b. Plug the power test set prods into the inverter test
(8) R e p l a c e t h e
point jacks, and apply power to the inverter.
3-10. Adjustment of Output Frequency
to figure 3-1 and adjust
L1 (or R3) for
Output frequency potentiometer L1 on CSV2215-3 (R3
dication of 400 Hz.
on CSV1186-1), and R5 on 4B93-1-A is used to estab-
Check for variation
between no load
lish the 400 Hz ac output current. Follow the procedure
and full load conditions. A variation of less than 8 Hz is
below for adjustment.
e. Disconnect power test set prods, and replace
This procedure can be carried out in the
aircraft if the inverter can be reached easily.
a. Remove the regulator cover.
Section IV. DIRECT SUPPORT TESTING PROCEDURES
3 - 1 1 . General
level to accept the 4B93-1-A regulator. These units can
be identified by the letter "M" stamped on the data
These testing procedures have been prepared for use by
plate. For a listing of recent MWO's refer to DA Pam
direct support maintenance shops to determine the ac-
ceptability of repaired equipment. These procedures
set forth specific requirements that repaired equip-
3-13. Tests and Procedures
ment must meet before being returned to the using
Equipment which meets the performance standards in
tables 3-2 and 3-3
may be considered acceptable for
3-12. Modification Work Orders (MWO's)
service. Perform each step in sequence. For each step,
perform all the actions in the Control settings column,
At the time of this publication, there were no printed
then perform the specific procedure and verify it
MWO's pertaining to this equipment. However, inver-
against its performance standard.
ters, as they are received, are being modified at depot
Table 3-2. Physical Tests and Inspections
No dust, grease, dirt or carbon parti-
Inspect exterior and interior for
cles on surfaces.
a. Screws, bolts, and nuts will be
a. Inspect mechanical assem-
tight; none missing.
blies for loose or missing
screws, bolts, or nuts.
b. Inspect ac connector and test
b. No looseness or damage evident.
points for looseness and
a. Inspect all components for
a. None evident.
b. No looseness evident.
b. Check regulator for security
c. No looseness evident.
c. Check all leads inside unit for
Brushes are in good condition and
Check each ac contact brush in
seating is satisfactory. Refer to
turn for proper condition and
Be sure that all toggle switches
are in the OFF position and
connect equipment as shown in
Zero all teat set meters, if neces-
Adjust power supply to 27.5 vdc
on test set dc VOLTS meter.