Lincoln Electric IDEALARC R3R 375-I - Manual (Page 16)

E-4 TROUBLESHOOTING E-4
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
E. Machine does not have
maximum output (67 to 71 volts).
F. Machine comes on but soon trips
off while under load and High
Temperature Warning Light
glows. (Thermostat tripped)
G.Machine comes on but reduces
to low output under load and
remains there until the load is
broken and arc restarted. See
Fault Protection Troubleshooting
Section E.
1. Input fuse blown. Machine is
single phased.
2. One phase of main transformer
windings open.
3. Defective power bridge.
1. Improper ventilation.
2. Loaded beyond rating.
3. Fan inoperative.
4. Shorted diode or SCR in power
rectifier bridge.
1. Excessive load causing the over-
load protection on control board
to operate.
2. Machine output shorted causing
overload protection on control
board to operate.
3. Control circuit defective.
1. Replace fuse or repair input line.
Check reason for fault.
2. Repair.
3. Check bridge per
Troubleshooting Procedures
Section J and check snubber per
Section F.
1. Make sure all case openings are
free for proper circulation of air.
2. Operate at rated current and
duty cycle.
3. Check leads and motor bearings.
Fan can be tested on 115 volt
line.
4. Refer to Troubleshooting
Procedures Section J and
Snubber, Section F.
1. Reduce load.
2. Turn machine off and remove
short.
3. Replace per PC board,
Troubleshooting, Section A.