NAVELEX EE181-AA-OMI-030/E121 RT1161 M9443
wire is not caught under board. Insert screws
Remove enough conduit clamps to swing
through PC board, and tighten them to secure
Transceiver chassis away from the mounting
board. Connect black ground lead to pin near
surface. Remove screws that secure transducer
tamper alarm switch. Connect transducer leads
mounts to sides of the chassis. From the rear of
to pins at each end of PC board. Replace
the housing, remove screws that secure the
Transceiver housing cover.
transducer mount to the rear panel of the
chassis. Remove the transducer mount. Use a
7/8-inch (2.23 cm) rod, such as a wooden dowel,
assemblies, test the UMS for proper operation
to press against the screened end of the
under worst case conditions, with all noise or
transducer, and press it out of the mount.
turbulence-producing equipment in operation.
Remove the plastic washer. Disconnect leads
Ensure that key-operated switch on Control Unit
from rear of the transducer.
is in access position. Remove the Processor
chassis cover, and pull the TAS plunger all the
f. To replace a transducer, match dot color on
way out. Disconnect the wire from TB1-1. Set
transducer with dot color on mount; blue for
multimeter to ohms and connect leads to TB1-1
receive and white for transmit. Put top side of
and TB1-2. Meter should indicate less than
mount against a flat surface, and align
2,000 ohms. Walk into the secure area. The
transducer with underside of mount. Use heel
meter indication should change to over 100,000
of hand to press transducer into mount until
ohms. Remain motionless for several seconds
shoulder around bottom of transducer is flush
and the meter indication should return to its
against bottom on mount. Use a 7/8-inch (2.23
Connect wire to TB1-1.
cm) rod, such as a wooden dowel, to press
Disconnect wire from TB1-2, and connect meter
plastic washer down inside mount until it is flat
leads to TB1-5 and TB1-6.
against screened end of transducer. To match
indicate less 2,000 ohms. Remove the four
leads to the transducers, note that the transmit
screws securing the Transceiver chassis cover.
transducer (white dot) requires 8-inch (20.32
Slowly raise the cover. While the cover flanges
cm) leads and that the receive transducer (blue
are still engaged, the meter indication should
dot) requires 3 1/2-inch (8.89 cm) leads. Ensure
change to over 100,000 ohms. Remove cover.
that transducer leads have approximately one
Pull TAS plunger all the way out. The meter
twist per inch (2.54 cm). Connect leads to rear
indication should return to its original level.
of transducer. Place transducer mount inside
Replace the Transceiver chassis cover, and
chassis and insert two screws through rear panel
secure it with screws. Use a straightedge
and into mount. Insert screws through sides of
across the Processor chassis to depress the
chassis and into transducer mount. Tighten the
TAS plunger. The meter should indicate less
screws to secure the mount in the chassis.
then 2,000 ohms. Slowly raise the straightedge.
Swing chassis against mounting surface, secure
When the TAS plunger moves 1/4-inch or less,
with mounting hardware, and replace conduit
the meter indication should change to over
clamps. Shift PC board off center toward
100,000 ohms. Disconnect the meter leads
receive transducer (blue dot). Align single
from TB1-5 and TB1-6 and connect the wire to
screw hole in board with screw hole in center of
TB1-2. Replace the Processor chassis cover
receive transducer mount. Ensure that black
and secure it.