ARMY TM 9-6115-604-12
NAVY NAVFAC P 8 633-12
4-112. FREQUENCY DROOP/ISOCHRONOUS SWI TCH S117 (12, Figure 2-2). This is a double pole, double throw
switch. The switch is used to select Isochronous or droop generator set operation.
a.
Test.
(1) Tag and disconnect wiring from the FREQUENCY DROOP/ISOCHRONOUS switch S117.
(2) Place switch In FREQUENCY DROOP position.
(3) Set a multimeter to RX1 scale and test for continuity across terminals. Multimeter should indicate zero ohms
across terminals 1-2 and 4-5. Multimeter should indicate infinity across terminals 2-3 and 5-6.
(4) With switch in ISOCHRONOUS position, multimeter should indicate Infinity across terminals 1-2 and 4-5 and
zero ohms across terminals 2-3 and 5-6.
(5) Mechanical operation should display positive latching In both positions.
b. Remove. See Figure 4-66.
(1) Tag and disconnect wiring from the FREQUENCY DROOP/ISOCHRONOUS switch S117 (11).
(2) Unscrew ring nut at front of cabinet B door.
(3) Remove switch (11) from rear of cabinet B door.
c.
Install. See Figure 4-66.
(1) Position switch (11) in door cabinet B and secure with ring nut provided.
(2) Repeat test of step a, above, to be sure switch has not been Installed upside down.
(3) Connect wires and discard tags.
4-113. LOCAL REMOTE SWITCH S2 (23, Figure 2-2). LOCAL REMOTE switch S2 Is a ten-section rotary, double-pole
switch. Detent action provides positive indexing In the LOCAL or REMOTE position. The switch is used to select
whether controlling functions of generator set are to be at generator set control room or remote control module.
NOTE
Switch wirng position numbers are translated as follows the first digit defines the section,
or deck, in relation to the handle end; the letter that follows this digit defines the specific
contact on that deck For example position 3H is located on the third deck from the
handle end, the contact is terminal H.
a.
Test.
(1) Tag and disconnect wiring to switch contacts.
(2) Set a multimeter to RX1 scale and test for contact continuity across terminals A-H and D-E on all decks when
switch is in LOCAL position. Test for contact continuity across terminals A-B and E-F on all decks when
switch is In the REMOTE position.
(3) Multimeter should indicate Infinity across all terminal pairs not specified for continuity in step (2), above.
(4) Rotation of handle should exhibit positive latching action in both the LOCAL and REMOTE positions.
b.
Remove. See Figure 4-68.
(1) Tag and disconnect wiring to switch (1) contacts
(2) Remove screw in center of handle and slide handle off shaft.
(3) Remove four screws from face of mounting plate on front of cabinet B door and remove switch as an
assembly.
4-178
