MD Helicopters 369-500, Maintenance Instructions Manual

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CSP-HMI-3
MD Helicopters, Inc
.
MAINTENANCE MANUAL
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[ Chapter 95 TOC ]
95-30-00
Page 501
Revision 7
The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright
©
1999 − 2016 by MD Helicopters, Inc.
POWER TRAIN INSTRUMENTS
ADJUSTMENT/TEST
1. Power Train Instruments Adjustment/Test
(369D/E/FF − 500N)
2. Tachometer Generator Test
(Ref. Figure 501)
(1). Connect tachometer generator to test
harness and equipment shown.
(2). Mount tachometer generator on test
stand with case grounded.
(3). Start tachometer test stand. Set speed
control to zero rpm. Turn strobe light
switch ON.
(4). Connect tachometer generator to test
set-up for 20 ohm load test (test No. 1).
(5). Increase tachometer generator speed to
1000 rpm. Check phase-to-phase
voltage; TP1 to TP2, TP1 to TP3 and
TP2 to TP3. Voltage should be 3.0 - 4.0
Vac for each measurement.
(6). Reduce tachometer generator speed to
zero, disconnect 20 ohm test setup and
connect 40 ohm load test setup (test No.
2).
(7). Increase tachometer generator speed to
3600 rpm. Check phase-to-phase
voltage; TP1 to TP2, TP1 to TP3 and
TP2 to TP3. Voltage should be 17.5 -
18.5 Vac for each measurement.
(8). Increase tachometer generator speed to
4200 rpm. Check phase-to-phase
voltage; TP1 to TP2, TP1 to TP3 and
TP2 to TP3. Voltage should be 20.0 -
22.0 Vac for each measurement.
(9). Reduce tachometer generator speed to
zero, disconnect 40 ohm test setup and
prepare for open circuit test (test No. 3).
(10). Increase tachometer generator speed to
3600 rpm. Check phase voltage; pin A
to ground, pin B to ground and pin A to
pin B. Voltage should be 25.0 - 31.0 Vac
for each measurement.
(11). Replace generator if output voltage
does not meet test requirements.
3. TOT Indicating System Calibration
Consumable Materials
(Ref. Section 91 − 00 − 00)
Item Nomenclature
CM408 Adhesive, silicone rubber
Special Tools
(Ref. Section 91 − 00 − 00)
Item Nomenclature
ST1011 Turbine temperature indicating system
test set
Following procedure is to be performed at
periodic intervals specified (Ref. Chap. 05), and
when required due to system malfunction or
suspected error in indications.
(1). For Slim-Line instrument panels and
L/H command T-Panels, remove left
instrument panel fairing.
(2). Check that engine thermocouple lead
connections are tight and there is no
corrosion on terminals.
Do not connect test equipment
to TOT indicating system until
indicator is disconnected.
(3). Disconnect resistor board TB9 from
indicator terminal lugs and remove
indicator from instrument panel.
NOTE:
Adjustable resistor R4 adjusts TOT cir­
cuit resistance to calibrate TOT indicating
system. Early resistors with sliding contacts
are to be replaced, as necessary, with cur­
rently supplied resistors having rotating
contacts. Modification of TOT resistor board
will provide a finer degree of adjustment by
adding an additional resistor in parallel
(Ref. Sec. 95-00-00, Instrument Repair).
(4). Using tester (ST1011), or an equivalent
precision ohmmeter, check total circuit
resistance through resistor R4 and
complete thermocouple system. Resis­
tance must be 8.0
±
0.05 ohms.
CAUTION