TM 55-4920-431-13
Controls and Indicators
Item
Function
Nomenclature
Displays % engine speed from 0 to 120
1
SPEED meter
Displays exhaust gas temperature (EGT)
2
TEMP meter
in F from 0 to 1500
Controls 28 VDC power to tester and ESU
3
MASTER switch
4
Initiates start sequence of ESU and gener-
START/RUN/STOP
ates start signal input to tester
switch
(Not applicable)
5
BLEED AIR OPEN/
CLOSE switch
(Not applicable)
6
OVERSPEED TEST
switch
(Not applicable)
7
MAX. AIR switch
(Not applicable)
8
ECONO AIR switch
Selects local or remote analog converter.
LOCAL/REMOTE
9
LOCAL (down position) selects analog con-
switch
verter in aircraft. REMOTE (up position)
selects analog converter in tester. Always
left in the REMOTE position.
To monitor magnetic pickup input and input
TACH INPUT jacks
10
simulation signals
(Not applicable)
BLEED VALVE
11
VOLTS/CURRENT
jacks
Color coded LED
12
indicators
BYPASS
Lighted indicates voltage is applied to
a.
start bypass valve.
Lighted indicates main power is on
b. MAIN POWER
Lighted indicates malfunction has occurred
c.
MALF
and unit is shut down. Bite indication on
ESU is checked for cause
d.
Lighted indicates APU is ready to accept
READY TO LOAD
load
