Troubleshooting & repair, Engine throttle adjustment test (continued) – Lincoln Electric COMMANDER 400 SVM133-B Manuel d'utilisation
Page 93
TROUBLESHOOTING & REPAIR
F-39
F-39
COMMANDER 400
ENGINE THROTTLE ADJUSTMENT TEST
(continued)
6. If either of the readings is incorrect, adjust
the throttle as follows:
Adjust HIGH IDLE: Use the 10mm wrench to
loosen the locking nut. See Figure F.11 for
location of the adjusting screw and locking nut.
Turn the threaded screw counter-clockwise to
increase the HIGH IDLE speed. Adjust the
speed until the tach reads between 1890 and
1915 RPM. Retighten the locking nut.
Adjust LOW IDLE: First make sure there is no
load on the machine. Set the IDLE switch to
AUTO and wait for the engine to change to low
idle speed. Use the 7/16" wrench to loosen the
solenoid lever arm locking nut. See Figure
F.12.
Adjust the collar, to change the amount
of throw in the lever arm, until the tach reads
between 1325 and 1400 RPM. Retighten the
locking nut.
Frequency Counter Method
1. Plug the frequency counter into one of the
115 VAC auxiliary receptacles.
2. Start the engine and check the frequency
counter. At HIGH IDLE (1900 RPM), the
counter should read 63 Hz. At LOW IDLE
(1400 RPM), the counter should read 47 Hz.
Note that these are median measurements;
hertz readings may vary slightly above or
below.
3. If either of the readings is incorrect, adjust
the throttle as follows:
Adjust HIGH IDLE: Use the 10mm wrench
to loosen the locking nut. See Figure F.11
for location of the adjusting screw and lock-
ing nut. Turn the threaded screw counter-
clockwise to increase the HIGH IDLE speed.
Adjust the speed until the frequency reads
63 Hz. Retighten the locking nut.
Adjust LOW IDLE: First make sure there is
no load on the machine. Set the IDLE
switch to AUTO and wait for the engine to
change to low idle speed. Use the 7/16"
wrench to loosen the solenoid lever arm
locking nut. See Figure F.12. Adjust the
collar, to change the amount of throw in the
lever arm, until the frequency reads 47 Hz.
Retighten the locking nut.
Oscilloscope Method
1. Connect the oscilloscope to the 115 VAC
receptacle, according to the manufacturer’s
instructions. At HIGH IDLE (1900 RPM), the
waveform should exhibit a period of 15.8
milliseconds. At 1400 RPM, the waveform
should exhibit a period of 21.4 milliseconds.
Refer to the NORMAL OPEN CIRCUIT
VOLTAGE WAVEFORM (115 VAC AUXIL-
IARY) HIGH IDLE - NO LOAD in this sec-
tion of the manual.
2. If either waveform periods is incorrect,
adjust the throttle as follows:
Adjust HIGH IDLE: Use the 10mm wrench
to loosen the locking nut. See Figure F.11
for location of the adjusting screw and lock-
ing nut. Turn the threaded screw counter-
clockwise to increase the HIGH IDLE speed.
Adjust the speed until the period is 15.8 mil-
liseconds. Retighten the locking nut.
Adjust LOW IDLE: First make sure there is
no load on the machine. Set the IDLE
switch to AUTO and wait for the engine to
change to low idle speed. Use the 7/16"
wrench to loosen the solenoid lever arm
locking nut. See Figure F.12. Adjust the
collar, to change the amount of throw in the
lever arm, until the period is 21.4 millisec-
onds. Retighten the locking nut.