XLT XD-9006A (GAS Oven Version – C, AVI Hood Version – C) - Manual (Page 9)

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GAS OVEN THEORY OF OPERATION
CAP - The Capacitor is physically mounted inside the Control Box but wired to the externally
mounted Oven Fan Motor (M1). The Oven Fan Motor (M1) is a Permanent Split Capacitor (PSC)
motor. PSC means a capacitor motor in which the starting capacitor and the auxiliary winding re-
main in the circuit for both starting and running.
CB - Circuit Breakers are used to protect electrical components. The current value is printed on
the front of all breakers. If a CB is tripped, eliminate the cause and press the front to reset.
CC - The Conveyor Control is supplied 24 VDC by the Power Supply (PS) via a Circuit Breaker
(CB3 & CB4, optional) to Terminals 4 & 5. The belt time is displayed, and is user-adjusted by
pressing and holding the up or down arrow button switches. See the Specification Sheet for mini-
mum and maximum belt times. The motor speed is calculated based on the time that is entered.
This time is translated to a RPM on the motor shaft depending on the size of the oven, the diameter
of the sprocket, and the gear ratio of the gearbox. Once the motor is running, hall sensor inputs are
fed back into the driver to determine the speed the motor is currently running at. This input goes
into a PID algorithm to adjust the Pulse Width Modulation (PWM) output to control the speed to
match the target speed that was calculated first. This PWM is adjusting the average voltage that
the motor phases are seeing. As the average voltage goes up, the motor will speed up. As the av-
erage voltage drops, the motor speed will also drop. The maximum speed is based on a continuous
18-24V being supplied to the motor. The phasing of the controller is dependent on the hall sensor
signals that are being returned. The controller reads the hall sensor position and from there knows
which phase of the motor receives the 18-24V signal, which phase of the motor is the return and
which phase of the motor is left open. As the motor spins, the hall sensors change, which dictate
which phases are energized.
FS/SI - The Flame Sensor/Spark Igniter consists of a copper-clad metal mounting plate, a ground
electrode, and two additional electrodes encapsulated in ceramic insulators. One of the insulated
electrodes has a 1/4” male spade welded to it while the other insulated electrode has a 3/16” male
spade welded to it. The rod with the 1/4” spade connects to the Spark Terminal on the Ignition
Control (IC) via a spark wire. The end of this rod is positioned near the ground electrode in such a
way so as to create a small gap. When the high-voltage signal from the IC reaches the gap, it is
forced to jump the gap resulting in a spark.
Flame has the unique ability to rectify AC voltage and current into DC voltage and current.
The electrode with the 3/16” spade is positioned in such a way so that the electrode is inside the
flame envelope. A wire connects this electrode to Terminal S1 on the IC. A green ground wire is
attached to the copper-clad mounting plate, and connected to chassis ground inside the control box.
When flame is present, a DC current flow is detected by the IC. The amount of current flow is de-
termined by the position of the flame sensor and the size of the flame. The minimum current flow
to maintain operation is .7 µA.