TM-6115-465-34
NAVFAC P-8-625-34
T.O. 35C2-3-446-2
TM 06858B/06859D-34
(10) Slowly increase the tester shaft speed while moni-
(1) Screw the tachometer fitting onto the test stand.
toring the VOM. When Element No. 2 trips. the reading will
go from O volts to 24 volts. Trip speed for Element No. 2
(2) Attach the connector and cable to J37 of the speed
(50/60 Hz) is 590 to 610 RPM. Trip speed for Element No.
switch.
2 (400 Hz) is 825 to 850 RPM.
(3) Connect 24 volts dc to pins E. G and 1 with the
(11) Continue increasing shaft speed while monitoring
polarity indicated in the test circuit.
pin H for voltage. It should be at 24 volts. dropping to 0
volts when the third element trips. Trip speed for Element
(4) Using the VOM test for the conditions listed be-
low:
No. 3 is 1200 to 1250 RPM.
Element No. 1:
(12) After Element No. 3 has tripped. connect the VOM
between pins F and J to check for continuity. Continuity
should exist after Element No. 3 has tripped.
Pins A&B . . . . . . . . . . . . . . . . . . . . . . . . . . . continuity
Pins A&C . . . . . . . . . . . . . . . . . . . . . . . . . . . open circuit
(13) Slowly decrease shaft speed while monitoring pin
D with the VOM for voltage. There should be 24 volts pre-
Element No. 2:
sent. dropping to 0 volts when Element No. 2 resets. "Reset
Speed" for Element No. 2. should be no more than 100
Pin D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0 volts dc to ground
RPM below the trip speed noted in Step ( 10).
Element No. 3:
(14) Continue decreasing shaft speed while measuring
Pins F&J . . . . . . . . . . . . . . . . . . . . . . . . . . . . . open circuit
for continuity between pins A and C with the VOM. Contin-
Pin H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 volts dc to ground
uity should exist between these two pins until Element No. 1
resets. then an open circuit should exist. Reset speed for
(5) Connect the VOM to read continuity between pins
Element No. 1 should be no more than 100 RPM below the
A and B.
trip speed noted in step (6).
(6) Slowly bring up shaft speed of the tester. At 290
(15) Decrease shaft speed to O RPM. Monitor pm H for
to 310 rpm Element No. 1 should trip causing an open cir-
voltage with the VOM. Element No. 3 should still remain in
cuit to appear between pins A and B.
the tripped condition. resulting in 0 volts on pin H. and con-
tinuity between pins F and J.
(7) After Element I has tripped, check with the VOM
for continuity between pins A and C.
(16) Depress and release the reset switch, S1. on the
speed switch. Pin H should not read 24 volts on the VOM.
(8) Proper tripping of Element No. I is indicated by
meeting the conditions of steps (4). (6) and (7).
f.
Assembly. Assemble speed switch in reverse order
of disassembly.
(9) Connect the VOM to read voltage on pin D with
Installation. Refer to Operator and Organizational
respect to ground.
Maintenance Manual and install speed switch in reverse order
of removal.
Change 4
3-19
