High Voltage Gas System - Idc Overview - Taylor C832 Service Manual

High Voltage Gas System - IDC Overview

Ignition Detection Control
(International)
The International grill models contain an Ignition
Detection Control (IDC) which is responsible for the
ignition and monitoring of the gas burner system.
The Fenwal IDC operates with a single trial ignition
sequence. The IDC board has four functions.
S
Turning blower on/off
S
Opens gas solenoid
S
Creates a spark
S
Provides lockout safety features
System Overview
Call for Heat
When a call for heat is received from the Motor
Control Board 24 Volts are sent to TH/W. The IDC
will then check for normally open contacts at the
pressure switch. The blower is then turned on and
the control checks the pressure switch to ensure it is
closed, and the pre­purge of the burner begins. Next
the gas solenoids are energized and the IDC starts
its single trial ignition.
Ignition (Single Ignition)
When flame is detected during the ignition the IDC
stops sending voltage to the electrode. The blower
and gas solenoid remain energized. The IDC
monitors the 24 MCB input, pressure switch position
(Closed) and the presence of flame in the burner
(Flame Sense). When the call for heat is satisfied
(TH/W will receive a low signal from MCB) the gas
solenoid closes, the IDC monitors the loss of flame
sense and the blower is de­energized.
130612
Controls and Systems
IDC Fault Codes
The Fenwal IDC is equipped with system fault
detection. The fault modes are then expressed
through the IDC's LED. The following section will
cover the failures and their correlating LED
sequences. The LED will flash on for a ¼ of a
second and off for a ¼ of a second. The pause
between fault codes is 3 seconds.
Internal Control Failure (LED stays on)
This occurs when the IDC has an internal
component failure. The fault can be reset by cycling
the power of the grill. If the IDC continues to display
the fault after cycling the power the IDC will have to
be replaced.
Air Flow Fault (LED Flashes 1 time)
1. During the ignition sequence the IDC monitors
the blower air flow by monitoring the of the
pressure switch (pressure switch must be in
closed position). If the grill is calling for heat
and the pressure switch is closed for 30
seconds without the blower being energized,
the IDC will go into an air flow fault. The control
will remain in this lockout and the blower will be
off.
2. If the pressure switch stays open for 30
seconds after the blower is energized a fault
will be displayed. The blower will remain on
waiting for the pressure switch to close. When
pressure builds and close the switch, the IDC
will begin its normal ignition trial. If pressure
from the blower does not build the IDC will
remain in this fault mode.
3. If the pressure switch opens during a heat cycle
the gas valve will be de­energized and the
blower will remain on. If the pressure switch
does not close with 30 seconds a fault will be
displayed.
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McDonald's Intelligap Grills