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...

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...

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...

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...

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...

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...

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...

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...

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...

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...