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