Lincoln Electric POWER MIG 255 Service Manual Download Page 103

G-7

ELECTRICAL DIAGRAMS

POWER MIG 255

CONTROL PC BOARD ASSEMBLY - (G3521-1)

Ch’ge. Sht. No.

3521-1    

XE-RW          

            

            
            

            

         A   

            

            

            
            

            

            

            

            

            
            

            

            

            

            

            
            

            

            

            

            

            
            

           POWER MIG 255          

    CONTROL P.C. BOARD ASSEMBLY   

C.S./     

    FULL    

3521-1    

            

       

12-18-98

   G2803-1  

THE LINCOLN ELECTRIC CO.

CLEVELAND, OHIO U.S.A.

EQUIP.

TYPE

SCALE

DR

DATE

CHK

REF.

SUBJECT

SUP’S’D’G

SHT.

NO.

G

G

5.80

.20

3-12-99    

7-9-99H    

7-28-2000J    

10-5-2001C    

6.00

~.04

0

0

.20

3.20

8.80

9.00

~.04

 

 ITEM

REQ’D

 PART NO.

IDENTIFICATION

XXXXXXXXXXXXXXXX

XXXXXXXXXXXXXXX

XXXXXXXXXXXXXX

XXXXXXXXXXXXX

XXX

 X1  

 J1  

 J2  

 J3  

 J5  

 J6  

 J8  

R74  

R71  

C24  

C25  

R72  

R73  

R83  

D26  

C29  

D27  

R75  

R70  

D21  

D22  

C22  

X3   

R69  

R68  

C23  

R77  

R76  

R78  

C46  

R98  

D33  

D35  

R101 

 L2  

 L1  

R8   

D3   

D1   

C1   

R6   

C2   

R4   

R5   

R42  

D31  

D2   

C44  

R1   

R2   

R87  

R92  

C31  

R91  

R86  

C30  

R10  

R11  

R9   

D4   

D6   

R12  

D7   

D5   

  Q7  

 C50

  Q10 

 R54 

 C27 

  X12 

 C28 

DZ1  

D15  

R55  

R56  

 C16 

DZ2  

R52  

R51  

  X10 

  X11 

D14  

R49  

R50  

R48  

R53  

  Q5  

 Q4  

D25  

R81  

R82  

TP4  

TP3  

 C35

 C19

 C18

DZ3  

R105 

X8   

C7   

C48  

D13  

R33  

D12  

R34  

R40  

DZ4  

R107 

D36  

  Q8  

  Q6  

R106 

  Q9  

  Q3  

R104 

R32  

X5   

R28  

R29  

C8   

R39  

X9   

C49  

R36  

R102 

R103 

R57  

 C15 

 C17 

R47  

R37  

X4   

R38  

R35  

C9   

 TP1 

 TP2 

 C5 

 C6 

D10  

D8   

R27  

R15  

D9   

C3   

R14  

R23  

D11  

C4   

R94  

R93  

  Q1  

  Q2  

R24  

R80  

R20  

R18  

R60  

R65  

C32  

C34  

C33  

D16  

D29  

X6   

R61  

D17  

D18  

R63  

 L3  

 L4  

R67  

R64  

C20  

R58  

D20  

D19  

R62  

R13  

R22  

C41  

C36  

C37  

C40  

C38  

C39  

  X7  

D28  

R41  

D23  

D24  

R79  

R99  

D34  

R100 

R95  

C43  

R90  

R84  

R43  

R45  

R44  

  X2  

C10  

C14  

 C54

 TP7 

 C51

 TRI1 

C52  

R109 

R108 

C53  

  Q11 

R111 

R110 

C11  

R46  

C45  

R97  

R96  

D30  

D32  

R31  

R30  

R19  

R21  

CONTROL

G3521-1

R112 

R113 

C55  

C56  

C57  

C12  

C13  

C47  

 OCI1 

 OCI2 

 R7  

 R3  

 Y1  

C58  

R116 

R115 

 R25 

R114 

 C26 

 R26 

R117 

 J4  

D37  

R66  

R59  

R88  

R89  

 OCI3 

C1,C2,C8,C9,C14,C20,C29
C36,C37,C38,C39,C43,C44 
C48,C52,C53,C55,C56
C3,C4,C11
C5,C6,C18,C19,C35,C51,C54
C7
C10,C22,C23,C24,C25,C30
C31,C32,C33,C34,C40,C41 
C45,C46,C57,C58
C12,C13
C15
C16
C17,C28
C26
C27
C47
C49
C50
C59
D1,D2,D3,D31
D4,D5,D6,D7,D8,D9,D10,D11,D12,D13,D14,
D15,D16,D17,D18,D19,D20,D21,D22,D24  
D25,D26,D27,D28,D29,D30 
D32,D33,D34,D35,D36
D23,D37
DZ1
DZ2,DZ3,DZ4
J1
J2
J3
J4
J5
J6
J8
L1,L2,L3,L4
OCI1,OCI2
OCI3
Q1,Q2,Q3,Q6,Q11
Q4
Q5,Q9
Q7,Q10
Q8
R1,R2,R6,R41,R42,R65,R75
R79,R84,R112,R113
R3,R7,R25,R26,R114,R117
R4,R51
R5,R9,R12,R30,R35,R45,R70
R90
R8,R115
R10,R11,R62,R63,R76,R77
R78,R82,R95,R105
R13,R22,R93,R94
R14,R15,R23,R27
R18,R20,R24,R80
R19,R21,R58,R83
R28,R46,R61
R29,R100,R110
R31,R106
R32
R33,R37,R38
R34,R40
R36
R39,R68,R71,R72,R91,R92
R111
R43
R44,R109
R47
R48
R49,R50
R52,R98
R53
R54
R55,R56
R57,R108
R59,R66,R69,R73,R74,R86,R87
R60
R64,R67
R81
R88,R89
R96,R103
R97
R99
R101,R102
R104
R107
R116
TP1,TP2
TP3,TP4
TP7
TRI1
X1
X2
X3
X4,X5
X6
X7
X8
X9
X10,X11
X12
Y1

18
 
 
3
7
1
16
 
 
2
1
1
2
1
1
1
1
1
1
4
31
 
 
  
2
1
3
1
1
1
1
1
1
1
4
2
1
5
1
2
2
1
11
 
6
2
8
 
2
10
 
4
4
4
4
3
3
2
1
3
2
1
7
 
1
2
1
1
2
2
1
1
2
2
7
1
2
1
2
2
1
1
2
1
1
1
2
2
1
1
1
1
1
2
1
1
1
1
2
1
1

1.0/35

20/50

22pF/100
39/10
3300/50
18/15

2200/63V
820pF/50

0.27/63V
1N4007
1N4004  

1N5818
1N4735
1N4746A
HEADER
HEADER
HEADER
HEADER,VERTICAL
HEADER
HEADER
HEADER
330uH

OPTOCOUPLER,TRIACDRV,RANDOM,800V
2N4401
HEATSINK ASBLY
NPN TRANSISTOR
TRANSISTOR,NMF,T220,45A,100V(SS)
2N4403

120 2.5W
15K 1/4W
4.75K   
4.75K    7/16W
1.21K 1/4W

1.21K 1/4W
681 1/4W

562 1/4W
2.21K 1/4W
6.81K 1/4W

5.62K 1/4W
26.7K 1/4W
22.1K 1/4W

2.67K 1/4W

3.01K 1/4W

5.11K 1/4W

267 1/4W

24.3K 1/4W
511 1/4W

16.2K 1/4W
47.5K 1/4W

16.5K 1/4W
13.7K 1/4W
750 1/4W
475 1/4W
28.0K 1/4W
15J
20J
MOV,120J
T2500D

IC,S8054HN,CMOS,UNDERVOT-SENSING(SS)
14 PINI.C.(SS)

IC,SWITCH,LO-SIDE(SS)
MC14584(SS)

+5V REG.

.022/50

.1/50

.0047 OR .005/1400

ROM ASSEMBLY (SS)

S16668-5
 
 
S13490-42
T11577-52
S13490-73
S16668-11
 
 
S16668-1
S13490-30
S13490-92
S13490-39
T11577-28
S13490-118
S16668-7
S13490-76
S13490-102
S24833-1
T12199-2
T12199-1
 
  
 
T12705-23
T12702-40
T12702-45
S18248-8
S18248-14
S18248-12
S24020-10
S18248-16
S18248-6
S18248-2T
T12218-7
S15000-30
S15000-31
T12704-68
S18105-4
T12704-35
T12704-88
T12704-69
S19400-1002
 
S24002-1200
S19400-1502
S19400-4751
 
S19400-1211
S19400-1000
 
S19400-6810
S19400-15R0
S19400-5620
S19400-2211
S19400-6811
S19400-1501
S19400-5621
S19400-2672
S19400-2212
S19400-33R2
S19400-2671
S19400-3321
 
S19400-1004
S19400-1001
S19400-1301
S19400-2801
T14648-22
S19400-3011
S19400-5111
T12300-75
S19400-26R7
S19400-2670
S19400-4422
S19400-2432
S19400-5110
T14648-5
S19400-1622
S19400-4752
T14648-19
S19400-1652
S19400-1372
S19400-7500
S19400-4750
S19400-2802
T13640-15
T13640-9
T13640-18
S15161-27
S24392-4
M15102-3
S17900-8
S15128-11
S15128-16
S23060-1
S15018-4
S15018-6
S15128-10
S15128-5
S16665-5

.25 OHM, 7W RESISTOR

.047/100

.001/400

.22/100

OPTOCOUPLER TRIAC DRIVER 800V

10K 1/4W 

100 1/4W 

15 1/4W

1.5K 1/4W

33.2 1/4W

3.32K 1/4W       

1M 1/4W
1K 1/4W
1.3K 1/4W
2.8K 1/4W
50 5W

26.7 1/4W

44.2K 1/4W       

3.3K 5W

1K 5W

14 PIN QUAD COMPARATOR
IC,LT1014,LINEAR INTEGRATED CIRCUIT

DIGITAL INTEGRATED CIRCUIT(SS)
IC,431,VOLTAGE REF.

8.0 MHZ

11-16-2001D    

G-7

Retur

n to Section TOC

Retur

n to Section TOC

Retur

n to Section TOC

Retur

n to Section TOC

Retur

n to Master TOC

Retur

n to Master TOC

Retur

n to Master TOC

Retur

n to Master TOC

NOTE:

Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available
from Lincoln Electric. 
This information is provided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the
Machine Operator or Technician. Improper PC board repairs could result in damage to the machine.

Summary of Contents for POWER MIG 255

Page 1: ...TAINED THROUGHOUT And most importantly think before you act and be careful SERVICE MANUAL For use with machines having Code Number 10563 10583 10986 10990 Return to Master TOC Return to Master TOC Ret...

Page 2: ...S INJURY OR DEATH KEEP CHILDREN AWAY PACEMAKER WEARERS SHOULD CONSULT WITH THEIR DOCTOR BEFORE OPERATING Read and understand the following safety highlights For additional safety information it is str...

Page 3: ...work or metal to be welded to a good electrical earth ground 3 f Maintain the electrode holder work clamp welding cable and welding machine in good safe operating condition Replace damaged insulation...

Page 4: ...ng area If this is not possible cover them to prevent the welding sparks from starting a fire Remember that welding sparks and hot materials from welding can easily go through small cracks and opening...

Page 5: ...travaillant proximit au soudage l aide d crans appropri s et non inflammables 4 Des gouttes de laitier en fusion sont mises de l arc de soudage Se prot ger avec des v tements de protection libres de l...

Page 6: ...TS FOR ALL SECTIONS Safety i iv Installation Section A Operation Section B Accessories Section C Maintenance Section D Theory of Operation Section E Troubleshooting and Repair Section F Electrical Dia...

Page 7: ...ction A 1 TABLE OF CONTENTS INSTALLATION SECTION Installation Section A Technical Specifications A 2 Safety Precautions A 3 Uncrating the POWER MIG 255 A 3 Location A 3 Input Power Grounding and Conne...

Page 8: ...0 25 19 14 2 5 mm2 12 4 mm2 NOTE Use 10 AWG Grounding Wire TECHNICAL SPECIFICATIONS POWER MIG 255 INPUT SINGLE PHASE ONLY RATED OUTPUT OUTPUT RECOMMENDED INPUT WIRE AND FUSE SIZES Height Width Depth W...

Page 9: ...ire installation section before starting installation SAFETY PRECAUTIONS ELECTRIC SHOCK can kill Only qualified personnel should perform this installation Only personnel that have read and under stood...

Page 10: ...n the following dia gram The center contact in the receptacle is for the grounding connection A green wire in the input cable connects this contact to the frame of the welder This ensures proper groun...

Page 11: ...SINGLE PHASE SYSTEM OR TO ONE PHASE OF A TWO OR THREE PHASE SYSTEM OUTPUT POLARITY CONNECTIONS The welder as shipped from the factory is connected for electrode positive polarity This is the normal po...

Page 12: ...rt dust oil or grease Remove dust and dirt with a clean cloth DO NOT ATTACH THE REGULATOR IF OIL GREASE OR DAMAGE IS PRESENT Inform your gas supplier of this condition Oil or grease in the presence of...

Page 13: ...30 lb 14 kg Readi Reel Package Using the Molded Plastic K363 P Readi Reel Adapter B 5 To Mount 10 to 44 lb 4 5 20 kg Spools 12 in 300 mm Diameter or 14 lb 6 kg Innershield Coils B 5 To Start the Weld...

Page 14: ...touch electrically live parts or electrode with skin or wet clothing Insulate yourself from work and ground Always wear dry insulating gloves FUMES AND GASES can be dangerous Keep your head out of fu...

Page 15: ...ctable 4 step trigger inter lock and adjustable Run In for wire starting optimiza tion Also optional are a Spool Gun Adapter kit a Dual Cylinder Mounting Kit and an Aluminum Feeding Kit for push feedi...

Page 16: ...eed is not affected when changes are made in the voltage control WIRE DRIVE ROLL The drive rolls installed with the POWER MIG each have two grooves both for 0 030 0 0035 in 0 8 0 9 mm solid steel elec...

Page 17: ...ollar retainers fully engage the retaining ring groove on the spindle 5 Rotate the spindle and adapter so the retaining spring is at the 12 o clock position 6 Position the Readi Reel so that it will r...

Page 18: ...ire wire diameter surface conditions lubrication and hardness As a general rule hard wires may require greater pressure and soft or aluminum wire may require less pressure than the factory setting The...

Page 19: ...wire at low speed regardless of the set wire feed speed until the welding arc starts or 1 second has elapsed This feature enhances starting and makes it easier to set the stickout The 1 second limit...

Page 20: ...input The unit will continue to weld but the output may be less than what is set WIRE FEED OVERLOAD PROTECTION The POWER MIG has solid state overload protection of the wire drive motor If the motor b...

Page 21: ...2 mm Aluminum Feeding Kit K1703 1 C 2 K363P Readi Reel Adapter C 2 Dual Cylinder Mounting Kit K1702 1 C 2 Alternative Magnum GMAW Gun and Cable Assemblies C 2 Magnum Gun Connection Kit Optional K466 6...

Page 22: ...M GMAW GUN AND CABLE ASSEMBLIES The following Magnum 250L gun and cable assemblies are separately available for use with the POWER MIG 255 Each is rated 200 amps 60 duty cycle or 250 amps 40 duty and...

Page 23: ...ure the machine will reset to the trigger off condition automatically 3 Spot Weld Mode is used for tack welding parts into position or for spot plug welds to hold thin sheet metal together prior to ma...

Page 24: ...ure unused gun is positioned so electrode or tip will not contact metal case or other metal common to work 1 Pulling the trigger for the built in feeder gun a Disables spool gun operation b Closing fe...

Page 25: ...autions D 2 Routine and Periodic Maintenance D 2 Drive Rolls and Guide Tubes D 2 Cable Cleaning D 2 Gun Tubes and Nozzles D 2 Contact Tip and Gas Nozzle Installation D 4 Liner Removal and Replacement...

Page 26: ...parts Refer to Figure D 1 Main transformer and output choke Power enhancement choke Wire drive assembly Capacitor bank SCR rectifier bridge and heat sink fins Fan motor assembly Control printed circui...

Page 27: ...Return to Section TOC Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC FIGURE D 1 COMPONENT LOCATIONS CONTROL PC BOARD POWER ENHANCEMENT CHOKE OUTPUT CHOKE MAIN TRAN...

Page 28: ...MMING INSTRUCTIONS FOR MAGNUM 250L NOTE The variation in cable lengths prevents the interchangeability of liners between guns Once a liner has been cut for a particular gun it should not be installed...

Page 29: ...o turn the collar past an internal locking rib See Figure D 3 FIGURE D 3 GUN HANDLE DISASSEMBLY 9 Tighten the setscrew on the brass cable connector NOTE Do not install the gas diffuser onto the end of...

Page 30: ...025 in 0 030 in 0 035 in 0 045 in 0 035 in 0 045 in 0 025 in 0 030 in 0 035 in 0 045 in 3 64 in Alum wire 3 8 in 1 2 in 5 8 in 3 8 in 5 8 in 5 8 in 0 025 0 045 in 1 2 in 5 8 in 0 25 0 030 in 0 35 0 0...

Page 31: ...rload Protection E 6 Overcurrent Protection E 6 Wire Feed Overload Protection E 6 SCR Operation E 7 TABLE OF CONTENTS THEORY OF OPERATION SECTION FIGURE E 1 BLOCK LOGIC DIAGRAM LINE SWITCH RECONNECT M...

Page 32: ...E AND MAIN TRANSFORMER LINE SWITCH RECONNECT MAIN TRANSFORMER SNUBBER BOARD RECTIFIER DIODE BRIDGE ARC VOLTAGE WIRE SPEED GAS SOLENOID FAN MOTOR CONTROL BOARD WIRE DRIVE MOTOR TACH GUN TRIGGER FEEDBAC...

Page 33: ...on LINE SWITCH RECONNECT MAIN TRANSFORMER SNUBBER BOARD RECTIFIER DIODE BRIDGE ARC VOLTAGE WIRE SPEED GAS SOLENOID FAN MOTOR CONTROL BOARD WIRE DRIVE MOTOR TACH GUN TRIGGER FEEDBACK 115 VAC 30 VAC G A...

Page 34: ...discussion FIGURE E 4 CONSTANT VOLTAGE OUTPUT LINE SWITCH RECONNECT MAIN TRANSFORMER SNUBBER BOARD RECTIFIER DIODE BRIDGE ARC VOLTAGE WIRE SPEED GAS SOLENOID FAN MOTOR CONTROL BOARD WIRE DRIVE MOTOR...

Page 35: ...ion FIGURE E 5 WIRE DRIVE MOTOR AND FEEDBACK LINE SWITCH RECONNECT MAIN TRANSFORMER SNUBBER BOARD RECTIFIER DIODE BRIDGE ARC VOLTAGE WIRE SPEED GAS SOLENOID FAN MOTOR CONTROL BOARD WIRE DRIVE MOTOR TA...

Page 36: ...ch may be left on and the reset should occur within a 15 minute period If the fan is not turning or the air intake louvers are obstructed then the input power must be removed and the fan problem or ai...

Page 37: ...SCR the device spends a certain portion of the AC cycle time in the off state and the remainder of the time in the on state The amount of time spent in the ON state is con trolled by the gate An SCR...

Page 38: ...POWER MIG 255 NOTES E 8 E 8 Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOC Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC...

Page 39: ...otor and Tachometer Feedback Test F 27 Oscilloscope Waveforms Normal Open Circuit Voltage Waveform F 31 Typical Output Voltage Waveform Machine Loaded F 32 Abnormal Output Voltage Waveform Machine Loa...

Page 40: ...SADJUSTMENT S lists the obvious external possibilities that may contribute to the machine symptom Perform these tests checks in the order listed In general these tests can be conducted without removin...

Page 41: ...uipment Do not touch electrically hot parts Remove the PC board from the static shielding bag and place it directly into the equipment Don t set the PC board on or near paper plastic or cloth which co...

Page 42: ...Service Facility 1 Make certain that the input power switch is in the ON posi tion 2 Check the input voltage at the machine Input voltage must match the rating plate and the reconnect panel 3 Blown or...

Page 43: ...the machine Input voltage must match the rating plate and the reconnect panel 2 The gun may be faulty Check or replace 1 Make sure that the proper wire and procedures are being used 2 Check gun and w...

Page 44: ...MPTOMS POSSIBLE AREAS OF MISADJUSTMENT S RECOMMENDED COURSE OF ACTION The output voltage and wire feed is present continuously or pulsing when gun trigger is NOT activated The output voltage is presen...

Page 45: ...resolved 1 Check gas source and hoses for leaks or kinks 1 Check for adequate wire supply 2 Check for mechanical restric tions in the wire feeding path The gun may be clogged 3 Check gun liner and ti...

Page 46: ...is no wire feed when gun trig ger is pulled Normal open circuit voltage is present 1 The wire feed speed control may be dirty Rotate several times and check if problem is resolved 1 Check for adequate...

Page 47: ...dirty wire 5 Make sure machine settings and gas are correct for process being used 1 Make sure the weld procedure and electrode polarity is correct for the process being used 2 Make sure shielding gas...

Page 48: ...ue to excessive current and or high duty cycle welding 2 A light application of high tem perature anti sieze lubricant such as Lincoln E2607 Graphite Grease may be applied to the contact tip threads 1...

Page 49: ...rs safely contact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed Call 1 888 935 3877 POWER MIG 255 F 11 F 11 Return to Section TOC Return to Secti...

Page 50: ...ads on plug J6 on the G3521 control PC board TEST PROCEDURE The ON OFF POWER SWITCH will be hot during these tests NOTE Secondary voltages will vary pro portionately with the primary input voltage 1 D...

Page 51: ...s and the main transformer d If the voltage is not corrected go to step 16 13 Turn OFF the machine power 6 Connect main input power to the machine 7 Turn the POWER MIG 255 ON OFF POWER SWITCH to ON 8...

Page 52: ...panel and the ON OFF POWER SWITCH test the ON OFF POWER SWITCH for proper operation b If the correct nameplate voltage is being applied to the main trans former and one or more of the sec ondary volt...

Page 53: ...actory war ranty For your safety and to avoid electrical shock please observe all safety notes and precautions detailed throughout this manual If for any reason you do not understand the test procedur...

Page 54: ...206 is connected at the output shunt See the wiring diagram 5 Connect main input power to the machine TEST PROCEDURE 1 Disconnect the main AC input power to the machine 2 Remove the case top and side...

Page 55: ...or missing and the AC voltages are cor rect the rectifier diode bridge may be faulty 6 Turn the POWER MIG 255 ON OFF POWER SWITCH to ON 7 Carefully make the following voltage tests a Turn the machine...

Page 56: ...OWER MIG 255 NOTES F 18 F 18 Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOC Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC...

Page 57: ...o avoid electrical shock please observe all safety notes and precautions detailed throughout this manual If for any reason you do not understand the test procedures or are unable to per form the test...

Page 58: ...ohmmeter 5 Disconnect plugs J6 from the G3521 control board and J9 from the M19248 snubber PC board This electrically isolates the SCR bridge assembly See Figure F 3 TEST PROCEDURE 1 Disconnect main...

Page 59: ...and 7 to test SCR 2 11 Reconnect leads X2 and X3 braided copper strap 12 Reconnect plugs J9 and J6 13 If this test did not identify the problem or to further test the SCR go to the Active SCR Rectifie...

Page 60: ...OWER MIG 255 NOTES F 22 F 22 Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOC Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC...

Page 61: ...tes and precautions detailed throughout this manual If for any reason you do not understand the test procedures or are unable to per form the test repairs safely contact the Lincoln Electric service d...

Page 62: ...lt ohmmeter 5 Disconnect plugs J6 from the G3521 control board and J9 from the M19248 snubber PC board This electrically isolates the SCR bridge assembly See Figure F 6 TEST PROCEDURE 1 Disconnect mai...

Page 63: ...he voltage level of the battery Short leads A and C Close switch SW 1 Battery voltage should be 4 5 volts or higher If lower replace the battery FIGURE F 8 SCR TESTER CIRCUIT AND SCR CONNECTIONS 6 Dis...

Page 64: ...ds X2 and X3 to the neg ative capacitor bank bus bar 22 Replace the tool tray and case sides 9 Connect the tester to the SCR 1 as shown in Figure F 8 a Connect tester lead A to the anode b Connect tes...

Page 65: ...r to the technician or machine operator and will invalidate your factory war ranty For your safety and to avoid electrical shock please observe all safety notes and precautions detailed throughout thi...

Page 66: ...llowing leads on plug J1 5 Connect the main power to the machine TEST PROCEDURE NOTE POLARITY MUST BE OBSERVED FOR THESE TESTS Test for Correct Wire Drive Motor Armature Voltage 1 Disconnect main inpu...

Page 67: ...d 6 Make the following voltage tests a Turn the machine OFF between each test b Carefully insert the meter probes into the back of each Molex plug pin cavity to perform the test c Turn the machine ON...

Page 68: ...ck the leads from the tachometer circuit to the control PC board for loose or broken connections 8 If the leads are okay the tachometer circuit may be faulty replace the tachometer circuit 9 Replace t...

Page 69: ...5 ms This is a typical DC output voltage waveform generated from a properly operating machine Note that each vertical division represents 20 volts and that each horizontal division represents 2 5 mil...

Page 70: ...AL OUTPUT VOLTAGE WAVEFORM MACHINE LOADED This is a typical DC output voltage waveform generated from a properly operating machine Note that each vertical division represents 20 volts and that each ho...

Page 71: ...UNCTIONING This is NOT a typical DC output voltage waveform One output SCR is not function ing Note the increased ripple content One SCR gate was disconnected to simulate an open or non functioning ou...

Page 72: ...K NOT FUNCTIONING This is NOT the typical DC output voltage waveform The output capacitors are not functioning Note the lack of filtering in the output waveform The output capacitor bank was disconnec...

Page 73: ...VOLTAGE WAVEFORM This is a typical SCR gate pulse voltage waveform The machine was in an open circuit condition no load and operating properly Note that each vertical division represents 2 volts and...

Page 74: ...OWER MIG 255 NOTES F 36 F 36 Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOC Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC...

Page 75: ...all safety notes and pre cautions detailed throughout this manual If for any reason you do not understand the test procedures or are unable to per form the test repairs safely contact the Lincoln Ele...

Page 76: ...HOOTING AND REPAIR CONTROL PC BOARD REMOVAL AND REPLACEMENT PROCEDURE Continued REMOVAL AND REPLACEMENT PROCEDURE 1 Disconnect main input power the machine 2 Open the side panels and remove the tool t...

Page 77: ...oard carefully secure board to mounting standoffs 8 Install all plug connectors previously removed from the control PC board 9 Install the tool tray and close the side panels 4 Ensure a static electri...

Page 78: ...OWER MIG 255 NOTES F 40 F 40 Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOC Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC...

Page 79: ...our safety and to avoid electrical shock please observe all safety notes and pre cautions detailed throughout this manual If for any reason you do not understand the test procedures or are unable to p...

Page 80: ...to the machine 2 Remove the wire gun and wire 3 Lift the wire drive door to gain access to the wire drive assembly 4 Lift the tool tray door to allow access to the tool tray 5 Use a 5 16 in nutdriver...

Page 81: ...e wire drive assembly from the wire drive compartment 18 Reassemble the wire drive assembly in the reverse order 10 Rotate the adjustment arm assembly counterclockwise to release the tension on the id...

Page 82: ...OWER MIG 255 NOTES F 44 F 44 Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOC Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC...

Page 83: ...or your safety and to avoid electrical shock please observe all safety notes and pre cautions detailed throughout this manual If for any reason you do not understand the test procedures or are unable...

Page 84: ...ga tive capacitor band buss bar on the right side of the machine using a 1 2 in socket and 3 8 in open end wrench FIGURE F 14 MIDDLE HEAT SINK LEAD DISCONNECTION PROCEDURE 1 Remove the case side panel...

Page 85: ...s 320 and 320B from the SCR heat sink thermostat on the right side at the SCR assembly 10 Reassemble the SCR assembly in the reverse order 5 Remove lead 209S and transformer lead X4 from the right sid...

Page 86: ...OWER MIG 255 NOTES F 48 F 48 Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOC Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC...

Page 87: ...ian or machine operator and will invalidate your factory warranty For your safety and to avoid electrical shock please observe all safety notes and pre cautions detailed throughout this manual If for...

Page 88: ...remove the capacitor bank assembly from the machine 10 Reassemble the capacitor bank in the reverse order PROCEDURE See Figure F 16 for location of capacitor bank removal and replacement components 1...

Page 89: ...l shock please observe all safety notes and pre cautions detailed throughout this manual If for any reason you do not understand the test procedures or are unable to per form the test repairs safely c...

Page 90: ...thermostat leads 320 and 320B from the SCR Rectifier PROCEDURE 1 Disconnect main input power to the machine 2 Remove the case side panels using a 3 8 in nutdriver 3 Test that the capacitors are disch...

Page 91: ...r bank buss using two 1 2 in open end wrenches 13 Remove the other output choke lead from the positive output terminal using a 1 2 in wrench 13 Remove all cable ties wire mounts and any har ness type...

Page 92: ...OWER MIG 255 NOTES F 54 F 54 Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOC Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC...

Page 93: ...your factory warranty For your safety and to avoid electrical shock please observe all safety notes and pre cautions detailed throughout this manual If for any reason you do not understand the test pr...

Page 94: ...he fan blade clamp Ensure the fan is in the same position on the shaft as it was prior to removal a Spin the fan to be sure it is free to rotate 7 Reassemble the remaining compo nents in reverse order...

Page 95: ...tion TOC Return to Section TOC Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC INPUT IDLE AMPS AND WATTS WIRE SPEED RANGE OPEN CIRCUIT VOLTAGE RETEST AFTER REPAIR M...

Page 96: ...OWER MIG 255 NOTES F 58 F 58 Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOC Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC...

Page 97: ...Machine Code 10563 L10979 G 2 Wiring Diagram Entire Machine Code 10583 L10980 G 3 Wiring Diagram Entire Machine Code 10986 L11980 G 4 Wiring Diagram Entire Machine Code 10990 L11979 G 5 Control PC Boa...

Page 98: ...3 2 3 4 5 CONTROL BOARD CONDUCTOR STRAP AND WORK STUD OFF AND REVERSE LEAD CONNECTIONS AT CABLE POSITIVE TO CHANGE POLARITY TURN THE UNIT FUTURE APPLICATIONS 8 7 6 5 4 3 B W 555 354 D2 BAFFLE MOUNTED...

Page 99: ...G2 325 J11 1 1 2 3 X8 3 4 C3 C2 C1 X2 X3 R4 INDICATES CONNECTOR CAVITY NO U BLUE R RED W WHITE B BLACK SECONDARY VOLTAGES SHOWN ARE NO LOAD RMS VALUES OUTPUT CHOKE THERMOSTAT B 206S L1 H2 H5 5 R H4 H1...

Page 100: ...ARC VOLTAGE DISPLAY BOARD 253 R4 500 515 550 551 552 209R 208R 354 J11 1 2 3 4 325 324 325 4 2 GUN TRIGGER 324 5 2 3 2 4 1 2 3 2 5 5 2 3 4 7 11 6 3 8 9 2 5 4 J8 252 550 254 500 J4 4 7 6 14 11 1 J5 J6...

Page 101: ...3 2 1 ARC VOLTAGE DISPLAY BOARD 253 R4 500 515 550 551 552 209R 208R 354 J11 1 2 3 4 325 324 325 4 2 GUN TRIGGER 324 5 2 3 2 4 1 2 3 2 5 5 2 3 4 7 11 6 3 8 9 2 5 4 J8 252 550 254 500 J4 4 7 6 14 11 1...

Page 102: ...ity for liablilities resulting from board level troubleshooting PC Board repairs will invalidate your factory warranty Individual Printed Circuit Board Components are not available from Lincoln Electr...

Page 103: ...2 2 1 1 2 2 7 1 2 1 2 2 1 1 2 1 1 1 2 2 1 1 1 1 1 2 1 1 1 1 2 1 1 1 0 35 20 50 22pF 100 39 10 3300 50 18 15 2200 63V 820pF 50 0 27 63V 1N4007 1N4004 1N5818 1N4735 1N4746A HEADER HEADER HEADER HEADER V...

Page 104: ...10 11 475 R8 50V 0047 C7 X5 8 9 10K R6 10K R5 475 R9 DISP7 2 1 4 9 5 10 7 6 8 3 DISP6 2 1 4 9 5 10 7 6 8 3 500 500 500 14 3 Rx Vdd d BANK1 g DATA OUT f ENABLE MC14489 DATA IN h Vss BANK3 BANK4 BANK2 a...

Page 105: ...657 6 RED LED R1 R2 R3 R4 R13 R14 6 S19400 2210 221 1 4W R5 R6 R7 3 S19400 1002 10K 1 4W R8 R9 R10 3 S19400 4750 475 1 4W R11 R12 2 S19400 1501 1 5K 1 4W X1 1 S15128 5 5V REG X3 X4 2 S20496 1 IC MC144...

Page 106: ...UBJECT CLEVELAND OHIO U S A TYPE COMMON CONNECTION UNLESS OTHERWISE SPECIFIED RESISTORS Ohms THIS DIAGRAM MAY NOT A PRINTED SUPPLY 1A 400V 209S 209 208S 208 208R 400V 68 C1 5 12 98 204 XB RW 3 12 99 G...

Page 107: ...M16647 1 2 00 C1 C2 2 T11577 68 0 68 MFD 400 WVDC CAPACITOR J1 1 S18248 8 HEADER R1 R2 2 T14648 25 10 5W 20 3 80 20 1 80 4 00 04 M19248 1 SNUBBER J1 R1 R2 C1 C2 1 12 2001D A NOTE Lincoln Electric ass...

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