T.O. 35C2-3-442-2
P-9-TM-457-35
TM 5-6115-457-34
TM-07464A-35
4. To isolate a malfunction of the
6-191. INSTALLATION. Refer to figure
electronic components assembly, refer to
6-49 and install the under frequency relay
in the precise relay box. Secure the relay
in position with four screw assemblies,
5. To isolate a malfunction in the
then refer to figure 1-21 and reconnect
real load sharing circuit, measure the re-
wiring. Replace precise relay box and
sistance of rheostat R28. Resistance
cover.
should be adjustable in the range of 15K
ohms 10 percent.
6-192. PRECISE RELAY BOX (A25).
b. Removal. Refer to figure 6-15, dis-
6-193. TEST AND REMOVAL.
connect the two electrical plug connectors
at the precise relay box receptacles, then
a. Symptom and Isolation of Malfunc-
remove the two screws and washers secur-
tion. A malfunction of the precise relay
ing the box in position. Remove the precise
box is usually indicated by a failure of the
relay box.
under frequency relay, under voltage relay,
permissive paralleling relay, electronic
6-194. BENCH TEST.
components assembly, and unequal real
load sharing when the generator set is
a. Refer to table 6-18 and perform a
operated in parallel. To isolate the mal-
continuity and resistance test of the precise
function, refer to figure 1-20 and proceed
relay box.
as follows.
b. Connect the precise relay box to
test equipment as illustrated in figure
6-51 and perform test specified in pro-
WARNING
cedural analysis table 6-19.
Exercise extreme care not to
6-195. DISASSEMBLY. Disassemble the
precise relay box to the extent necessary
touch exposed electrical connec-
to accomplish repair. Refer to figures
tions when working inside precise
6-49 and 6-52 and disassemble in the order
relay box with generator set
operating.
of index numbers assigned. Pay particular
attention to the following.
NOTE
NOTE
Remove cover from precise relay
box to gain access to test points,
Remove the four screws and washers
see figures 6-15 and 6-49.
securing the cover to the relay
chassis.
1. To isolate a malfunction of the
under frequency relay, refer to paragraph
6-189.
a. Tag, then disconnect harness wiring
from components.
2. To isolate a malfunction of the
under voltage relay, refer to paragraph
b. Remove under voltage relay (K11),
6-111.
under frequency relay (K12) and permissive
paralleling relay (16) from the chassis by
3. To isolate a malfunction of the
removing their attaching screw assembles
permissive paralleling relay, refer to
(4 each).
6-150
Change 3
