Airplane Factory SLING LSA
Pilot Operating Handbook
Page | 9-11
Date of Issue: 07 July 2014
Revision : 1.3
ELECTRICAL SYSTEM
The engine is equipped with two 3-phase ac generators (alternators). One
alternator (Alternator A) supplies power to the EMS/ ECU and the other
(Alternator B) is available to the aircraft systems / to charge the battery. The
output of the charge system is connected to the main bus via a circuit breaker
(labeled FUSEBOX) located on the instrument panel
The main battery is connected to the main bus (and thus the charge system) via
the Master switch. The back-up battery supply to the EMS/ECU is sourced
directly from the battery, and routed to the EMS/ECU via an activation switch
(labeled ECU BKUP) located on the instrument panel.
Until the engine reaches idling speed the EMS / ECU requires a 12 V supply from
the aircraft system (i.e. the main battery). When Alternator A fails the EMS /
ECU is automatically switched over to Alternator B. Note that in this event
Alternator B output is not (or only partially) available to the aircraft systems and
that no (or reduced) main battery charging can occur. Subsequent failure of
Alternator B will result in engine stoppage. In that event power (EMS / ECU
back-up voltage) can be supplied to the EMS / ECU system via the aircraft
system (main battery) voltage (i.e. EMS / ECU battery back-up switch is switched
on) and the engine restarted.
The engine can run (provided EMS / ECU back-up switch in on) after an
Alternator A and Alternator B failure (i.e. both failed), until the battery voltage is
low (approximately 30 minutes if all ancillary equipment is switched off and
provided that the battery is fully charged at time of (the last remaining)
alternator failure). The engine will cease running due to fuel starvation (due to
the ECU/EMS/electrical pump(s) stopping) when the battery is depleted.
CAUTION
The EMS / ECU battery back-up switch should not be in the ON position
during flight, except when both Alternator A and Alternator B have failed.