Cessna 208B - Ignition System

CESSNA SECTION 7
MODEL 2088 (675 SHP) AIRPLANE AND SYSTEMS DESCRIPTION
IGNITION SYSTEM
The ignition system consists of two igniters, an ignition exciter, two
high-tension leads, an ignition monitor light, an ignition switch, and a
starter switch. Engine ignition is provided by two igniters in the engine
combustion chamber. The igniters are energized by the ignition exciter
mounted on the engine mount on the right side of the engine
compartment.
Electricil energy from the ignicon exciter is transmked
through two high-tension leads to the igniters in the engine. The an~tion
system is normally energized only duriing engine start.-
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Ignition is controlled by an ignition switch and a starter switch located
on the left sidewall switch and circuit breaker panel. The ignition switch
has two positions, ON and NORMAL. The NORMAL position of the
switch arms the ignition system so that ignition will be obtained when
the starter switch is placed in the START position. The NORMAL
position is used during all ground starts an during air starts with starter
assist. The ON position of the switch provides continuous ignition
regardless of the position of the starter switch. This position is used for
air starts without starter assist, for operation on water-covered runways,
during flight in heavy precipitation, during inadvertent icing encounters
until the inertial separator has been in bypass for 5 minutes, and when
near fuel exhaustion as indicated by illumination of the RESERVOIR
FUEL LOW annunciator.
The main function of the starter switch is control of the starter for
rotating the gas generator portion of the engine during starting.
However, it also provides ignition during starting. For purposes of this
discussion, only the ignition functions of the switch are described. For
other functions of the starter switch, refer to paragraph titled Starting
System, in this section. The starter switch has three positions, OFF,
START, and MOTOR. The OFF position shuts off the ignition system
and is the normal position at all times except during engine start or
engine clearing. The START position energizes the engine ignition
system provided the ignition switch is in the NORMAL position. After
the engine has started during a ground or air start, the starter switch
must be manually positioned to OFF for generator operation.
A green annunciator, located on the annunciator panel, is labeled
IGNITION ON, and will illuminate when electrical power is being
applied to the igniters. The ignition system is protected by a ""pull-off'
type circuit breaker, labeled IGN, on the lefl sidewall switch and circuit
breaker panel.
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U.S. 7-57