508096-01
Issue 2037
Page
6
of 3
1
Unit Components
unit components are shown in Figure
1. The gas valve, combustion air inducer and
burners can be accessed by removing the upper
access panel. Electrical components are in the control
box (Figure 2)
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.
CAUTION
Control Box Components (Figure 2)
Unit transformer (T1) and integrated ignition control
(A92) are located in the control box. In addition, a door
interlockswitch (S51) is located in the control box.
DOOR INTERLOCK
SWITCH (S51)
INTEGRATED IGNITION
CONTROL
(A92)
TRANSFORMER
(T1)
CIRCUIT
BREAKER
(CB8)
Figure 2. Control Box
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.
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.
NOTE:
The door interlock switch is a safety switch. Do not
by-pass or jumper switch.
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.
Integrated Ignition Control
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.
WARNING
The hot surface ignition control system consisting of
an integrated control (Figure 3 with control terminal
designations in Table 1 through Table 3), sensor and
ignitor (Figure 6). The integrated control and ignitor work
in combination to ensure furnace ignition and ignitor
durability. The integrated control, controls all major furnace
operations. The integrated control also features a RED
LED for troubleshooting and two accessory terminals rated
at (1) one amp. See Table 4 or Table 5 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.
Pin #
Function
1
Combustion Air Inducer Line
2
Ignitor Line
3
Combustion Air Inducer Neutral
4
Ignitor Neutral
Table 1.
4-Pin Terminal Designations
Pin #
Function
1
High Limit Output
2
Not Used
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
Table 2.
12-Pin Terminal Designations
