Lincoln Na5 Service Manual

							F-58TROUBLESHOOTING & REPAIRF-58
TEST PROCEDURE
Perform the following checks with the
NA-5 connected to a Lincoln CV weld-
ing power source according to the prop-
er connection diagram.  See the
Installation Sectionof this manual.
1.  Connect the test voltmeter (see Materials Needed) between the
work and the electrode cable con-
nection at the welding head.  See
Figure F.7
2.  Using the 5/16 nutdriver open the control box PC board access door.  3.  Place a jumper wire between leads
#2 and #4 located on CR3 relay.
See Figure F.8  This this should
energize the output terminals of the
Lincoln CV welding power source.
An open circuit voltage should be
present at the welding output termi-
nals.  The test voltmeter reading
should match the ACTUAL volts
meter reading on the NA-5 within +/-
0.5VDC (typically +/- 0.2VDC).  If it
does not, check the integrity and
placement of the voltage
sensing leads #21 and #67 and
associated wiring.  Perform the
Meter Circuit Accuracy Test.
VOLTMETER ACCURACY TEST (Continued)
NA-5
FIGURE F.7 TEST METER CONNECTION POINTS
CONNECT VOLTMETER
TO ELECTRODE 
CONNECTION
 POINT
ELECTRODE  CABLES



 

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							F-59TROUBLESHOOTING & REPAIRF-59
4.  Remove the jumper wire from leads#2 and #4.
5.  Remove the test voltmeter and, while welding, compare the SET
volts and ACTUAL volts meter read-
ings.  Depending upon the arc volt-
age characteristics of the process
being welded, the ACTUAL reading
may vary somewhat about an aver-
age value.  The average ACTUAL
reading should match the SET read-
ing within +/- 0.5 VDC.  If not, refer
to the 
Meter Circuit Accuracy Test.
6.  If no further tests are required, remove all test equipment and close
and secure the access door.
VOLTMETER ACCURACY TEST (Continued)
NA-5
FIGURE F.8  CR3 RELAY
CR3 RELAY
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							F-60TROUBLESHOOTING & REPAIRF-60
NA-5
WIRE SPEED ACCURACY TEST
TEST DESCRIPTION
This test will help determine if the NA-5 is providing the proper wire f\
eed per inches of revolu-
tion of the drive roll.
MATERIALS NEEDED
Ruler or other linear measuring device
5/16 Nutdriver
Service and repair should be performed only by Lincoln Electric factory trained per-
sonnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precau-
tions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
_____________________________________________________________
WARNING
This procedure takes approximately 20 minutes to perform.
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							F-61TROUBLESHOOTING & REPAIRF-61
TEST PROCEDURE
Perform the following checks with the
NA-5 connected to a Lincoln CV weld-
ing power source according to the prop-
er connection diagram.  See the
Installation Sectionof this manual.
1.  Check to make sure the speedmeter calibration  jumper is connected to
the proper calibration pin for the
head and drive roll system being
used.  See Table F.3 
WIRE SPEED ACCURACY TEST (Continued)
NA-5
SPEEDMETER  HEAD 
DRIVE ROLL WIRE SIZE RANGE RATED SPEED
CALIBRATION RATIO PART NUMBER RANGE (IPM)
21* 21/1 S12778 Single  .035 - .052 Solid 100 - 2070
S19113 Single .045 - .052 Cored
57F** 57/1 S12778Single  .035 - .052 40 - 778
57** 57/1 S12515 Single 1/16 - 3/32 38 - 762
95 95/1 S12514 Single 3/32 - 5/32 22 - 428
95S*** 95/1 S12515 Single 1/16 - 3/32 23 - 456 S19113 Single .045 - .052 Cored
S13161-052 Twin .045 -.052
S13161-5/64 Twin  1/16 - 5/64
S14904 (Outer) Twin 3/32 S14905 (Inner)
142 142/1 S12514 Single 3/32 - 7/32 15 - 289
142T*** 142/1 S14904 (Outer) Twin 5/64 - 1/8 15 - 300 S14905 (Inner)
TABLE F.3
* Present on HI -Speed NA-5 speedmeter board only.   ** Early speedmeter\
 pins were labeled 55F and 55, respectively.
*** Early speedmeter PC boards did not include these calibration pins.
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							F-62TROUBLESHOOTING & REPAIRF-62
2.  Check for the proper wire feed inch-es per revolution of the drive roll.
A.  Set the Strike speed control to any setting between 50 and 125
IPM.  While pressing the INCH
DOWN button measure the pre-
cise length of wire fed by exactly
10 revolutions of the drive roll.
The measured length should be
within the range specified in
Table F.4  for the drive roll and
wire size employed. B.  If the measured length is not
within the specified lengths
there may be a problem with the
wire or wire feeding path.  See
the 
Troubleshooting Guide
(Feeding Problems)
in this sec-
tion of the manual.  Also check
for correct drive roll tension
adjustment.
WIRE SPEED ACCURACY TEST (Continued)
NA-5
DRIVE ROLL PART 
WIRE SIZE RANGEINCHES OF WIRE FED PER
NUMBER 10 REVOLUTIONS OF
DRIVE ROLL
S12778 Single  .035 - .052 Solid 53 - 54
S19113 Single  .045 - .052 Cored 53 - 55
S12515 Single  1/16 - 3/32 51 - 53
S12514 Single  3/32 - 5/32 49 - 51
S13161-052 Twin  .045 - .052 53 - 55
S13161-5/64 Twin  1/16 - 5/64 53 - 55
S14904 (Outer) Twin  3/3251 - 52
S14905 (Inner)
S12514 Single  3/32 - 7/32 49 - 52
S14904 (Outer) Twin  5/64 - 1/8 51 - 53
S14905 (Inner)
TABLE F.4
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							F-63TROUBLESHOOTING & REPAIRF-63
3.  Check for the proper drive roll revo-lutions per minute. (RPM)A.  Adjust the STRIKE speed con- trol to obtain the SET speed
specified for the speedmeter
calibration pin and head ratio
specified per Table F.5  While
pressing the INCH down button
count the drive roll revolutions in
60 seconds.  The drive roll revo-
lutions and actual speed reading
should match Table F.5   B.  If the readings do not match the
number in Table F.5  refer to the
Meter Circuit Accuracy Test.
WIRE SPEED ACCURACY TEST (Continued)
NA-5
SPEEDMETER  HEAD SET SPEEDMETER DRIVE ROLL ACTUAL
CALIBRATION  RATIO READING  (IPM)RPM SPEEDMETER
PIN READING (IPM)
21* 21/10.27 (IPM X 1000) 50 +/- 2 0.27 +/- 0.01 
(IPM X 1000)
57F** 57/1 26850 +/- 1268 +/- 2
57** 57/1 26250 +/- 1262 +/- 2
95 95/1 24950 +/- 1249 +/- 2
95S*** 95/1 26550 +/- 1265 +/- 2
142 142/1 25050 +/- 1250 +/- 2
142T*** 142/1 26050 +/- 1260 +/- 2
TABLE F.5
* Present on HI -Speed NA-5 speedmeter board only.   ** Early speedmeter\
 pins were labeled 55F and 55, respectively.    
*** Early speedmeter PC boards did not include these calibration pins.
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							F-64TROUBLESHOOTING & REPAIRF-64
NA-5
METER CIRCUIT ACCURACY TEST
TEST DESCRIPTION
This test will help determine if the NA-5 meter circuit is functioning p\
roperly.
MATERIALS NEEDED
Digital volt/ohmmeter with at least 3-1/2 digits and +/- 0.5% accuracy 
5/16 Nutdriver
Service and repair should be performed only by Lincoln Electric factory trained per-
sonnel. Unauthorized repairs performed on this equipment could result in danger to
the technician or the machine operator and will invalidate your factory warranty. For
your safety and to avoid electrical shock, please observe all safety notes and precau-
tions detailed throughout this manual.
If for any reason you do not understand the test procedures or are unable to perform
the tests/repairs safely, contact the Lincoln Electric service department for technical
troubleshooting assistance before you proceed.
Call (216) 383-2531 or (800) 833-9353 (WELD).
_____________________________________________________________
WARNING
The Speed Meter Circuit tests take  approximately 15 minutes to perform.\
The Volt Meter Circuit tests take  approximately 15 minutes to perform.
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							F-65TROUBLESHOOTING & REPAIRF-65
TEST PROCEDURE
1.  Remove input power to the NA-5.
2.  Using the 5/16 nutdriver open thecontrol box PC board access door.
3.  Locate the voltmeter PC board.  See Figure F.9
4.  Apply input power to the NA-5. 5.  
Test for AC supply to the volt-
meter PC board .
• Check for 8 to 11VAC from lead #601 to #602. See Figure F.9
Note: The coating will have to be
removed from the test points to ensure
accurate voltmeter readings.  If the cor-
rect AC voltage is not present check for
loose or faulty connects with the associ-
ated leads.  See wiring diagram.
METER CIRCUIT ACCURACY TEST (Continued)
NA-5
FIGURE F.9  VOLTMETER PC BOARD AND TEST POINTS
L6685-[ ] METER
TP4
TP5 517
518
510 510C
601
602
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							F-66TROUBLESHOOTING & REPAIRF-66
6.  Test for DC volts on the voltmeter
PC board.
• Check for 4.75 to 5.25VDC from TP5 to lead #510C.  See Figure
F.9
Note:  The coating will have to be
removed from the test points to ensure
accurate voltmeter readings.   • If the display is NOT lit and thecorrect DC voltage is present at
TP5 to lead #510C, the digital
meter may be faulty.  Replace the
meter.
• If the AC voltage IS present at leads #601 to #602 and the DC
voltage is missing,  the voltmeter
PC board may be faulty. 7.  
Test Digital Voltmeter Accuracy
• Use a test meter with at least 3- 1/2 digits and +/- 0.5% accuracy.
• Connect the + probe to TP4 and the - probe to lead 510C.  Do NOT
disconnect plug.
Note:  The coating will have to be
removed from the test points to ensure
accurate meter readings. • With the NA-5  voltmeter readingSET values of STRIKE voltage,
adjust the strike voltage control
until the test meter matches the
settings in the table below.
• If the NA-5 digital voltmeter does not match the readings, the digital
meter may be faulty.
METER CIRCUIT ACCURACY TEST (Continued)
NA-5
NA-5 SET VOLTS READING TEST VOLTMETER READING
15.0VDC
.150 +/- .004VDC
30.0VDC.300 +/- .004VDC
60.0VDC .600 +/- .006 VDC
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							F-67TROUBLESHOOTING & REPAIRF-67
8. Test Voltmeter PC Board Accuracy
• Use a test meter with at least 3-1/2 digits and +/- 0.5% accuracy.
• Connect the + probe to lead #517 and the - probe to lead #510C.
Do not disconnect plug.  
Note:  The coating will have to be
removed from the test points to ensure
accurate meter readings. • With the NA-5  voltmeter readingSET values of STRIKE voltage,
adjust the strike voltage control
until the NA-5 voltmeter matches
the settings in the table below.
• If the test meter does not match the readings, the voltmeter PC
board may be faulty.
METER CIRCUIT ACCURACY TEST (Continued)
NA-5
NA-5 SET VOLTS READING TEST VOLTMETER READING
15.0VDC
1.50VDC +/- .04
30.0VDC3.00VDC +/- .04
60.0VDC 6.00VDC +/- .06
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