Miyachi Unitek 250DPS User manual

USER'S MANUAL 990-280
Revision H March 2004
250DP DUAL PULSE
STORED ENERGY RESISTANCE WELDING
POWER SUPPLIES
Model Stock No.
250DP 1-250-XX
250DP/208 1-250-XX-01
250DP/230 1-250-XX-02
250DP/100 1-250-XX-03
250DPS 1-254-XX
250DPS/208 1-254-XX-01
250DPS/230 1-254-XX-02
250DPS/100 1-254-XX-03
NOTE: Units with the built-in Weld Sentry
Option also require User's Manual No. 990-291.

MODEL 250DP DUAL PULSE
RESISTANCE WELDING POWER SUPPLY
ii 990-280
Copyright © 1998, 2002, 2004 Miyachi Unitek Corporation
The engineering designs, drawings and data contained herein are the proprietary work of
MIYACHI UNITEK CORPORATION and may not be reproduced, copied, exhibited or
otherwise used without the written authorization of MIYACHI UNITEK CORPORATION.
Printed in the United States of America.
Revision Record
Revision EO Date Basis of Revision
A ENRG-RLSE 1/94
Released Original Manual.
B 17215 11/97
ƔReorganize data and update format.
ƔIncorporate Addendum 995-280, Rev A
(10/97); and Errata 996-280, Rev B.
C 17405 4/98
Add operating features.
D 17574 6/98
Correct Test Point designation.
E 18282 5/00
ƔAdd CAUTION statement about polarity in
chained weld schedules.
ƔAdd Declaration of Conformity.
F 18577 11/00
ƔAdd tolerance to pulse output voltage.
ƔClarify operation of relay outputs.
G 19146 01/02
Complete Update
H 20002 3/04
Updated Schematics. Minor formatting changes.

MODEL 250DP DUAL PULSE
RESISTANCE WELDING POWER SUPPLY
990-280 iii
CONTENTS
Revision Record ......................................................................................................................................... ii
Contents .................................................................................................................................................... iii
Contact Us ................................................................................................................................................. ix
Safety Notes ................................................................................................................................................x
Declaration of Conformity ........................................................................................................................ xi
CHAPTER 1: SYSTEM DESCRIPTION ....................................................................................... 1-1
Applications .................................................................................................................................... 1-1
Features ....................................................................................................................................... 1-2
CHAPTER 2: INSTALLATION ...................................................................................................... 2-1
Location ....................................................................................................................................... 2-1
Power Line...................................................................................................................................... 2-1
Welding Cables............................................................................................................................... 2-1
Rear Panel Components.................................................................................................................. 2-3
Firing Switch Connections.............................................................................................................. 2-4
Mechanical Firing Switch ......................................................................................................... 2-4
Optical Firing Switch................................................................................................................ 2-4
3 Wire Firing Switches ............................................................................................................. 2-4
Air Actuated Weld Head Connections............................................................................................ 2-5
Air Valve Driver ....................................................................................................................... 2-6
Non Miyachi Unitek Air Actuated Weld Heads ....................................................................... 2-7
Air Actuated Weld Heads without Force Firing Switches........................................................ 2-7
Second Air Head ....................................................................................................................... 2-7
Footswitch....................................................................................................................................... 2-7
1-Level Footswitch ................................................................................................................... 2-7
2-Level Footswitch ................................................................................................................... 2-8
Remote Schedule Selection............................................................................................................. 2-8
Relay Outputs.................................................................................................................................. 2-8
Interconnection Diagram ................................................................................................................ 2-9
CHAPTER 3: OPERATING CONTROLS AND SCREENS........................................................ 3-1
Operating Controls.......................................................................................................................... 3-1
Screen Formats................................................................................................................................ 3-3

MODEL 250DP DUAL PULSE
RESISTANCE WELDING POWER SUPPLY
iv 990-280
CHAPTER 4: GETTING STARTED .............................................................................................. 4-1
Powering Up ................................................................................................................................... 4-1
Adjusting an Air Actuated Weld Head ........................................................................................... 4-1
CHAPTER 5: OPERATING INSTRUCTIONS ............................................................................. 5-1
Successful Welding......................................................................................................................... 5-1
Resistance Welding Parameters...................................................................................................... 5-1
Weld Schedule Development.......................................................................................................... 5-1
Weld Head Parameters.............................................................................................................. 5-2
250DP Power Supply Parameters ............................................................................................. 5-4
Making a Weld................................................................................................................................ 5-4
Evaluating the Weld........................................................................................................................ 5-4
Weak Weld................................................................................................................................ 5-5
Electrode Sticking..................................................................................................................... 5-5
Causes of Imperfect Welds ............................................................................................................. 5-5
Electrode Force and %Energy .................................................................................................. 5-5
Polarity...................................................................................................................................... 5-6
Weld Strength Profiles.................................................................................................................... 5-7
Destructive Testing ......................................................................................................................... 5-7
Electrode Maintenance.................................................................................................................... 5-8
CHAPTER 6: PROCESS DEFINITIONS AND WELD FUNCTIONS ....................................... 6-1
250DP States................................................................................................................................... 6-1
RUN State ................................................................................................................................. 6-1
STANDBY State....................................................................................................................... 6-2
PROGRAM State...................................................................................................................... 6-2
MENU State.............................................................................................................................. 6-3
HELP State................................................................................................................................ 6-4
NO WELD State ....................................................................................................................... 6-4
FIRE State................................................................................................................................. 6-4
Weld Function Field ....................................................................................................................... 6-4
Basic Function .......................................................................................................................... 6-5
Repeat Function ........................................................................................................................ 6-6
Rollspot Function...................................................................................................................... 6-7
CHAPTER 7: MAINTENANCE ...................................................................................................... 7-1
Modification and Calibration.......................................................................................................... 7-1
Cover Removal ......................................................................................................................... 7-1
Capacitor Bank Modifications .................................................................................................. 7-1

MODEL 250DP DUAL PULSE
RESISTANCE WELDING POWER SUPPLY
990-280 v
Line Voltage Changes ................................................................................................................. 7-2
Calibration ................................................................................................................................... 7-8
Troubleshooting .............................................................................................................................. 7-10
Repair Service ................................................................................................................................. 7-11
Telephone Service ..................................................................................................................... 7-11
Factory Service Repair .............................................................................................................. 7-11
APPENDIX A: TECHNICAL SPECIFICATIONS .......................................................................A-1
250DP Power Supply .....................................................................................................................A-1
Power Requirements ......................................................................................................................A-1
Capacitor Bank ...............................................................................................................................A-1
Output Pulse Characteristics ....................................................................................................A-1
Weld Fire Lockout ...................................................................................................................A-2
Line Voltage Regulation ..........................................................................................................A-2
Turndown Circuit .....................................................................................................................A-2
Line Failure Turndown ............................................................................................................A-2
Over-Voltage Lockout .............................................................................................................A-3
Charge Lockout Circuit ............................................................................................................A-3
Polarity Selection ...........................................................................................................................A-3
Welding Speed ...............................................................................................................................A-3
Weld Schedules ..............................................................................................................................A-6
Weld Schedule Definition ........................................................................................................A-6
Options .......................................................................................................................................A-6
Schedule Number at Power-Up ...............................................................................................A-7
Utilities ......................................................................................................................................A-7
Information ....................................................................................................................................A-7
Weld Sentry ...................................................................................................................................A-7
System Set-up ................................................................................................................................A-8
Weld Functions ..............................................................................................................................A-8
Head Type ......................................................................................................................................A-8
Squeeze Line ............................................................................................................................A-8
Cool Time ................................................................................................................................A-9
Hold Time ................................................................................................................................A-9
Footswitch Type .............................................................................................................................A-9
FOOTSWITCH Connector ......................................................................................................A-9
Footswitch Weld Abort Feature .....................................................................................................A-10
Footswitch Weld Abort On ......................................................................................................A-10
Footswitch Weld Abort Off .....................................................................................................A-10
Firing Switch Type ........................................................................................................................A-10
Firing Circuit ............................................................................................................................A-10
Switch Debounce Time ............................................................................................................A-11
Mechanical Firing Switch Cable ..............................................................................................A-11

MODEL 250DP DUAL PULSE
RESISTANCE WELDING POWER SUPPLY
vi 990-280
Optical Firing Switch Connector .............................................................................................A-11
Initiation Switch .............................................................................................................................A-12
Manual Head Operation ...........................................................................................................A-12
Air Head Operation ..................................................................................................................A-12
Chain Schedules Feature ................................................................................................................A-12
Step Count ................................................................................................................................A-12
Next Schedule ..........................................................................................................................A-13
Audible Buzzer ..............................................................................................................................A-13
End of Cycle Buzzer ON/OFF .................................................................................................A-13
Key Click .................................................................................................................................A-13
Weld Counter .................................................................................................................................A-14
Alarms ......................................................................................................................................A-14
Air Valve Driver ............................................................................................................................A-14
Air Valve Driver 1 ...................................................................................................................A-14
Air Valve Driver 2 ...................................................................................................................A-15
Air Valve Driver Receptacles ..................................................................................................A-15
Control Signals Connector .............................................................................................................A-15
Emergency Stop .......................................................................................................................A-16
Charge (Process) Inhibit ..........................................................................................................A-17
Remote Weld Schedule Selection ............................................................................................A-17
Binary Schedule Selection Code ..............................................................................................A-18
Relay Outputs .................................................................................................................................A-19
Accessory Port ...............................................................................................................................A-20
Input/Output Cable Connectors and Fusing ...................................................................................A-20
Input Line Power ......................................................................................................................A-20
Circuit Breakers .......................................................................................................................A-20
Fuses ......................................................................................................................................A-20
Power Input Connector ............................................................................................................A-20
Front Panel Switches ......................................................................................................................A-21
Microprocessor CPU ......................................................................................................................A-21
Display .......................................................................................................................................A-21
Cooling .......................................................................................................................................A-21
Physical Characteristics .................................................................................................................A-22
Index ................................................................................................................................................ Index-1

MODEL 250DP DUAL PULSE
RESISTANCE WELDING POWER SUPPLY
990-280 vii
ILLUSTRATIONS
Figure Title Page
1-1 250DP Dual Pulse Resistance Welding Power Supply ............................................................... 1-1
2-1 Cable Routing Examples .......................................................................................... 2-2
2-2 Terminal Connection Examples .......................................................................................... 2-2
2-3 Rear Panel Components .......................................................................................... 2-3
2-4 Typical Solenoid Air Valve Assembly with a Single egulator ................................................... 2-6
2-5 250DP Equipment Interconnection Diagram .............................................................................. 2-9
3-1 Front Panel Controls .......................................................................................... 3-1
3-2 Screen Flow Chart .......................................................................................... 3-5
4-1 Typical Solenoid Air Valve System with Dual Regulators ........................................................ 4-2
4-2 Typical Solenoid Air Valve System with a Single Regulator ..................................................... 4-3
4-3 Measuring Preset Firing Force of the Weld Head with a Force Gauge ...................................... 4-4
4-4 Results of Excessive Air Pressure ..........................................................................................4-5
4-5 Weld Head Configuration Jumper Selection .............................................................................. 4-6
5-1 Effects of Excessive or Insufficient Heat, Time and Pressure .................................................... 5-2
5-2 Typical Weld Strength Profile .......................................................................................... 5-7
7-1 Line Voltage and Capacitor Bank Jumpering ............................................................................. 7-2
7-2 100 VAC Line Voltage Configuration ........................................................................................ 7-4
7-3 115 VAC Line Voltage Configuration ........................................................................................ 7-5
7-4 208 VAC Line Voltage Configuration ........................................................................................ 7-6
7-5 230 VAC Line Voltage Configuration ........................................................................................ 7-7
A-1 Rep/Hit Rate with 1500 μF Capacitor Bank .............................................................................. A-5
A-2 Rep/Hit Rate with 3000 μF Capacitor Bank .............................................................................. A-5
A-3 Pin Numbers as Viewed from the Rear Panel .......................................................................... A-11
A-4 Jumper Selection for Air Valve Driver Control ....................................................................... A-15
A-5 CONTROL SIGNALS Connector ....................................................................................... A-16
A-6 Remote Schedule Selection with a Remote Binary Switch ..................................................... A-18
A-7 250DP Dimensions ....................................................................................... A-22

MODEL 250DP DUAL PULSE
RESISTANCE WELDING POWER SUPPLY
viii 990-280
TABLES
Table Title Page
5-1 Recommended Electrode Materials .......................................................................................... 5-3
5-2 Causes of Imperfect Welds .......................................................................................... 5-5
7-1 Power Supply Voltage Range Specifications ............................................................................. 7-9
A-1 Pulse Characteristics ......................................................................................... A-2
A-2 Welding Speed ......................................................................................... A-4
A-3 Binary Codes for Remote Weld Schedule Selection ............................................................... A-17
A-4 Input Power Specifications ....................................................................................... A-21

MODEL 250DP DUAL PULSE
RESISTANCE WELDING POWER SUPPLY
990-280 ix
CONTACT US
Thank you for purchasing a Miyachi Unitek™ Model 250DP Dual Pulse Resistance Welding Power
Supply.
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 Miyachi Unitek Corporation at:
1820 South Myrtle Avenue
P.O. Box 5033
Monrovia, CA 91017-7133
Telephone: [phone]
FAX: [phone]
e-mail: [email protected]
The purpose of this manual is to supply operating and maintenance personnel with the information
needed to properly and safely operate and maintain the Model 250DP Dual Pulse Resistance Welding
Power Supply.
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.
Miyachi Unitek Corporation is not responsible for any loss due to improper use of this product.

MODEL 250DP DUAL PULSE
RESISTANCE WELDING POWER SUPPLY
x990-280
SAFETY NOTES
This instruction manual describes how to operate, maintain and service the Model 250DP Dual Pulse
Resistance Welding Power Supply, and provides instructions relating to its SAFE use. Procedures
described in this manual MUST be performed, as detailed, by QUALIFIED and TRAINED personnel.
For SAFETY, and to effectively take advantage of the full capabilities of the tester, please read these
instruction manuals 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 tester.
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.