TM 5-3431-207-15
Item
Par. ref.
WIRING, RESISTORS, SWITCHES. Check switches to see that they are operat-
1
ing properly and if they are properly installed. Check wiring for frayed, oil-soaked,
or deteriorated insulation, broken wires and loose or damaged connections.
Clean corroded and tighten loose connections. Replace defective switches
and resistors.
VOLT-AMP METER. Inspect the volt-amp meter for cracked or broken glass,
2
loose mounting screws and replace missing mounting screws. Adjust the volt-
amp meter. Replace any damaged or defective meter and calibrate as necessary.
FRAME AND SUBBASE. Check frame and subbase for broken welds, tears, loose
3
or missing assembly bolts and nutsRepair all broken welds and tears. If a
damaged wheel is discovered, it should be replaced, if it is beyond repair.
BRUSHES AND COLLECTOR RINGS. Inspect collector rings for dirty or rough
4
surfaces. Inspect brushes for a worn condition. Inspect electrical leads for a
worn or unserviceable conditionInspect brush springs for improper tension.
Inspect brush holders for insecure mounting hardware. Tighten all loose elec-
trical connections or brush holdersReplace worn or damaged brushes. Adjust
brush spring tension as necessary.
CIRCUIT BREAKER. Inspect the mounting, wiring and operation of the circuit
5
breaker. Inspect for excessive accumulation of corrosion on the terminals. In-
spect for defective wiring and broken or loose connections. Clean all corrosion
from the circuit breaker terminals. Tighten all loose connections. If a defective
circuit breaker is present, replace immediately.
CONTROL PANEL AND INSTRUMENTS. Inspect all instruments for cracked
6
or broken glass. Inspect for insecure mountings, loose connections, and improper
operation. Inspect control panel for cracks, breaks and other damage. Tighten
all loose mountings and electrical connections. Inspect electrical leads for a cor-
roded condition. Replace any and all defective instruments such as current con-
trol, job selector, and remote control.
MOTOR-GENERATOR. Inspect the motor-generator very carefully. The motor-
7
generator should be serviced quarterly or as necessary.
Figure 8. Quarterly preventive maintenance.
Section III. TROUBLESHOOTING
causes of trouble shown in the left-hand column. The
31. General
possible remedy recommended is given opposite the
Paragraphs 32 through 35 provides information useful in
cause in the right hand column.
diagnosing and correcting unsatisfactory operations or
failure of equipment or any of its components. Each
32. Motor Fails to Hold the "Heat" Constantly
trouble symptom stated is followed by a list of probable
Probable cause
Possible remedy
Electrode Lead or work lead connections
Tighten all connections.
may be poor.
Field rheostat may be making poor
Inspect rheostat and clean or replace (par.
contact and overheating.
Brushes may be worn down to limit of
Replace brushes (par. 37).
adjustment or life.
Brush springs may have lost adjustment
Replace or readjust brush springs (par. 39).
or may be broken.
Current control brush holder support stud
Clean off brush holder stud and internal
and mating contact surfaces may be
contact surface use light application of
dirty or pitted and burned.
vasoline to stud and replace. If brush
holder internal contact surface is burned,
replace brush holder and support stud
17
