NAVELEX EE 181-AA-OMI-060/E121 SA-1955
Section III. GENERAL MAINTENANCE
the Actuating Magnet Assembly and the Bias Magnet
5-4. MAINTENANCE ACTION. The extent of direct and
Assembly. Inspection and service are provided for the
general support maintenance is governed by the
enclosure. Periodic testing of the Balanced Magnetic
Maintenance Allocation Chart (MAC), Appendix B. The
Switch is not scheduled because the J-SIIDS is
MAC provides for on-site test and replacement of the
maintained in continuous operation.
PC board, Actuating Magnet Assembly and Bias Magnet
Assembly. On- site test and adjustment are made on
Section IV. REMOVAL AND REPLACEMENT OF MAJOR COMPONENTS AND ASSEMBLIES
5-5. REMOVAL AND INSTALLATION PROCEDURES.
f. To install a new Actuating Magnet Assembly,
turn the assembly so the notches in the end of
a. To remove the PC board, tag and disconnect
the housing face the same direction as the
the wires from TB1. Remove two screws that
notch in the Magnetic Switch Assembly housing.
secure PC board to the housing. Remove the
Align the screws holes in the inner half of the
Actuating Magnet Assembly with the screw
holes in the mount- ing surface.
b. To install new PC board, orient the board so
tighten two screws to secure this half of the
that the terminal strip is on the side away from
assembly to the mounting surface. Place the
the Actuating Magnet. Secure the board to the
outer half of the Actuating Magnet Assembly
housing with two screws. Connect the wires to
over the inner half. Ensure that the notches in
the housing are aligned. Insert and tighten two
screws to secure the outer half of the assembly.
To remove the Bias Magnet Assembly, remove
the two screws that secure the Bias Magnet
g. After removal and replacement of major
Assembly to the PC board. Remove the Bias
components or assemblies, calibrate the BMS
for proper operation. Disconnect wires from
TB1-1 and 2. Set multimeter to ohms and
d. To install a new Bias Magnet Assembly, put it in
connect leads to TB1-1 and 2. With door or
place on the PC board. Start the two screws
window closed, meter should indicate less than
that secure it, but leave these screws loose so
50 ohms. Open the door or window 1 1/4 inch
the bias magnet can be calibrated.
(3.175 cm) or more. Meter indication should
change to an open circuit or infinity. Connect the
e. To remove the Actuating Magnet Assembly,
meter leads to TB1-5 and 6. Meter should
remove the two screws from the outer half of
indicate more than 100,000 ohms. Depress the
the assembly. Remove the outer half of the
TAS arm. The meter indication should change
assembly. Remove and keep the two screws
to less than 50 ohms. Connect the wires to TB1
that secure the inner half of the Actuating
and install the cover.
Magnet Assembly to the mounting surface.
Remove the inner half of the assembly.