MD Helicopters 369-500, Maintenance Instructions Manual

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CSP-HMI-3
MD Helicopters, Inc
.
MAINTENANCE MANUAL
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Page 202
TR16-001
96-10-00
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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
©
1999 − 2016 by MD Helicopters, Inc.
3. Generator Control Unit (GCU)
The GCU maintains constant generator output
voltage under varying speeds and load
conditions. Internal circuitry provides voltage
regulation, overvoltage protection, reverse
current protection direct load meter drive to
the starter/generator. Overcurrent sensing of
the starter/generator protects the battery and
starter/generator from harming each other in a
reverse current situation. Internal circuitry
provides a ground for the GEN OUT indicator
when generator failure occurs.
A. Generator Control Unit (GCU)
Replacement
(Ref. Figure 201)
NOTE:
When installing the generator control
unit, adjust the current limit switch to
match the installed starter/generator (Ref.
Figure 202).
(1). Ensure all electrical power is OFF.
(2). Disconnect electrical connector and
remove attaching hardware and GCU.
(3). Install replacement GCU and attach
electrical connector.
(4). Perform adjustment of installed GCU.
B. Adjustment of Installed Generator
Control Unit (GCU)
To accomplish a full charge, the 17 amp hr - 20
cell battery requires a higher regulated voltage
than the 13 amp hr - 19 cell battery. The GCU
must be adjusted to supply the required
voltage for the 17 amp hr - 20 cell battery. Any
time the GCU is adjusted for use with the 17
amp hr - 20 cell battery, the decal must be
attached to the GCU cover.
Special Tools
(Ref. Section 91 − 00 − 00)
Item Nomenclature
ST1009 Voltmeter
Overheating of the battery
can occur and fire and/or ex­
plosion can result if the proper voltage
settings are not used with the appro­
priate battery installed.
EFFECTIVITY: 369E 384 & SUBS
369FF 076 & SUBS
500N 001 & SUBS
600N 003 & SUBS.
SCREW
WASHER
GENERATOR
CONTROL UNIT
G96-1017A
Figure 201. Generator Control Unit (GCU) Removal/Installation
WARNING