TM 11-6625-444-14-2
Section IV. MAINTENANCE OF THE VOLTMETER
6-8. General
(2) Raise the cover slightly at the rear and
then slide it forward far enough to clear the bot-
tom flange of the front panel.
This section contains maintenance instructions
for the voltmeter. The information is arranged
under paragraphs covering disassembly, clean-
(3) Lift the bottom cover from the voltme-
i n g , repair and replacement, assembly, and
ter.
component selection. Contents of these para-
graphs provide complete maintenance instruc-
tions for the voltmeter. The performance tests
c. Top Guard Cage Cover Removal
starting with paragraph 6-13 shall be conducted
after any repairs are made.
(1) Unscrew the nine 4-40 screws secur-
ing the top guard cage covers. Two are located
CAUTION
at the front of the cover, two are located at the
rear and the remaining five unscrew from stand-
offs mounted on the True Rms Converter assem-
No instructions for internal calibration
bly.
are provided in this manual. Refer
to TB11-6625-444-50-2. Do not
disturb any internal adjustments when
(2) Lift the cover plate and remove it from
covers are removed.
the voltmeter.
d. Bottom Guard Cage Cover Removal
(1) Turn the voltmeter upside down and
WARNING
unscrew the eight 4-40 screws securing the
bottom guard cage cover.
AC mains voltage connections are
used within the voltmeter. Be care-
(2) Lift the cover plate and remove it from
ful when working on equipment if
the voltmeter.
covers are removed and power cable
is plugged into ac power outlet.
e. True Rms Converter Board Assembly (A7)
Removal
a. Top Dust Cover Removal
(1) Carefully unplug the center conductor
. Refer to figure
lead (A7-R1) from terminal
(1) Remove the top dust cover by first un-
screwing the four 6-32 screws.
(2) Raise the cover slightly at the rear and
(2) Carefully unplug the shield lead (A7-
then slide it forward far enough to clear the top
. Refer to figure 6-11.
R163) from terminal
flange of the front panel.
(3) Disconnect connector A7-J35.
(3) Lift the top cover from the voltmeter.
(4) Unscrew the two 4-40 screws that se-
b. Bottom Dust Cover Removal
cure the front mounting bracket to the front of
the guard cage.
(1) Turn the voltmeter upside down and
remove the two 6-32 screws located at the rear
o f the dust cover that secure the rear feet.
(5) Unscrew the 4-40 screw located at the
r e a r left corner of the True Rms Converter
Remove the other two 6-32 screws retaining the
board.
sides of the cover.
