Goodman ACS series Service Instructions Manual page 72

PRODUCT DESIGN
NORMAL SEQUENCE OF OPERATION
Goodman / Amana® Distinctions™ Brand Single-Stage
80% or 90% Furnaces
White-Rodgers 50A55 Integrated Ignition Control
P U
OWER P
1. 115 VAC power applied to furnace.
2. Integrated ignition control module performs internal
checks.
3. Integrated ignition control module LED will light.
4. Integrated ignition control monitors safety circuits con-
tinuously.
5. Furnace awaits call from thermostat.
N H S
ORMAL EATING EQUENCE
1. R and W thermostat contacts close, initiating a call for
heat.
2. Integrated control module performs safety circuit
checks.
3. The induced draft blower is energized causing pres-
sure switch contacts to close. Induced draft blower
remains energized for pre-purge period. Humidifier ter-
minals are energized with induced draft blower.
4. Ignitor warm up begins after pre-purge is completed.
The White-Rodgers 50A55 ignition control has a vari-
able ignitor warm up period between a 17-second maxi-
mum and a 5-second minimum.
5. Gas valve opens at end of ignitor warm up period, deliv-
ering gas to burners to establish flame.
6. The control checks for a signal from the flame sensor
within seven (4) seconds after the gas valve is ener-
gized. Gas will only continue to flow if a flame signal is
present.
7. Circulator blower is energized on heat speed following
a fixed thirty (30) second blower on delay. Electronic
air cleaner terminals are energized with circulator blower.
8. Furnace runs, integrated control module monitors safety
circuits continously.
9. R and W thermostat contacts open, allowing the gas
valve to cycle off.
10. Induced draft blower is de-energized following a fifteen
(15) -second post purge. Humidifier terminals are de-
energized.
11. Circulator blower is de-energized following a selectable
heat off delay period (90, 120, 150 or 180 seconds).
Electronic air cleaner terminals are de-energized.
12. Furnace awaits next call from thermostat.
The adjustable delay-off timing allows the installer to cus-
tomize the comfort level.
72
Cooling Mode
The normal operational sequence in cooling mode is as
follows:
1. R and Y thermostat contacts close, initiating a call for
cool.
2. Integrated control module performs safety circuit
checks.
3. Outdoor fan and compressor are energized.
4. Circulator blower is energized on cool speed following
a fixed five (5) second on delay. Electronic air cleaner
terminals are energized with circulator blower.
5. Furnace circulator blower and outdoor cooling unit run,
integrated control module monitors safety circuits con-
tinuously.
6. R and Y thermostat contacts open, completing the call
for cool.
7. Outdoor fan and compressor are de-energized.
8. Circulator blower is de-energized following a fixed forty
five (45) second cool off delay period. Electronic air
cleaner terminals are de-energized.
9. Furnace awaits next call from thermostat.
Fan Only Mode
The normal operational sequence in fan only mode is as
follows:
1. R and G thermostat contacts close, initiating a call for
fan.
2. Integrated control module performs safety circuit
checks.
3. Circulator blower is energized on heat speed. Elec-
tronic air cleaner terminals are energized.
4. Circulator blower runs, integrated control module moni-
tors safety circuits continuously.
5. R and G thermostat contacts open, completing the call
for fan.
6. Circulator blower is de-energized. Electronic air cleaner
terminals are de-energized.
7. Furnace awaits next call from thermostat.