TM 55-4920-428-13
NOTE
The POWER indicator is in the upper section of the LAMP TEST switch,
b. In turn, press and release SAS 1 and SAS 2 FEEDBACK SELECT, CYCLE MOTOR, and SOLENOID
SHUTOFF switches. In each switch, the lighted indicator shall go out. Both lamps in the unlit indicator shall
come on. If necessary, press and release each switch so that the upper indicator comes on.
c. Momentarily press the LAMP TEST switch. Both lamps in lower indicators of the five switches shall come
on.
d. Press and release the SAS 1 FEEDBACK SELECT switch. The CROSS indicator shall come on and the
shelf indicator shall go out,
e. Press and release the SAS 2 FEEDBACK SELECT switch. The CROSS indicator shall come on and the
self indicator shall go out.
f. Press and release the CYCLE MOTOR switch. The OFF indicator shall come on and the ON indicator
shall go out.
g. Press and release the SOLENOID SHUTOFF switch. The CLOSED indicator shall come on and the open
indicator shall go out.
h. Momentarily press the LAMP TEST switch. The lower (warning) indicator of the TEST switch and the
upper indicators of the other four switches shall come on.
4-46. Undervoltage Detection Circuit Test.
This test ensures undevoltage detector circuit functions as re-
quired.
a. Reduce the autotransformer output voltage until the WARNING indicator comes on. The autotransformer
voltmeter shall indicate 103 to 107 volts ac.
b. Reduce the autotransformer output until its voltmeter indicates 100 volts ac.
c. Increase the autotransformer output until the WARNING indicator goes out. The voltmeter shall indicate
103 to 107 volts ac.
d. Increase the autotransformer output voltage until its voltmeter indicates 115 volts ac.
4-47. SAS 1 Self-Feedback and Metering Circuits Test.
This test ensures the SAS 1 self-feedback and me-
tering circuits function as required.
a. Set the power switch to OFF.
b. Connect the 2,000 ohms 1W 0.1% load resistor to receptacle pins J1-8 and J1-10 (FO-1 for pin pattern).
c. Connect a jumper wire to receptacle pins J1-3 and J1-4.
d. Connect a jumper wire to receptacle pins J1-13 and J1-14.
e. Set No. 2 multimeter to measure dc volts. Connect it to the SAS 1 EXTERNAL METER + and – jacks.
f. Set the power switch to ON.
g. Press SAS 1 FEEDBACK SELECT switch to SELF.
h. Adjust SAS 1 VALVE CONTROL until the DVM indicates –0.09 to +0.09 volt. Check that No. 2 multim-
eter indicates -0.03 to +0.03 volt.
Change 3
4-17
