STEMME S12, Maintenance Manual

Page: 207 / 290

DOCUMENT NUMBER:
L500-912.820 ISSUE JUL 20, 2016
AMENDMENT: 00
DATE: --
CHAPTER- PAGE 7-49
MAINTENANCE MANUAL STEMME S12
7.7 ELECTRICAL SYSTEM
Description: See section »3.7« and »Maintenance Manual (Line Maintenance) for
ROTAX Engine Type 914 Series« (Annex E).
7.7.1 GENERAL
• Check wiring of entire electric system (observe section »5.2.4«). Specially check
cable routing for sufficient supports, for chafing in the area of penetrations of cable
(e. g. firewall) and for signs of overheating.
• Check condition of CB’s, replace if required.
• Check any electrical device and all switches for proper installation, tight fit and proper
cable connections.
• Check electrical switches in the cockpit for intended function. Perform this check during
an engine test run, refer to section »7.4.1.17«.
REGULATOR VOLTAGE
Average: 13.75 V
Maximum: 14.20 V
The values indicated are valid for the engine bus with internal generator and main bus with ex-
ternal, belt driven, alternator.
7.7.2 BATTERIES
• Check condition of avionic battery (housing, contacts, state of charge) and starter battery.
• Check mounting assy. of main battery in forward tail cone.
Voltage drop of a charged main battery
as new at approximately 15° C during starter operation: 2 V
For maintenance on the batteries, please refer to the Manufacturer’s Instructions (Annex A).
WARNING
If battery energy is not required for test purposes during any maintenance on the electrical system,
the negative connection to the battery should be disconnected.
To remove the battery, disconnect the negative cable first. To install the battery, connect the
positive cable first, then connect the negative.
The engine must never be started from the auxiliary, external electrical power receptacle
(if installed) without the battery installed.