Miyachi STA-100A Manual

USER’S MANUAL NO. 990-350
REVISION E: January 2002
OPERATION, MAINTENANCE
AND SERVICE MANUAL
FOR THE
STA-100A
AC CONTROL
Version 2.11 Software

STA-100A AC CONTROL
ii 990-350
Copyright © 2000, 2002, 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
18147
3/00
Pre-production release
B
18533
11/00
Production Release
C
18677
1/01
Version 1.3 Release
D
19039
8/01
Version 2.0 Release
E
19181
1/02
Version 2.11 Release

STA-100A AC CONTROL
990-350 iii
FOREWORD
Thank you for purchasing a Miyachi STA-100A AC Control. This unit is a component of a larger resistance
welding system.
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:
Miyachi
245 E. El Norte St.
P.O. Box 5039
Monrovia, CA 91017
Telephone: [phone]
FAX: [phone]
e-mail: [e-mail]
The purpose of this manual is to supply operating and maintenance personnel with the information needed
to properly and safely operate and maintain Miyachi's STA-100A AC Control.
The Control consists of a cabinet which contains the AC Main Timer Board, A1; SCR Driver Board, A2;
Control Panel Assembly, A3; Valve Expansion Board, A4 (optional); valve and power transformers; SCR
assembly and snubber; surge resistors, and either primary current sensor or input connector for secondary
current sensor (optional). Except for the 300A SCR model, the Control is capable of being mounted either
on its left side or rear (from the perspective of the control panel). The 300A SCR model can only be
mounted on its left side. The Control provides the user with all of the controls for establishing all weld
modes and timing.
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.

STA-100A AC CONTROL
iv 990-350
SAFETY NOTES
This instruction manual describes how to operate, maintain and service the STA-100A AC Timer, and
provides instructions relating to its 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-100A AC CONTROL
990-350 v
CONTENTS
CHAPTER 1: Description.................................................................................................................... 1-1
Section I: Features....................................................................................................................... 1-1
Section II: Major Components.................................................................................................... 1-1
Major Components........................................................................................................... 1-1
Controls and Indicators.................................................................................................... 1-3
Internal Access................................................................................................................. 1-5
Mounting Holes ............................................................................................................... 1-5
Electrical Connections..................................................................................................... 1-5
Water Connections........................................................................................................... 1-5
CHAPTER 2: Getting Started............................................................................................................. 2-1
Section I: Planning for Installation............................................................................................. 2-1
Environmental Factors..................................................................................................... 2-1
Space and Mounting Requirements................................................................................. 2-1
Power Requirements........................................................................................................ 2-1
Cooling Water Requirements (600 and 1200 Amp Controls Only) ................................ 2-1
Section II: Control Set-up........................................................................................................... 2-2
Unpacking........................................................................................................................ 2-2
Installation........................................................................................................................ 2-2
Mounting the Control........................................................................................... 2-2
Electrical Connections......................................................................................... 2-3
Secondary Current Sensor.................................................................................... 2-4
Cooling Water Hose Connections........................................................................ 2-4
Input/Output Signal Connections......................................................................... 2-4
Input/Output Signal Descriptions ........................................................................ 2-6
CHAPTER 3: Operating Instructions ................................................................................................ 3-1
Section I: Operating Precautions .............................................................................................. 3-1
General Operator Safety .................................................................................................. 3-1
Section II: Preparing for Operation............................................................................................ 3-1
Turning the Equipment On .............................................................................................. 3-1
Pre-Operational Setup...................................................................................................... 3-2
Schedule Screen................................................................................................... 3-2
System Wide Values Screen................................................................................ 3-7
Extended System Wide Values Screen................................................................ 3-8
System Valve Status Screen................................................................................. 3-10
Valve Screen........................................................................................................ 3-10
Mode Screen ........................................................................................................ 3-11
Linked Schedules Screen..................................................................................... 3-14
Monitor Screen..................................................................................................... 3-15
Stepper Screen ..................................................................................................... 3-16

STA-100A AC CONTROL
vi 990-350
Section III: Setup Messages...................................................................................................... 3-18
Section IV: Operation................................................................................................................ 3-21
Section V: Programming Examples......................................................................................... 3-22
Spot Welds....................................................................................................................... 3-22
Continuous Seam Weld.................................................................................................... 3-23
Section VI: Operational Messages............................................................................................. 3-24
Major Run-Time Error Messages .................................................................................... 3-24
Minor Run-Time Error Messages.................................................................................... 3-27
Section VII: Shutdown................................................................................................................ 3-29
Emergency Shutdown...................................................................................................... 3-29
Normal Shutdown............................................................................................................ 3-29
CHAPTER 4: User Maintenance ........................................................................................................ 4-1
Section I: Maintenance Precautions............................................................................................ 4-1
Precautions....................................................................................................................... 4-1
Section II: Maintenance Procedures ........................................................................................... 4-1
Cooling Maintenance....................................................................................................... 4-1
Heat Sink Cleaning (300 Amp SCR Unit Only).................................................. 4-1
Water Draining (600 and 1200 Amp SCR Units Only)....................................... 4-1
Fuse Replacement............................................................................................................ 4-1
CHAPTER 5: Service........................................................................................................................... 5-1
Section I: Service Precautions .................................................................................................... 5-1
Precautions....................................................................................................................... 5-1
Section II: Service Procedures.................................................................................................... 5-1
Principles of Operation.................................................................................................... 5-1
Fuse Replacement............................................................................................................ 5-2
Components Replacement ............................................................................................... 5-2
General Repair Instructions ................................................................................. 5-2
AC Timer Main Board, A1.................................................................................. 5-2
SCR Driver Board, A2......................................................................................... 5-4
Control Panel Assembly, A3................................................................................ 5-5
Valve Expansion Board, A4 (Optional)............................................................... 5-6
Valve Transformer, T3......................................................................................... 5-6
Power Transformer, T2........................................................................................ 5-7
Power Transformer, T1........................................................................................ 5-7
Surge Resistors .................................................................................................... 5-8
Snubber ............................................................................................................... 5-8
L2 Terminal Block (Optional)............................................................................. 5-8
Ground Terminal Block....................................................................................... 5-8
Primary Current Sensor (Optional)...................................................................... 5-9
Secondary Current Sensor Connector (Optional)................................................ 5-9
Key Lock (Optional)............................................................................................ 5-9
SCR Assembly, 300 Amp, Air Cooled (Optional) .............................................. 5-10
SCR Assembly, 600 and 1200 Amp, Water Cooled (Optional).......................... 5-10
Spare Parts Kit ................................................................................................................. 5-13
Section III: Repair Service.......................................................................................................... 5-13

STA-100A AC CONTROL
990-350 vii
Section IV: Storage and Shipment.............................................................................................. 5-13
Preparation for Storage or Shipment................................................................................ 5-13
Packaging for Storage or Shipment ................................................................................. 5-13
APPENDIX A: Technical Specifications ............................................................................................ A-1
APPENDIX B: System Timing............................................................................................................ B-1
APPENDIX C: SCR, Wire Size, and Circuit Breaker Selection...................................................... C-1
APPENDIX D: Circuit Modification for External Transformer Thermostat................................ D-1
APPENDIX E: Default Initializations................................................................................................. E-1
INDEX.................................................................................................................................................. Index-1
ILLUSTRATIONS
Figure Title Page
1-1 STA-100A AC Control, Major Components............................................................................... 1-2
1-2 Controls and Indicators................................................................................................................ 1-3
2-1 Installing Mounting Tabs onto Cabinet ....................................................................................... 2-2
2-2 Power Connection Points............................................................................................................. 2-3
2-3 Placement of Secondary Current Sensor Toroidal Coil............................................................... 2-4
2-4 Wiring Connections to Valve (Input Power) Transformer .......................................................... 2-4
2-5 Input/Output Control Signals....................................................................................................... 2-5
2-6 Valve Expansion Board, A4, Input/Output Signals..................................................................... 2-7
3-1 Control Panel with Introductory Screen and Indicators............................................................... 3-1
3-2 Typical Initial Schedule Screen ................................................................................................... 3-2
3-3 Typical Second Schedule Screen................................................................................................. 3-3
3-4 Typical Third Schedule Screen.................................................................................................... 3-3
3-5 Schedule Screen with Percent Heat and Percent Heat Secondary............................................... 3-5
3-6 Schedule Screen Primary Constant Current Mode ...................................................................... 3-5
3-7 Schedule Screen Secondary Constant Current Mode .................................................................. 3-5
3-8 System Wide Values Screen........................................................................................................ 3-7
3-9 Extended System wide Values Screen......................................................................................... 3-8
3-10 System Valve Status Screen......................................................................................................... 3-9
3-11 Valve Screen .............................................................................................................................. 3-10
3-12 Mode Screen .............................................................................................................................. 3-11
3-13 Linked Schedules Screen............................................................................................................. 3-14
3-14 Monitor Screen............................................................................................................................. 3-15
3-15 Stepper Screen ............................................................................................................................. 3-17
3-16 Example of Stepper Function....................................................................................................... 3-17
5-1 Control, Simplified Block Diagram............................................................................................. 5-1
5-2 AC Timer Main Board, A1, Connector Locations....................................................................... 5-3
5-3 SCR Driver Board, A2, Connector Locations ............................................................................. 5-4
5-4 Control Panel Assembly, A3, Connector Locations.................................................................... 5-5
5-5 Valve Expansion Board, A4, (Optional) Connector Locations ................................................... 5-6
5-6 Control, Wiring Diagram............................................................................................................. 5-12

STA-100A AC CONTROL
viii 990-350
TABLES
Table Title Page
4-1 Valve Transformer Fuse Selection............................................................................................... 4-1
5-1 Spare Parts Kit, 4-35732-01......................................................................................................... 5-13

STA-100A AC CONTROL
990-350 1-1
CHAPTER 1
DESCRIPTION
Section I: Features
The STA-100A AC Control, herein called the “Control,” is a device for controlling single-phase AC
welding. It has the following features:
•Multiple pulse capability
•Controlled current ramps
•300, 600, or 1200 amp SCRs with constant current control
•Air (300 amp) or water (600, 1200 amp) cooling of the SCR assembly
•Programming features with LCD display
•Programmable for spot, repeat, successive, or chaining modes
•Continuous seam weld and roll spot seam welding capabilities (optional)
•Programmable for 64 welding schedules and four pressure valve signals
•Valve drivers for up to four valves are included in the basic unit. A Valve Driver Expansion card is
an optional add-on to increase valve-driver capability to 12 valves.
Section II: Major Components
Major Components
The Control is contained in a 18” x 10” x 10” enclosure. Specific dimensions, weight, and locations of
mounting are shown in Chapter 2, Getting Started, and Appendix A, Specifications. Access to the
internal components is gained by opening the hinged side panel, which is secured with two quarter-turn
screw fasteners. The access panel can be locked closed by a key. When open, the panel can be lifted
from the hinges to facilitate installation and maintenance. The major components of the 300A and
600A/1200A units are indicated in the several views comprising figure 1-1.

CHAPTER 1: DESCRIPTION
STA-100A AC CONTROL
1-2 990-350
Components of Control with 300A (Air Cooled) SCR and Primary Current Sensor
Components of Control with 300A (Air
Cooled) SCR and Connector for
Secondary Current Sensor Input
Components of Control with
600A/1200A (Water Cooled) SCR and
Primary Current Sensor
Chassis
Ground
T3
Valve
Trans-
former
A2
SCR
Drive
Board
Key
Switch
A3
Control
Panel
Assy
300 Amp
SCR
Air
Cooling
Fins
Primary
Current
Sensor
SOL
SR1
SR2
1
21 2
H2-1
Valve
Expander
Board, A4
(Optional)
AC Timer
Main Board, A1
Surge
Resistors
Push
Solenoid
Power
Transformers
CT1
Primary
Current
Sensor
300 Amp
(Air Cooled)
SCR
T3
Valve
Transformer
T2
T1
L2
Chassis
Ground
T3
Valve
Transformer CT1
Secondary
Current Sensor
Input Connector
SN1
Snubber SCR1
300 Amp
SCR
H1-1
L1
Chassis
Ground
T3
Valve
Trans-
former
CT1
Primary
Current Sensor
SN1
Snubber
SCR1
600/1200
Amp SCR
H1-1
L1
Figure 1-1. STA-100A AC Control, Major Components
Figure 1-1. STA-100A AC Control, Major Components
Access Panel Side