DOC AIRBUS | AMM A320FDISTRIBUTION - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. Description
The ignition for each engine is carried out by means of one or both ignition exciters which transform(s) the 115 V - 400 Hz power supply into high voltage pulsating current.
The high voltage flows through the ignition lead (shielded and ventilated) and delivers to the spark igniter the power required to initiate the fuel/ air mixture combustion by a series of sparks.
The ignition for each engine is carried out by means of one or both ignition exciters which transform(s) the 115 V - 400 Hz power supply into high voltage pulsating current.
The high voltage flows through the ignition lead (shielded and ventilated) and delivers to the spark igniter the power required to initiate the fuel/ air mixture combustion by a series of sparks.
A. Ignition Leads
An ignition lead transmits electrical energy from an ignition exciter to a spark igniter. Each lead consists of a 0.28 in. (7 mm) diameter silicone insulated cable containing a No. 14 AWG nickel plated copper stranded conductor. The 0.28 in. (7 mm) cable is housed within a flexible conduit which features a nickel plated copper inner braid, a nickel-iron convoluted conduit, and a nickel outer braid.
Fan discharge air is introduced into an enlarged diameter portion of each ignition lead conduit for cooling of the silicone insulated cable and igniter connection.
An ignition lead transmits electrical energy from an ignition exciter to a spark igniter. Each lead consists of a 0.28 in. (7 mm) diameter silicone insulated cable containing a No. 14 AWG nickel plated copper stranded conductor. The 0.28 in. (7 mm) cable is housed within a flexible conduit which features a nickel plated copper inner braid, a nickel-iron convoluted conduit, and a nickel outer braid.
Ignition LeadFan discharge air is introduced into an enlarged diameter portion of each ignition lead conduit for cooling of the silicone insulated cable and igniter connection.
B. Spark Igniter
(1) General
There are 2 spark igniters in combustion case bosses at the 4 and 8 o'clock position, aft looking forward, on the combustion case assembly. The tip of the spark igniters extends through ferrules in the outer liner into the combustion chamber. Each spark igniter is connected by an ignition lead to an ignition exciter.
When charged by a high voltage from the ignition exciter, the spark igniter provides an arc to ignite the fuel being injected into the combustion chamber by the fuel nozzle assemblies.
There are 2 spark igniters in combustion case bosses at the 4 and 8 o'clock position, aft looking forward, on the combustion case assembly. The tip of the spark igniters extends through ferrules in the outer liner into the combustion chamber. Each spark igniter is connected by an ignition lead to an ignition exciter.
When charged by a high voltage from the ignition exciter, the spark igniter provides an arc to ignite the fuel being injected into the combustion chamber by the fuel nozzle assemblies.
(2) Operation
When the ignition exciter discharges the high voltage pulses through the ignition lead to the spark igniter, electric arc pulses occur between the center electrode and the outer electrode, and an ionized discharge occurs. The hot ion discharge ignites the fuel injected by the fuel nozzles. The electrical pulse discharges continue until electrical supply to the ignition exciter is stopped.
When the ignition exciter discharges the high voltage pulses through the ignition lead to the spark igniter, electric arc pulses occur between the center electrode and the outer electrode, and an ionized discharge occurs. The hot ion discharge ignites the fuel injected by the fuel nozzles. The electrical pulse discharges continue until electrical supply to the ignition exciter is stopped.