................................................................................................3-3
HLD –hold time ...............................................................................................................................3-3
OFF ............................................................................................................................................3-3
MODE ............................................................................................................................................3-3
CURRENT SETTING .....................................................................................................................3-3
CH (Force Output Channel) .............................................................................................................3-3
FORCE ...........................................................................................................................................3-3
ElecValve (Valve Associated with Electrode) ................................................................................3-3
SCR # (SCR Number) .....................................................................................................................3-3
IMPULSE (Quantity of Weld 2 Operations) ...................................................................................3-3
COPY TO # – Copying a schedule .................................................................................................3-4
Section III: Valves Screen .....................................................................................................................3-5
SCHEDULE # .................................................................................................................................3-5
PROGRAM/SAVE ..........................................................................................................................3-5
ELECTRODE VALVE .................................................................................................................... 3-5
STATUS ..........................................................................................................................................3-5
COUNT ............................................................................................................................................3-5

STA SERIES AC CONTROLS
990-351 vii
Page
Section IV: Monitor Screen ...................................................................................................................3-6
CURR (Weld Current) .....................................................................................................................3-6
COND (Conduction Angle) .............................................................................................................3-6
VOLTS ............................................................................................................................................3-6
FORCE(LBS) ..................................................................................................................................3-6
LO (Low Current Limit) .................................................................................................................. 3-6
HI (High Current Limit) ..................................................................................................................3-6
COND. LIMIT (Conduction Angle Limit) ......................................................................................3-7
Counts (MONITOR COUNTS Screen) ......................................................................................3-7
Section V: Monitor Counts Screen ........................................................................................................3-8
SCHEDULE # (Schedule number) ..................................................................................................3-8
WELD COUNT ...............................................................................................................................3-8
WELD COUNT LIMIT ...................................................................................................................3-8
SET WELD COUNT = 0 .................................................................................................................3-8
STEP # (Step Number) ....................................................................................................................3-8
STEP COUNT .................................................................................................................................3-8
ELECT. VALVE .............................................................................................................................3-8
STEP COUNT .................................................................................................................................3-8
ELECT. VALVE .............................................................................................................................3-8
Section VI: Mode Screen .......................................................................................................................3-9
SCHEDULE # (Schedule Number) ................................................................................................3-9
PROGRAM/SAVE ..........................................................................................................................3-9
START ............................................................................................................................................3-9
WELD MODE .............................................................................................................................. 3-10
Spot Weld Mode .....................................................................................................................3-10
Repeat Mode ...........................................................................................................................3-10
Successive Mode ....................................................................................................................3-10
Chaining Mode .......................................................................................................................3-10
LINKED SCHED .......................................................................................................................3-11
Section VII: Linked Schedules Screen ................................................................................................3-12
Reference .......................................................................................................................................3-12
SCHD ..........................................................................................................................................3-12
CURR WELD CNT (Weld Counts for Schedule) .........................................................................3-12
WELD MODE ...............................................................................................................................3-12
ERROR ..........................................................................................................................................3-12
Section VIII: System Values Screens ..................................................................................................3-13
System Values Screen 1 .................................................................................................................3-13
FULL CURR. (Full Current) ..................................................................................................3-13
MAX # OF SCR (SCRs in Control) .......................................................................................3-13
TURNS RATIO ......................................................................................................................3-13

STA SERIES AC CONTROLS
viii 990-351
CONTENTS (Continued) Page
CNTRL MODE (Control Mode) ............................................................................................3-13
BIN. SCHED. SELECT (Binary Schedule Select) ................................................................3-13
FIRING SWITCH ..................................................................................................................3-13
COIL .......................................................................................................................................3-13
CONTRAST+/– ......................................................................................................................3-13
NUM VALVES (Number of Valves)......................................................................................3-14
VALVES STATUS ................................................................................................................3-14
MODE ....................................................................................................................................3-14
MORE (System Value Screen 2) ............................................................................................3-14
System Values Screen 2 .................................................................................................................3-14
87° DELAY (ON or OFF) ......................................................................................................3-14
END OUTPUT .......................................................................................................................3-14
STEP END OUTPUT .............................................................................................................3-14
WELD ON/OFF .....................................................................................................................3-14
LOW LINE ALARM ............................................................................................................3-14
AUTO RESET ........................................................................................................................3-14
ERROR OUTPUT ..................................................................................................................3-15
SET DEFAULTS ....................................................................................................................3-15
MASTER CNTL ....................................................................................................................3-15
UNIT ADDRESS ....................................................................................................................3-15
System Values Screen 3 .................................................................................................................3-15
RETRACTION .......................................................................................................................3-15
Pressure Switch ......................................................................................................................3-16
Output Force ...........................................................................................................................3-16
Monitored Volts ..............................................................................................................3-16
Monitored Time ...............................................................................................................3-16
Back Pressure .........................................................................................................................3-16
Screen 2 ...............................................................................................................................3-16
Section IX. System Valve Status Screen ............................................................................................. 3-17
VALVE (Valve Numbers) ......................................................................................................3-17
CNT (Weld Count) .................................................................................................................3-17
RESET (Reset Count to Zero) ................................................................................................ 3-17
SCR (SCR Used With Each Valve) ........................................................................................3-17
Section X: Force Calibration Screen ....................................................................................................3-18
Section XI. Stepper Screen ..................................................................................................................3-19
VALVE NUM ...............................................................................................................................3-19
SCR# (SCR Number) ...................................................................................................................3-19
STEPPER (ON/OFF) ....................................................................................................................3-19
COUNT ..........................................................................................................................................3-19
HEAT% .........................................................................................................................................3-19

STA SERIES AC CONTROLS
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Page
Chapter 4. Operating Instructions
Section I: Introduction ........................................................................................................................... 4-1
Overview ..........................................................................................................................................4-1
General Operator Safety ..................................................................................................................4-1
Section II: Preparing for Operation ........................................................................................................4-2
Turning the Equipment ON .............................................................................................................4-2
Pre-Operational Setup ......................................................................................................................4-3
Section III: Setup Messages ....................................................................................................................4-4
Section IV. Operation ............................................................................................................................ 4-6
Spot Welds .......................................................................................................................................4-7
Continuous Seam Weld ...................................................................................................................4-8
Cascading (Multiple SCRs) .............................................................................................................4-9
Section V: Operational Messages ........................................................................................................4-11
Major Run-Time Error Messages ..................................................................................................4-11
Minor Run-Time Error Messages ..................................................................................................4-13
Section VI: Shutdown ..........................................................................................................................4-15
Emergency Shutdown ....................................................................................................................4-15
Normal Shutdown ..........................................................................................................................4-15
Chapter 5. Maintenance
Section I: Precautions ............................................................................................................................5-1
Section II: General Information .............................................................................................................5-1
General Maintenance Procedures ....................................................................................................5-1
Cooling Maintenance – Water Draining ..........................................................................................5-1
Fuse Replacement ............................................................................................................................5-2
Principles of Operation ....................................................................................................................5-2
Wiring Diagram ...............................................................................................................................5-3
Section III. Standard Components Replacement ...................................................................................5-5
AC Timer Main Board .....................................................................................................................5-5
Power Transformer T1 .....................................................................................................................5-7
Power Transformer T2 .....................................................................................................................5-7
Valve Transformer, T3 ....................................................................................................................5-7
Surge Resistors ...............................................................................................................................5-7
Snubber ............................................................................................................................................5-8
SCR Drive Board .............................................................................................................................5-8
Control Panel Assembly ..................................................................................................................5-9
Section IV. Optional Components Replacement .................................................................................5-10
Optional Primary Current Sensor ..................................................................................................5-10
Optional Secondary Current Sensor Connector .............................................................................5-10
Optional Key Lock ........................................................................................................................5-11
Optional SCR Assembly, 600,1200, 1800, and 2200 Amp ........................................................... 5-11

STA SERIES AC CONTROLS
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CONTENTS (Continued) Page
Section V. Spare Parts ..........................................................................................................................5-12
Section VI. Repair ................................................................................................................................5-13
Section VII. Storage and Shipment ......................................................................................................5-13
Preparation for Storage or Shipment .............................................................................................5-13
Packing for Storage or Shipment ................................................................................................... 5-13
Appendix A. Technical Specifications ............................................................................................... A-1
Appendix B. Electrical And Data Connections .................................................................................B-1
Appendix C. SCR, Wire Gauge, And Circuit Breaker Selection ....................................................C-1
Appendix D. System Timing .............................................................................................................. D-1
Appendix E. Cascade Option ..............................................................................................................E-1
Appendix F. Valve Expansion Board Option ....................................................................................F-1
Appendix G. Voltage Monitor Board Option ................................................................................... G-1
Appendix H. Force Control Option.................................................................................................... H-1
Appendix I. Pressure Control Option..................................................................................................I-1
Appendix J. Communications ..............................................................................................................J-1
Appendix K. Circuit Modification for External Transformer Thermostat .................................. K-1
Appendix L. Default Initializations ....................................................................................................L-1
Index .....................................................................................................................................Index-1