TM 5-6115-590-12
factory, shut down power plant and disconnect and remove analyzer.
(3) Fuel control assembly acceleration limiter valve cracking pressure adjustment. If the fuel control assembly is
replaced, or if the acceleration limiter valve cracking pressure is not within specified limits, check and adjust as follows:
(a) Disconnect fuel line at atomizer and install the portable 0-100 psi pressure gauge.
(b) Disconnect control air line at acceleration limiter valve tee.
(c) With fuel supplied to fuel control assembly at 15 psig, move master switch (S1) (fig. 2-11, sheet 1 of 2) on
power plant instrument panel assembly to START position and motor engine.
CAUTION
Do not exceed starter motor duty cycle.
(d) While motoring unit, check cracking pressure. Cracking pressure should be 44 + 1 psig. To adjust, hold
acceleration limiter valve adjustment screw (fig. 4-16) on fuel control assembly and loosen locknut. Adjust screw
position using screwdriver and wrench assembly (special tools). To increase cracking pressure turn acceleration limiter
valve adjustment screw clockwise. To decrease pressure, turn adjustment screw counterclockwise.
CAUTION
Do not turn adjusting screw more than three full turns in either direction. -
(e) When satisfactory cracking pressure is attained, tighten locknut.
(f) Reconnect control air pressure line to acceleration limiter valve. Remove gauge from tee on fuel control
assembly, reconnect fuel line, disconnect and remove gas turbine engine analyzer.
(4) Fuel control assembly governor speed setting. If fuel control assembly is replaced or if engine speed at full
load or at no load is not as specified, check and adjust as follows.
(a) Connect gas turbine engine analyzer to power unit as described in paragraph 4-14b. Use tach-generator
rpm gauge (fig. 4-14) on analyzer panel to check engine speed.
(b) Start engine (fig. 2-11) and accelerate to no load governed speed. Operate at this speed for
approximately two minutes to stabilize operation.
(c) Apply full load to engine. To apply load, open compressed air outlet as described in fig. 2-18 and operate
cooled air system as described in fig. 2-15.
(d) With engine operating at full load, tach-generator rpm gauge (fig. 4-14) should read 4150 + 10 rpm (equal
to an engine speed of 40,700 + 100 rpm).
(e) If tach-generator rpm gauge does not read 4150 + 10 rpm use screwdriver and wrench assembly (special
tools) to adjust full load governed speed.
(f) Hold governor adjustment screw (fig. 4-16) on fuel control assembly and loosen locknut. Turn governor
adjustment screw clockwise to increase full load governed speed, and counterclockwise to decrease full load governed
speed. When adjustment is satisfactory, tighten locknut.
CAUTION
Do not turn screw more than three turns in either direction.
(g) Close compressed air outlet as described in fig. 2-18, shut off cooled air system as described in figure
2-15, and return the engine to no load governed speed.
(h) Tach-generator rpm gauge (figure 4-14) should read 4242 rpm (maximum) (equal to an engine speed of
41,600 rpm).
(i) If tach-generator rpm gauge does not read 4242 rpm (maximum), use screwdriver and wrench assembly
(special tools) to adjust no load governed speed setting.
(j) Hold governor adjustment screw (figure 4-16) on fuel control assembly and loosen locknut. Turn
adjustment screw clockwise to increase no load governed turn adjustment screw counterclockwise to decrease no load
governed speed.
(k) When adjustment is satisfactory, tighten locknut, disconnect and remove gas turbine engine analyzer.
(5) Air pressure regulator. If air pressure regulator is replaced or if controlling air pressure is not as specified, check
and adjust as follows.
(a) Disconnect outlet air pressure line from air pressure regulator and connect a line between the air pressure
regulator outlet port and the AIR in connection (fig. 4-14) on gas turbine engine analyzer.
(b) Start and accelerate engine to no load governed speed. Read air pressure regulator outlet pressure on
AIR gauge on analyzer panel.
(c) Air pressure regulator outlet pressure shall be 19.0 to 20.0 psig.
(d) If pressure is not as specified, shut down engine. Loosen locknut on end of air pressure regulator and turn
adjustment screw clockwise to increase outlet pressure. Tighten locknut
(e) Repeat check procedure until satisfactory adjustment is made. Disconnect and remove gas turbine engine
analyzer.
(6) Centrifugal Multi-Speed Switch Setting. If the centrifugal multi-speed switch is replaced or if
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