TM 55-4920-410-13&P
CHAPTER 3
OPERATING INSTRUCTIONS
Section I. OPERATOR’S CONTROLS AND INDICATORS
3-1. Operator’s Controls.
All operator’s controls and indicators are shown in
Figure 3-1 and listed and described in Table 3-1.
Section II. OPERATION UNDER USUAL CONDITIONS
3-2. Preliminary Starting Procedure.
a. Place helicopter GENERATORS APU switch to
OFF/RESET.
b. Place GEN, CUR. LIM, and FF switches OFF.
Place all other toggle switches to down position. Place
TEST SELECT switch to START TEST. Check that
circuit breakers are pressed.
c. Connect grounding cable to ground jack on test set
and attach alligator clip to suitable ground on helicop-
ter chassis.
d. Attach connector P1 of the adapter cable to
AIRCRAFT connector J1 on test set.
e. Disconnect connector P1 from GCU in helicopter.
Attach connector P3 of adapter cable to connector P1
that was disconnected from GCU.
f. Attach connector P2 of adapter cable to connector
J1 of GCU.
g. Make sure APU CONTR INST circuit breakers
are in.
3-3. Operating Procedures
Do an operational check of ac electrical system (TM
55-1520-237-23-3.)
3-4. Shutdown Procedure.
a. Place GEN switch OFF.
b. Check that TEST SELECT
TEST.
switch is at START
c. Place helicopter GENERATOR APU switch to
OFF/RESET.
d. Disconnect adapter cable from helicopter wiring.
e. Attach helicopter connector to connector J1 of
GCU.
f Disconnect grounding cable from test set and from
helicopter.
3-1
