MD Helicopters 369D - Revision 7

CSP-HMI-3MD Helicopters, Inc.
MAINTENANCE MANUAL
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96-00-00
Page 203
Revision 11
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.
Before removing or installing components of electrical system, ensure that electrical power is OFF.
If units are not immediately replaced, ensure all electrical connectors are suitably capped and
stowed and all loose cable ends are properly insulated and stowed to prevent possibility of
shorting. Serious injury or death could result from voltages present in electrical systems.
Before troubleshooting electrical system, ensure proper configuration of helicopter. Refer to Section
96-10-00 to verify current helicopter charging system components.
Table 201. Troubleshooting Electrical System
Symptom Probable Trouble Corrective Action
Battery fails to energize electrical
circuits
Defective BATTERY−OFF−EXT
PWR switch
Replace switch.
Defective battery relay Replace battery relay.
Battery discharged Install serviceable battery.
K200 Battery Hi Temp relay Replace Battery Hi Temp relay.
Discharged battery
Charging rate incorrectly set Adjust voltage regulator or *GCU.
Battery idle to long Install serviceable battery.
Excessive corrosion on battery
terminals
Exposure to water or corrosive
fluids
Clean terminals; coat with
non−corrosive grease.
Battery overheats and/or
discharges smoke
Charging rate to high Adjust voltage regulator or *GCU.
Loose battery terminal links, straps
or screws
Repair battery as necessary.
Damaged or defective battery Repair or replace battery.
Starter−generator fails to function
when START switch pressed
Circuit breaker out Reset circuit breaker.
Start relay defective Replace start relay.
Battery relay defective Replace battery relay.
APU relay defective Replace APU relay.
Discharged battery Install serviceable battery.
APU, reverse polarity, diode open Replace diode.
Starter−generator defective Replace starter−generator.
START switch or wiring defective Replace switch, or repair defective
wiring.
*Defective fwd line contactor *Replace fwd line contactor.
WARNING