TM 5-6115-434-12
Caution
Do not permit exhaust gas temperature to exceed 682 °C (1260°F).
(i)
If controlling temperature is not 671 °C to 682°C (1240°to 1260°F) shut down power unit and adjust
thermostat as follows. (fig. 3-9).
(j)
Remove thermostat as described in removal procedure, paragraph 3-26a. Remove thermostat valve
assembly (fig. 3-9) and shims from thermostat body.
(k)
Measure total thickness of shims (fig. 8-9) with micrometer. Add or remove shims as required. To
decrease temperature setting, increase shim stack thickness. To increase temperature setting decrease shim stack
thickness. A change of 0.001 inch in shim stack thickness will change controlling temperature by approximately 300F.
Install corrected thickness of shims and fitting.
(I)
Reinstall thermostat as described in installation procedure paragraph 3-26b.
(m)
Recheck controlling temperature at least twice. When controlling temperature is satisfactory,
reconnect load control thermostat line to load control valve (fig. 3-24). Disconnect and remove gas turbine engine
analyzer.
(2)
Load control thermostat. If load control thermostat (fig. 8-24) is replaced, or if controlling temperature is
not as specified, check and adjust as follows.
(a)
Connect gas turbine engine analyzer to power unit as described in paragraph 3-8b above.
(b)
Load engine as described in steps e(l)(e), (f) and (g) above.
(c)
Observe engine exhaust gas temperature on analyzer. The load control thermostat should modulate
the load control valve to control exhaust gas temperature at 552 °C to 579°C (1025°F to 1075°F). If control temperature
is not 552°C to 579°C (1025°F to 1075°F), shutdown power unit and adjust thermostat as follows.
(d)
Remove thermostat as described in removal procedure (para 3-78a).
(e)
Remove thermostat valve assembly (fig. 8-24) and shims from thermostat body. TM 5-6115-424-12
(f)
Measure total thickness of shims with micrometer. To decrease temperature setting, increase shim
stack thickness. To increase temperature setting, decrease shim stack thickness. A change of 0.001 inch in shim stack
thickness will change cracking temperature by approximately 30 °F. Add or remove shims as required. Install corrected
thickness of shims and fitting.
(g)
Reinstall thermostat as described in paragraph 3-73b.
(h)
Recheck controlling temperature at lease twice.
(i)
When controlling temperature is satisfactory, shut down power unit and disconnect and remove
analyzer.
(3)
Fuel control assembly acceleration limiter valve cracking pressure adjustment. If the fuel control
assembly (fig. 3-8) is replaced, or if the acceleration limiter valve cracking pressure is not within specified limits. Check
and adjust as follows.
(a)
Disconnect connector (fig. 1-5) from oil pressure sequencing switch (fig. 1-5) to prevent lightoff, with
pressure at the limiter valve.
(b)
Disconnect fuel line from tee (fig. 3-5) at fuel control assembly outlet point and install a 0 to 100 psig
pressure gage.
(c)
Disconnect control air line (fig. 3-5) at acceleration limiter valve tee (fig. 3-5).
(d)
With fuel supplied to fuel control assembly at 15 psig, move master switch (S1) (fig. 2-22) on power
unit instrument panel assembly to START position and motor engine.
Caution
Do not exceed starter motor duty cycle.
(e)
While motoring unit, check cracking pressure. Cracking pressure should be 44 1 psig. To adjust
hold acceleration limiter valve adjustment screw (fig. 3-5) 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 (fig. 3-5) clockwise. To decrease pressure, turn acceleration limiter valve adjustment screw (fig.
86) counterclockwise.
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