111. NO R4 FIELD RHEOSTAT CONTROL USING
or defective armature on
Rheostat regulator switch
Place in REGULATOR posi-
S25 in RHEOSTAT posi-
Rheostat switch S16 in
Place in BATT. GEN posi
Place in ON position.
TEST GEN position
Load switch S39 in OFF
Rheostat regulator switch
(25) or rheostat switch
Variable control R1 in
Turn counterclockwise to
112. NO INVERTER-LOAD.
Open load resistor ..............Check load rack and
replace as necessary
Inverter switch S24 in OFF Put in ON position.
or CENTER position
Defective de generator
Dirty or pitted normally-
Clean contacts with bur-
load switch S39
open contacts on relay
Section III. CONTROL PANEL AND FRONT PANEL ASSEMBLIES
Maintenance to be performed on control panel
(3) Remove relay clamping post (3) and two
relay mounting studs (4) from upper right section of
relay mounting pad (13). Remove upper back plate (5)
from pad by removing two screws (6) securing plate to
115. RELAY PAD.
rear of relay mounting pad.
(4) Remove remaining relay clamping post
(1) Tag and disconnect electrical leads from
(3) and relay mounting stud (4) from relay mounting pad
(2) Remove external impedor box (1'8) from
(5) Remove nut (9) and screw (8) securing
panel by removing four nuts (22), spacers (21), flat
lower back plate (7) to rear of relay mounting pad, and
washers (20), and capscrews (19), securing external
remove plate from pad.
impedor box to frame of control panel.
(6) Remove GEN + binding post (11) from
(3) Tag and remove electrical leads from
front of relay mounting pad (13) by removing jamnut
terminals on rear of relay pad assembly (27).
(10) and three special nuts from post.
(4) Remove nut (24) and capscrew (23)
(7) Unscrew thumb knob (14) from blinding
securing bus bar (30) to bus bar (36).
post (11) and remove lug clearance washer (12).
(5) Remove bus bar (30) from rear of GEN +
(8) Remove BAT + binding post in a similar
terminal by removing jamnut and two special nuts.
(6) Remove bus bar (31) by removing screw
c. Cleaning and Inspection.
(25), jamnut, and two special nuts from BATT + terminal
(1) Clean parts with dry cleaning solvent P-D-
on rear of relay pad assembly.
680 and dry thoroughly.
(7) Remove bus bar (26) by loosening thumb
(2) Inspect thumb knobs and binding posts for
knobs on BATT + and GEN + terminals.
cracks, breaks, or distorted condition.
(8) Remove relay pad assembly (27) from
(3) Inspect threaded parts for worn or
and screws (28) securing relay pad assembly to the
(1) Install lug clearance washer (12) and
thumb knob on GEN + binding post (11).
(1) Remove GND binding post (1) from relay
mounting pad (13, figure 9) by removing nut (2) from
(2) Attach binding post on front of relay
mounting pad (13) with three special nuts and jamnut
(2) Remove APP and SW binding posts in