MD Helicopters 369-500, Maintenance Instructions Manual

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CSP-HMI-3
MD Helicopters, Inc
.
MAINTENANCE MANUAL
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Revision 11
96-48-00
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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
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1999 − 2016 by MD Helicopters, Inc.
Table 201. Float Lamp Assembly Troubleshooting (Cont)
Symptom Corrective Action Probable Trouble
Loose wire at terminal 1 or 2 or circuit
breaker switch CB140
Tighten wire connection.
Loose wire at terminal A1 or A2 of
relay K307
Tighten wire connection.
Loose wire L522B10 at terminal 1 of
lamp DS149
Tighten wire connection.
Loose wire L522G10N at terminal 2 of
lamp DS150 or ground terminal E12
Tighten wire connection.
Both float lamps flicker Loose wires at terminals indicated
above
Tighten wire connections as required.
One float lamp flickers Broken lamp filament, or loose wires
at terminals indicated above
Replace lamp or tighten wire
connections as required.
One or both lamps dim Loose wire at terminals indicated
above
Tighten wire connections as required.
3. Float Lamp Circuit Operation
(Ref. Figure 202) When switch S32 is set to
FLOAT LT, +28 Vdc passes across circuit
breaker switch CB140, to terminals A and X1
and through the solenoid to terminal X2 of
relay K307, through connector P/J113, to
switch S32, back through connectors P/J113 to
ground.
With relay K307 energized, +28 Vdc passes
from terminal A1 to the armature, to terminal
A2 of the relay, to terminal 1 of each of the
parallel connected lamps DS149 and DS150,
through their filaments to terminal 2, then to
ground at terminal E12.
Use of the remote solenoid relay K307 protects
the switch contacts from the high lamp current
output from the terminal board and assures
delivery of a maximum of current to the lamp
filaments.
CR37 prevents the relay solenoid from
developing a transient overvoltage developed
when switch S32 is opened.
4. Float Lamp Replacement
(Ref. Figure 201)
Consumable Materials
(Ref. Section 91 − 00 − 00)
Item Nomenclature
CM220 Naphtha aliphatic
CM408 Adhesive, silicone rubber
CM614 Sleeving, heat-shrink
(1). Verify lamp switch on pilot's collective
stick is set to OFF.
(2). Remove four fillips-head screws and
locknuts securing lamp retainer to lamp
housing.
(3). Strip adhesive seal from lamp joint, and
pull lamp out to gain access to lamp
terminal screws (Ref. Figure 203).
(4). Remove two lamp terminal screws to
disconnect wires.
(5). Before installing lamp, inspect interior
of lamp housing.
(a). Inspect fiberglass abrasion strip for
security of attachment.
(b). Inspect insulating sleeve
RNF100X1/2 (CM614) on shank of
cap screw for security of attachment.