TM 55-1520-240-T
2-2.4 DYNAMIC ABSORBER SYSTEM OPERATIONAL CHECK (Continued)
2-2.4
TASK
RESULT
1.
2.
3.
4.
5.
Check that LH VIB ABSORB circuit
breaker (1) is closed.
Check that CTR VIB ABSORB circuit
breaker (2) is closed.
Check that RH VIB ABSORB circuit
breaker (3) is closed.
Turn selector switch (4) on test box to
LEFT. Set test switch (5) to RETRACT.
Hold test switch (5) to EXTEND.
6. Hold test switch (5) to RETRACT.
7. Set selector switch (4) to CENTER.
8. Set selector switch (4) to RIGHT.
If circuit breaker (1) is open, close it. If it opens
again, go to task 2-2.7.
If circuit breaker (2) is open, close it. If it opens
again, go to task 2-2.6.
If circuit breaker (3) is open, close it. If it opens
again, go to task 2-2.5.
Hold test switch (5) at RETRACT until meter (6)
pointer stabilizes at about 0. If meter pointer does
not move, set test switch (5) to EXTEND. If
meter still does not Indicate, go to task 2-2.8.
Meter (6) pointer shall move toward EXTEND. It
may initially deflect off-scale. After that, pointer
shall return to average meter deflection (Table 2-
1) and fall to about 0 in the time interval for
temperature (Table 2-1). If meter pointer does not
move to EXTEND go to task 2-2.9.
Meter (6) pointer shall move toward RETRACT.
It may initially deflect off-scale. Meter pointer
shall return to average meter deflection (Table 2-
1). After that, pointer shall fall to about 0 in the
time interval for temperature (Table 2-1). If meter
pointer does not move toward RETRACT, go to
task 2-2.9.
Repeat steps 4 thru 6. If meter (6) pointer does
not move in either direction, go to task 2-2.10. If
meter pointer indicates in one direction only, go to
task 2-2.11.
Repeat steps 4 thru 6. If meter (6) pointer does
not move in either direction, go to task 2-2.12. If
meter pointer moves in one direction only go to
task 2-2.13.
TABLE 2-1
AVERAGE
T I M E
METER
INTERVAL
TEMPERATURE
DEFLECTION
IN SECONDS
+50° F (+10° C)
0.05 to 0.20
50 to 300
and above
-4° F (-20° C) to
0.04 to 0.20
50 to 360
+50° F (+10°C)
-67°F (-55°C) to
0.02 to 0.20
50 to 480
-4°F (-20°C)
FOLLOW-ON MAINTENANCE:
TM 55-1520-240-23:
Battery Disconnected
Electrical Power Off
Hydraulic Power Off
Heater Compartment Acoustic Blanket In-
stalled
9. Set selector switch (4). to O F F.
END OF TASK
Change 1
2-25