MD Helicopters 369-500, Maintenance Instructions Manual

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CSP-HMI-3
MD Helicopters, Inc
.
MAINTENANCE MANUAL
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[ HMI − 3 Book TOC ]
[ Chapter 96 TOC ]
Page 210
Revision 7
96-30-00
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.
17. Switch Control Panel
The edgelighted switch control panel is a
removable assembly on the electrical console.
Individually-removable generator, utility
power and start pump switches are installed
on the panel. Additional switches may be
installed for control of optional equipment.
Control functions are apparent from adjacent
legends. The UTILITY PWR and START
PUMP switch/circuit breakers snap to the OFF
position if the circuit is overloaded. The plastic
panel assembly contains integral light
elements mounted on a separable light circuit
board that is attached to the plastic panel with
screws. The switch control panel assembly also
supports the overvoltage relay and wiring
terminal block TB11.
18. Switch Panel and Switch Replacement
(1). Check that all electrical power is OFF .
(2). Remove five screws that secure switch
control panel to the console. Carefully
lift the panel as far as possible to gain
access to the underside.
(3). Remove four screws, nuts and washers
that attach the power selector switch;
remove switch and insulator. Note bond
jumper attachment location.
(4). Remove four screws, washers and
plastic panel.
(5). Remove hex nut and washer. Then
remove switch far enough to disconnect
wiring from switch.
(6). Place insulator under power selector
switch before installing switch, and
reconnect bond jumper. Locate replace­
ment switch in position, reconnect
wiring and install attaching hardware.
(7). Reinstall panel and check operation of
replacement switch.
19. Lights Control Panel
The edgelighted lights control panel is
removable from the electrical console. Compo­
nents on the panel are individually replace­
able. Control functions are apparent from
adjacent legends. The ANTI-COLLISION light
switch is a switch-circuit breaker. The plastic
panel contains integral circuitry and lamps.
When instrument and panel lights SW PANEL
OFF-BRT potentiometer is rotated clockwise,
voltage is increased to a switching regulator in
the dimmer control unit, which applies
increased voltage to all panel lamps on the
instrument panel and control panels of the
electrical controls console. (For indicator lights
dimmer assembly information, refer to Section
95-00.)
20. Lights Control Panel − Switches or
Potentiometer Replacement
(Ref. Figure 208)
(1). Check that all electrical power is OFF.
(2). Loosen setscrew and remove knob from
lights control panel.
(3). Remove four screws, washers and
edge-lighted plastic panel.
(4). Release four turnlock fasteners that
secure the lights control panel to the
console. Carefully lift the panel as far
as possible to gain access to the under­
side. Disconnect wiring and tag-identi­
fy as necessary to aid reinstallation.
(5). Remove hex nut and lockwasher that
secures switch or potentiometer to
mounting plate; remove applicable unit.
NOTE:
Check that the no-turn tang washer of
the potentiometer will not contact the plas­
tic panel; trim if necessary.
(6). Install replacement switch or poten­
tiometer with keyway or no-turn tang
aligned, and install hex nut with
lockwasher.
(7). Connect electrical wiring and remove
identifying tags, if used.
(8). Reinstall panel and check operation of
replacement switch.
21. Inspection
(1). Check that all electrical power is OFF.
Inspect connectors, wire harness, switches,
circuit breakers, bus bars and attaching
hardware for security and evidence of damage.