Cooling Cycle; Fan Mode; Description Of Components; Maintenance - Nordyne *SA Upfl ow / Horizontal Installation Instructions Manual

The Indoor blower motor is de-energized after a blower
off delay as selected by the movable jumper.

Cooling Cycle

1. The thermostat calls for cooling by energizing the Y
terminal with 24VAC.
2. The control energizes the blower in the cooling speed
and sends 24VAC to the contactor in the condensing
unit.
3. When the thermostat removes the call for cooling,
the contactor in the outdoor condensing unit is de-
energized and the control continues to run the fan for
a period of 60 seconds.

Fan Mode

• When the thermostat energizes the G terminal for
continuous fan (without calling for heat or cooling), the
indoor fan is energized on the selected FAN speed.
• If a call for cooling occurs during continuous fan, the
blower will switch over to the selected COOL speed.
• If the W terminal receives a call for heat during
continuous fan, the blower will de energize.
• A call for fan is ignored while in lockout.

DESCRIPTION OF COMPONENTS

The descriptions below are various functional components
that affect the operation and shutting down of this furnace.
Some of these components and their locations are shown in
Figure 20 (page 34). If any component of the furnace must
be replaced, use only factory authorized replacement parts
specifi ed in the Replacement Parts List provided online.
Blower Limit Switch: Prevents operation when blower
is not operational.
Flame Sensor: Verifi es when a fl ame has carried over
from the igniter to the opposite end burner. If no fl ame is
detected, the furnace will shut down within 4 seconds.
Flame Roll-Out Switch: Verifi es that the burner fl ames
are drawn into the heat exchanger tubes. If the burner
fl ames are not properly drawn into the heat exchanger, the
fl ame roll-out switch will close the gas valve and initiate
the shutdown cycle.
Gas Valve: Controls the fl ow of gas to the burners. When
the gas valve is energized it automatically opens and
regulates the gas pressure in the manifold.
Inducer Assembly: Vents products of combustion to
the outside.
Pressure Switch: Verifi es that the inducer is drawing
the combustion gases through the heat exchanger. The
pressure switch prevents furnace operation with excessive
fl ue blockage or improper inducer operation.
Supply Air Limit Switch: Prevents the air temperature
leaving the furnace from exceeding the maximum allowable
outlet air temperature.

MAINTENANCE

Proper maintenance is most important to achieve the best
performance from a furnace. Follow these instructions for
years of safe, trouble free operation.
WARNING:
ELECTRICAL SHOCK, FIRE OR EXPLOSION
HAZARD
Failure to follow safety warnings exactly could
result in serious injury or property damage.
Improper servicing could result in dangerous
operation, serious injury, death or property
damage.
• Before servicing, disconnect all electrical
power to furnace.
• When servicing controls, label all wires prior
to disconnecting. Reconnect wires correctly.
• Verify proper operation after servicing."
AVERTISSEMENT:
RISQUE DE CHOC ÉLECTRIQUE, D'INCENDIE
OU D'EXPLOSION
Le non-respect des avertissements de sécurité
pourrait entraîner un fonctionnement dangereux
de l'appareil, des blessures graves, la mort ou des
dommages matériels.
Un entretein incorrect pourrait entraîner un
fonctionnement dangereux de l'appareil, des
blessures graves, la mort ou des dommages
matériels
• Couper toute alimentation électrique au
générateur d'air chaud avant de prodéder
aux travaux d'entretein.
• Au moment de l'entretien des commandes,
étiquetez tous les fi ls avant de les débrancher.
S'assurer de les raccorder correctement.
• S'assurer que l'appareil fonctionne
adéquatement aprés l'entretien.
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