TM 5-6115-434-12
(a)
Connect gas turbine engine analyzer (fig. 3-5) to power unit as described in paragraph 3-8b above.
Control engine speed with valve (fig. 3-3) on analyzer panel.
(b)
Use tach-generator rpm gage (fig. 34) on analyzer panel to read engine speed.
(c)
Start and operate engine as described in paragraph 3-8d above checking for switch actuation of
centrifugal multi-speed switch.
(d)
If 35 percent switch requires adjustment, remove cover plate from centrifugal multi-speed switch (fig.
3-15) and adjust position of top screw (screw farthest from switch receptacle). Replace cover plate and recheck switch
setting at least twice.
Note
If 35 percent switch setting is changed, the settings of 95 percent speed switch and overspeed
(110 percent) switch must be checked.
(e)
If 95 percent speed switch requires adjustment, remove cover plate from centrifugal multi-speed
switch and adjust position of middle screw. Replace cover plate and recheck switch setting at least twice.
(f)
To check actuation of overspeed (110 percent) switch, use screw driver and wrench assembly
(special tools); loosen locknut and turn fuel control assembly governor adjusting screw two full turns clockwise to
increase governor setting. Start engine and use needle valve (fig. 34) on analyzer panel to slowly accelerate to
overspeed condition. Overspeed (110 percent) switch should actuate to shut down engine at 4512 25 tach-generator
rpm reading (equal to an engine speed of 44, 250 250 rpm).
(g)
If overspeed (110 percent) switch required adjustment, remove cover plate and adjust position of
bottom screw (screw nearest to receptacle). Replace cover plate and recheck switch setting at least twice.
(h)
When all switch settings are satisfactory, reset fuel control assembly governor screw to original
position.
(i)
Recheck fuel control assembly governor setting as described in paragraph 88e (4), above.
(j)
When centrifugal multi-speed switch checks and fuel control assembly governor setting checks are
satisfactory, disconnect and remove gas turbine engine analyzer.
Section V. FIELD EXPEDIENT REPAIRS
3-9. General
Organizational maintenance troubles may occur while the power unit is operating in the field where supplies and repair
parts are not available and normal corrective action cannot be performed. When this condition exists, the following
expedient repairs may be used in emergencies, upon the decision of the unit commander. Equipment to be repaired
must be removed from operation as soon as possible and properly repaired before being placed in operation again.
3-10. Repairs
a.
Start Relay (K1) failure (fig. 3-20).
(1)
If start relay (K1) fails, remove K1 and battery transfer contactor (K93) as described in paragraphs 3-62a
and 3-62d. Replace K1 relay with K33 relay.
(2)
If start relay (K1) fails to energize, utilize a number 2 wire and jumper across terminals Al and A2. After
gas turbine engine lights off and reaches approximately 35 percent governed speed, jumper may be removed.
Warning
Use an insulated number 2 wire to jumper across terminals A1 and A2 on the start relay (K1).
High voltage may cause serious injury or death to personnel .
b.
Door Interlock Switch Failure (S4) (S27) (S28) (533) (S34). Disconnect harness from door interlock switch and
place jumper across harness terminals. Fasten door securely open. When run is completed, remove jumper and door
fastenings.
c.
Relay Failure (K11, K12, K19, K20, K27, K43A, K43B). All the above named relays are interchangeable and any
one may be substituted
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