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I-UNIT COMPONENTS
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic discharge can affect
electronic components. Take precautions
to neutralize electrostatic charge by
touching your hand and tools to metal
prior to handling the control.
ML196DFE unit components are shown in FIGURE 1. The
combustion air inducer, gas valve and burners can be ac
-
cessed by removing the outer access panel. The blower
and control box can be accessed by removing the blower
access panel.
A-Control Box Components (FIGURE 2)
Unit transformer (T1) and integrated ignition control (A92
are located in the control box. In addition, a door interlock
switch (S51) is located in the control box.
DOOR INTERLOCK
SWITCH (S51)
INTEGRATED IGNITION
CONTROL
(A92)
TRANSFORMER
(T1)
Control Box
CIRCUIT
BREAKER
(CB8)
FIGURE 2
1. Transformer (T1)
A transformer located in the control box provides power
to the low voltage section of the unit. The transformers on
all models are rated at 40VA with a 120V primary and 24V
secondary.
2. Door Interlock Switch (S51)
A door interlock switch rated 14A at 120VAC is located
on the control box. The switch is wired in series with line
voltage. When the blower door is removed the unit will
shut down.
3. Circuit Breaker (CB8)
A 24V circuit breaker is also located in the control box. The
switch provides overcurrent protection to the transformer
(T1). The breaker is rated at 3A at 32V.
If the current exceeds this limit the breaker will trip and all
unit operation will shutdown. The breaker can be manually
reset by pressing the button on the face.
4. Integrated Ignition Control (A92)
103217-03 & 107163-01
WARNING
Shock hazard.
Disconnect power before servicing. Control is not
field repairable. If control is inoperable, simply
replace entire control.
Can cause injury or death. Unsafe operation will
result if repair is attempted.
The hot surface ignition control system consisting of an
integrated control (FIGURE 3 or FIGURE 5) with control
terminal designations in tables TABLE 1, TABLE 2, TABLE
3, sensor and ignitor (FIGURE 6).
The integrated control and ignitor work in combination to
ensure furnace ignition and ignitor durability. The integrat
-
ed control, controls all major furnace operations. The inte
-
grated control also features a RED LED for troubleshoot
-
ing and two accessory terminals rated at (1) one amp. The
nitride ignitor is made from a non-porous, high strength
proprietary ceramic material that provides long life and
trouble free maintenance.
TABLE 1
4-Pin Terminal Designation
PIN #
FUNCTION
1
Combustion Air Inducer Line
2
Ignitor Line
3
Combustion Air Inducer Neutral
4
Ignitor Neutral
TABLE 2
12-Pin Terminal Designations
PIN #
FUNCTION
1
High Limit Output
2
IFC 103217-03 Not Used
IFC 107163-01 Flame Sense
3
24V Line
4
Not Used
5
Rollout Switch Out
6
24V Neutral
7
High Limit Input
8
Ground
9
Gas Valve Common
10
Pressure Switch In
11
Rollout Switch In
12
Gas Valve Out
