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I-UNIT COMPONENTS
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic discharge can affect elec
tronic components. Take precautions
to neutralize electrostatic charge by
touching your hand and tools to metal
prior to handling the control.
EL196UHE 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 blow
er 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.
FIGURE 2
EL196UHE Control Box
Integrated Control
Door Interlock
Switch
Transformer
Circuit Breaker
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 volt
age. 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 ex
ceeds 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 re
place entire control.
Can cause injury or death. Unsafe operation will re
sult if repair is attempted.
The hot surface ignition control system consisting of an in
tegrated control (figure 3 or 5 with control terminal desig
nations in tables 1, 2 and 3), sensor and ignitor (figure 6).
The integrated control and ignitor work in combination to
ensure furnace ignition and ignitor durability. The inte
grated control, controls all major furnace operations. The
integrated control also features a RED LED for trouble
shooting and two accessory terminals rated at (1) one
amp. See table 4 for troubleshooting diagnostic codes.
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