Hobart 60PL20, Operation And Maintenance Manual

Page: 98 / 178

TROUBLE, SYMPTOM TEST, CHECK, AND/OR
AND CONDITION PROBABLE CAUSE REMEDY
GENERATOR
1. No (or low) voltage A. Shorted diode in A. Check diodes in accordance
output exciter rectifier with Sect. 2-3, para. 6. If
(CR2). diodes are good, proceed to
step B.
B. Open or shorted exci- B. Use ohmmeter to check for
ter rotor winding open or shorted condition.
(G2) If exciter rotor windings
are good, proceed to step C.
C. Open or shorted exci- C. Check field resistance. See
ter field windings (L2) Sect. 2-3, Fig. 6 for normal values.
D. Open or shorted gen- D. Check resistance with ohm-
erator rotor windings meter to determine if open
(L1) or short circuited.
2. Generator operates A. Open or short cir- A. Check stator winding resis-
single phase cuited winding in tances. See Sect. 2-3, Fig.
generator stator (G1) 6 for normal values.
3. Generator A. Loose connection A. Check all output connec-
overheats causing high resis- tions. Look for discolora-
tance. tion caused by heat. Tighten
or replace as required.
B. Improper or blocked B. Check for foreign material
ventilation. (rags, etc.) blocking air flow.
Provide adequate ventilation.
C. Generator stator C. Check stator windings. See
windings short circuited. Sect. 2-3, Fig. 6.
4. Unbalanced output A. Loose connection in A. Check all output connec-
output circuit. tions. Discolored connectors
indicate a loose connection.
Tighten or replace as required.
B. Open or short circuited B. Check stator windings in
phase accordance with 2-3, Para. 5
Repair or replace as required.
EXTERNAL LOAD
4. Unbalanced output C. Defective connection C. Check plug and receptacle
(Continued) in output circuit. connectors at aircraft.
Tighten, repair, or replace
as required.
D. Break or cut in out- D. Inspect. Repair or replace
put cable assembly. as required.
E. Unbalanced load E. Check aircraft 400-Hz compo-
nents.
OM-2053
3-1 December 31/91 Revised
Page 20