Troubleshooting & repair, Meter calibration adjustments (continued), F-21 – Lincoln Electric PRECISION TIG 275 SVM162-B User Manual
Page 67: Ammeter calibration procedure, Voltmeter calibration procedure, Figure f.2 - control board trimmers, R-5 r-2, X1 5
F-21
F-21
PRECISION TIG 275
TROUBLESHOOTING & REPAIR
AMMETER CALIBRATION PROCEDURE
1. Locate the Ammeter Calibration Trimmer (R5). See
Figure F.1.
2. Set to TIG mode with DC polarity and LOCAL con-
trol. Without closing the arc start switch, preset the
maximum output panel control so the panel digital
meter reads approx. 200 amps.
3. Using a DC (AVG.) test ammeter with at least 1%
accuracy at up to 300 amps, connect it to measure
the DC current through a short weld cable shorting
out the work(+) to electrode(-) studs on the front stud
panel. Remove the TIG torch if connected.
4. Close the arc start switch just long enough to com-
pare the panel meter reading to that of the test
ammeter. The short circuit current readings should
match within 4% +/-2A. If not, adjust the trimmer so
that the panel meter accuracy is corrected.
VOLTMETER CALIBRATION PROCEDURE
1. Locate the Voltmeter Calibration Trimmer (R2) on
the control board. See
2. To prevent maximum OCV output, disconnect the
SCR gate lead plug from receptacle J4.
3. Set to TIG mode with DC- polarity without closing the
arc start switch.
4. Using a DC (avg.) test voltmeter with at least 1%
accuracy at up to 100 volts, connect it across the
work (+) and electrode (-) studs on the front stud
panel. Remove the TIG torch, if connected.
5. Press the display panel switch to V (volts) position,
then close the arc start switch just long enough to
compare the panel meter reading to that of the test
volt meter. The open circuit voltage readings (about
50 VDC) should match within 3% +/-1v. If not, adjust
the trimmer so that the panel meter accuracy is cor-
rected.
NOTE: If the Arc Start switch is held closed longer than
about 15 seconds, the machine will shut down
to protect internal holding resistor from over-
heating.
METER CALIBRATION ADJUSTMENTS (continued)
X
X
X
X
X
X
X
X
X
X
X
X
X
X
XXX
XXX
X X X X
X X X X
X
X
X
X
X X X X X X
X X
X X X X X X
X X
X X
X X
X X
X X
X X X X
X
X
X
X
X
X
X
X
X
X
X X
D
Z
1
6
C47
R274
D58
R93
D21
X
1
1
D65
C106
C35
Q17
D
8
0
Q23
Q14
C31
R96
C
1
2
8
C
1
5
2
R318
R
3
3
3
C76
R
3
3
1
DZ22
D67
C
1
5
5
R134
X
1
0
R205
C34
C19
C45
C59
C87
R161
X
1
6
R
3
1
9
R102
C14
C
1
2
4
D23
R
2
8
2
C4
Y
1
R
3
8
R
2
0
7
R279
C105
R
1
DZ10
C71
R257
C157
R92
R166
R3
D
Z
1
5
J6
R203
R34
C
1
7
R2
D62
Q9
R106
D22
D19
R175
R246
R168
R165
C
1
4
6
R128
C30
C104
R269
Q16
R107
R10
R121
R176
R126
R95
R247
R
3
2
0
OCI7
R315
R78
C20
R292
R
2
9
5
R65
J8
D6
D
7
3
D31
R
2
9
4
R76
R41
R
3
0
8
D34
R293
R60
J9
D
Z
1
8
R6
R
3
2
3
C
5
7
R
2
4
3
D
9
0
C90
C15
R311
R173
R249
C
1
2
R
1
7
2
R94
D
Z
1
9
R71
R
3
0
7
R
2
6
7
C127
R317
C93
X
7
R252
R162
C
1
4
0
R61
R75
R122
C88
C70
R321
R82
R
3
3
4
R
2
5
6
R
3
2
5
R
3
3
0
C107
R
3
3
7
R314
R335
R
2
8
4
C103
D
7
9
R
3
6
4
R358
R12
C110
C49
D11
J5A
D82
R245
X
4
R210
J7
C
1
5
3
R248
R209
X
1
7
C
1
3
9
R275
R352
C85
D81
J
2
C151
R98
R32
R204
Q27
C64
Q25
R28
R353
R174
D89
D
Z
2
0
R119
R
3
2
2
J10
DZ17
C36
C56
R
1
7
1
OCI6
R255
D2
R167
DZ25
R
3
9
R259
R7
Q18
C18
C150
R100
R69
C109
R125
C108
R120
R
2
6
D
Z
1
2
R251
R
2
5
0
R
3
5
6
C3
R
2
8
5
D
7
2
R
2
8
1
C158
R64
R
3
3
2
R36
Q19
C165
C
1
4
8
D63
R163
C
1
2
2
R
3
0
9
R
2
9
0
R336
R357
R270
C
1
2
1
R253
R72
DZ9
C119
R276
C
1
4
5
R361
R
2
8
9
D55
R244
R
3
1
0
C
1
4
2
DZ4
C89
C29
C141
C125
R11
R81
C32
R169
R164
R62
R208
D
5
C13
D24
R313
R104
C44
R131
X
1
5
C48
C63
R67
C73
R277
R74
D
Z
2
R133
C123
R101
R271
R70
Q20
C
1
4
7
R
2
8
3
R
3
2
7
R4
D83
R
2
8
7
R291
C159
Q
2
4
R73
R35
R99
C28
R
2
6
8
R63
C156
R29
R123
C74
D54
R312
R170
R40
C120
C102
R80
C77
C
1
4
9
C5
R33
R
3
3
9
C62
C60
X3
C46
R103
R258
C
3
3
R351
C55
R
2
0
6
C75
C126
C
1
6
Q26
D20
R202
D42
R
2
9
6
R77
X
1
9
R
2
8
6
R129
C86
R
3
7
R135
DZ24
D64
R97
R273
R132
R124
X
2
R66
C72
C91
R
2
8
0
C
1
5
4
R
2
8
8
R
3
2
8
C58
R68
C143
R130
DZ6
R31
DZ21
Q8
C61
D7
R278
C92
R211
D
Z
2
3
Q
2
8
R
5
R136
R27
R
3
2
4
Q21
D30
R
3
2
6
X
1
4
R272
R91
R42
R
3
3
8
R316
R254
C144
D41
R30
R79
D10
D
Z
1
1
X
1
3
R212
R
3
2
9
R105
D59
R127
R359
R-5
R-2
FIGURE F.2 - CONTROL BOARD TRIMMERS