Lincoln Electric R3R 375-I Welder User Manual


 
E-5
TROUBLESHOOTING
E-5
IDEALARC® R3R 375-I, 500-I AND 600-I
Observe all Safety Guidelines detailed througout this manual
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local
Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
CAUTION
FUNCTION PROBLEMS
PROBLEMS
(SYMPTOMS)
POSSIBLE CAUSE
RECOMMENDED
COURSE OF ACTION
H.Machine trips off when under no
load or makes excessive noise
like it is loaded.
I. Variable or sluggish welding arc.
J. Welder will not shut off.
K. Current control on machine not
functioning.
1. Power bridge rectifier may have
a shorted diode or SCR.
2. Short in the transformer.
3. Fan hitting vertical baffle.
1. Poor work or electrode cable
connection.
2. Current too low.
3. Welding leads too small.
4. Open SCR or diode in power
rectifier bridge.
5. Control circuit problems.
1. Input contactor contacts frozen.
1. Current control switch in wrong
position.
2. Current control switch defective.
3. Current control potentiometer
defective.
4. Lead or connection in control
circuit open.
5. Defective control or circuit
boards.
1. Refer to Power Hybrid,
Troubleshooting Procedures,
Section J and Snubber, Section
F.
2. Repair.
3. Clear the fan.
1. Check and clean cable connec-
tions.
2. Check recommended currents
for rod type and size.
3. See Table in Output Connection
Section.
4. Check per Power Rectifier
Bridge Troubleshooting
Procedures, Section J and
Snubber, Section F.
5. See SCR Troubleshooting,
Section K.
1. Replace input contactor.
1. Place switch in “machine” ( I )
position.
2. Check per Section H.
3. Check per Section G.
4. Repair or connect.
5. See SCR Troubleshooting,
Section K.