ARMY TM 9-6115-604-12
NAVY NAVFAC P 8 633-12
4-94.
CROSS CURRENT ADJUST RHEOSTAT R105. CROSS CURRENT ADJUST rheostat R105 controls the load
sharing capabilities of the generator set voltage regulators when in a parallel condition.
a.
Test
(1) Remove wire from terminal 3 of CROSS CURRENT ADJUST rheostat R105 (9, Figure 2-3).
(2) Rotate knob fully counterclockwise.
(3) Using a multimeter on RX1 scale, check for continuity across terminals 1 and 2. The reading should be 1
ohm.
(4) While observing the multimeter, slowly rotate knob in a clockwise direction. Meter resistance Indication
should decrease smoothly, with no erratic jumps at any point in travel.
(5) When knob (wiper arm terminal 2) is In the fully clockwise stop position, total resistance indication shall be
continuity.
(6) Connect wire removed from terminal 3.
(7) Replace CROSS CURRENT ADJUST rheostat R105 if It does not meet the specifications above.
b.
Remove.
(1) Tag and disconnect wiring to CROSS CURRENT ADJUST rheostat R105 (9, Figure 2-3).
(2) Remove knob.
(3) Loosen and remove locking nut at front of bracket and rheostat from the rear.
c. Install.
(1) Install CROSS CURRENT ADJUST rheostat R105 (9, Figure 2-3) to the bracket Position CROSS CURRENT
ADJUST rheostat (9) so that the arrow will be in the 9 o'clock position once the knob is attached and the
shaft is rotated fully counterclockwise.
(2) Attach the knob.
(3) Connect wires and discard tags.
4-95.
FREQUENCY SEL SW S118. FREQUENCY SEL SW S118 Is used to select 50 or 60 hertz operation of the
generator set.
a.
Remove.
(1) Tag and disconnect wires.
(2) Loosen screw In center of FREQUENCY SEL SW S118 (8, Figure 2-3) knob and slide knob off shaft.
(3) Remove mounting screws at front of panel and slide switch out from the rear.
b.
Test
(1) Tag and disconnect all wiring to switch contacts.
(2) Set FREQUENCY SEL SW S118 to 60 Hz position. Set multimeter to RX1 scale and check resistance
across contacts 22 and 21, and 22 and 23, and across contacts 26 and 25, and 26 and 27 on deck 2.
Compare results with figure 4-64.
(3) Set FREQUENCY SEL SW S118 to 50 Hz position. Set multimeter to RX1 scale and check resistance
across contacts 22 and 21, and 22 and 23, and across contacts 26 and 25, and 26 and 27 on deck 3, as
above. Compare results with figure 4-64.
c.
Install.
(1) Install FREQUENCY SEL SW S118 (8, Figure 2-3) in panel from rear, and attach with mounting screws.
NOTE
Verify position of STOP screws on rear of switch to limit switch rotation to two positions.
4-161
