Unit Components - Haier GE NF80XV Series Service Manual

Unit Components

NF80XV unit components are shown in Figure 1. The gas
valve, combustion air inducer and burners can be accessed
by removing the access panel. Electrical components are
in the control box (Figure 2) found in the blower section.
NF80XV units are factory equipped with a bottom return air
panel in place. The panel is designed to be field removed
as required for bottom air return. Markings are provided for
side return air and may be cut out in the field.
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic discharge can affect electronic components.
Take precautions during furnace installation and service
to protect the furnace's electronic controls. Precautions
will help to avoid control exposure to electrostatic
discharge by putting the furnace, the control and the
technician at the same electrostatic potential. Neutralize
electrostatic charge by touching hand and all tools on
an unpainted unit surface, such as the gas valve or
blower deck, before performing any service procedure.
Control Box
Control Transformer (T1)
A transformer located in the control box provides power
tothe low voltage section of the unit. Transformers on
allmodels are rated 40VA with a 120V primary and a 24V
secondary.
Door Interlock Switch (S51)
A door interlock switch rated 14A at 125VAC is wired in
series with line voltage. When the inner blower access
panel is removed the unit will shut down.
CONTROL BOX
Transformer
Circuit Breaker
Figure 2.
31-5000734 Rev. 0
Interlock Switch
®
SureLight Integrated Control
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 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. See Figure 3.
CIRCUIT BREAKER CB8
PRESS TO RESET
Shock hazard.
Disconnect
Integrated control is not field repairable. If
control is inoperable, simply replace entire
control. Can cause injury or death. Unsafe
operation will resul if repair is attempted.
Integrated Control (A92)
Units are equipped with a two-stage, variable speed
integrated control. The system consists of a ignition /
blower control (Figure 4 and Figure 5) with control pin
designations in Table 1, Table 2 and Table 3 and ignitor
(Figure 13). The control and ignitor work in combination to
ensure furnace ignition and ignitor durability. The control
provides gas ignition, safety checks and indoor blower
control with two-stage gas heating.
The furnace combustion air inducer, gas valve and indoor
blower are controlled in response to various system inputs
such as thermostat signal, pressure and limit switch signal
and flame signal. The control features a seven-segment
LED display, indicating furnace status (including indoor
blower) and error codes. The LED flashes in single digits.
For example, under LIMIT CODE, an "E" followed by "2"
followed by "5" followed by "0", the limit switch circuit
is open. The control also has two unpowered (dry) 1/4"
contacts for a humidifier and a 120 volt accessory terminal.
Both rated at (1) one amp each.
Electronic Ignition
At the beginning of the heat cycle the integrated control
monitors the first stage and second stage combustion air
inducer prove switch. The control will not begin the heating
cycle if the first stage prove switch is closed (by-passed).
Likewise the integrated control will not begin the second
stage heating cycle if the second stage prove switch is
closed, and will remain in first stage heat. However, if the
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Figure 3.
WARNING
power before servicing.