GMES96-U Installation Manual

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• Igniter warm up begins after 15 second pre-purge
expires.
• Gas valve opens at the end of igniter warm up
period, delivering gas to burners and establishing
flame.
• Integrated control module monitors flame presence.
Gas valve will remain open only if flame is detected.
• Circulator blower is energized on high heat speed
following a fixed five second blower on delay.
Electronic air cleaner terminals are energized with
circulator blower.
• Furnace operates; integrated control module
monitors safety circuits continuously.
• R and W thermostat contacts open, completing the
call for heat.
• Gas valve closes, extinguishing flame.
• Induced draft blower is de-energized following a thirty
second post purge.
• HUM terminal is de-energized.
• Circulator blower continues running for the selected
heat off delay period. Factory set at 150 seconds.
If required this can be changed in the field.
• EAC terminal is de-energized
• Furnace awaits next call from thermostat.
COOLING MODE
The normal operational sequence in cooling mode is as follows:
• R,Y and G thermostat contacts close, initiating a
call for cool.
• Integrated control module performs safety circuit
checks.
• Outdoor fan and compressor are energized.
• Circulator blower is energized on the cool speed.
Following a fixed 6 second delay. Other timing
available is 45 seconds. Jumper settings on the
integrated control board is B for 45 seconds delay.
• EAC terminal is energized.
• Furnace circulator blower and outdoor cooling unit
run their appropriate speeds, integrated control
module monitors safety circuits continuously.
• R,Y and G thermostat contacts open, completing the
call for cool.
• Outdoor fan and compressor are de-energized.
• Circulator blower continues running during a cool
off delay period of 45 seconds. EAC terminals are
denergized.
• Furnace awaits next call from thermostat.
FAN ONLY MODE
The normal operational sequence in fan only mode is as follows:
• R and G thermostat contacts close, initiating a call
for fan.
• Integrated control module performs safety circuit
checks.
• Circulator blower is energized on heat speed.
• EAC terminal is energized.
BLOWER SPEED ADJUSTMENT
To adjust the circulator blower speed, proceed as follows:
1. Turn OFF power to the furnace.
2. Select the heating and cooling blower speeds that
match the installation requirements from the airflow
table 10 in the Specification Sheet.
3. Relocate desired motor leads to the circulator blower
heat and cool speed terminals on the integrated control
module. (Terminals are identified as HEAT and COOL).
If heating and cooling blower speeds are the same, a
jumper wire must be used between the heat and cool
terminals.
4. Connect all unused blower motor leads to the “PARK”
terminals on the integrated control module. Any leads
not connected to the “PARK” terminals must be taped.
5. Turn ON power to furnace.
6. Verify proper temperature rise as outlined in the
Temperature Rise section of Startup Procedure and
Adjustment.
In general lower heating speeds will: reduce electrical consump-
tion, lower operating sound levels of the blower, and increase
the outlet air temperature delivered to the home. The speeds
available allow the blower performance to be optimized for the
particular homeowner’s needs.
BLOWER HEAT OFF DELAY TIMINGS
NOTE: Items in this section refer to the air circulator blower
fan, NOT to the induced draft blower. The induced draft
blower timing sequence is not adjustable.
The integrated control module on all models provides a select-
able heat off delay function. The delay is factory shipped at 150
seconds but may be changed to suit the installation require-
ments and/or homeowner preference. Other timings available
are 90, 120 and 180 seconds. Heat cycle jumper settings on
the integrated control board are A, B, and D respectively.
N ORMAL S EQUENCE OF O PERATION
POWER UP
The normal power up sequence is as follows:
• 115 VAC power applied to furnace.
• Integrated control module performs internal checks.
• LED will flash once at power up then remain on.
• Integrated control module monitors safety circuits
continuously.
• Furnace awaits call from thermostat.
HEATING MODE
The normal operational sequence in heating mode is as follows:
• R and W thermostat contacts close, initiating a call
for heat.
• Integrated control module performs safety circuit
checks.
• Induced draft blower is energized for 30 second pre-
purge period causing pressure switch contacts to
close.