INSTALLATION INSTRUCTIONS
69-2807-01
S9240F2051 Modulating Integrated
Furnace Control
APPLICATION
The S9240F2051 Integrated Furnace Control (IFC) is
designed specifically to work with an Allied variable firing rate,
high efficiency furnace. It provides gas ignition, safety shutoff,
and variable speed fan control with multi-firing rate gas
heating and up to 2-stage electric cooling applications.
The S9240F2051 IFC is designed to work with:
• A Conventional thermostat (one or two stages) with or
without a non-communicating outdoor unit (heat pump or
A/C).
• An Allied communicating thermostat and non-
communicating outdoor unit (one or two stages).
• An Allied communicating thermostat and communicating
outdoor unit (one stage, multistage, or modulating).
NOTE: When configured in a communicating system,
the IFC is able to communicate alarms, demands
for heat/cool/dehumidification/etc., and other
information to other components in the system.
Refer to the documentation for complete details
including operating mode sequences.
FEATURES
The S9240F2051 provides the following features:
• Monitors a single stage or 2-stage conventional low
voltage thermostat for requests for heat, cool, or fan.
• Monitors an input provided for connection to a
thermostat with a dehumidification output.
• Provides three stage furnace input rate control when
operating with a conventional single stage thermostat.
• Provides 2-stage or modulating furnace input rate
control based on field selected option when operating
with a conventional 2-stage thermostat.
• Provides full modulating rate (between 40% and 100%
of furnace input) in response to an Allied
communicating thermostat.
• Manages ignition of a main burner flame up to 400,000
BTU per hour using a 120 Vac hot surface igniter.
• Monitors the appliance pressure, limit, and rollout
switches and generate control actions as programmed.
• Controls the 24 Vac Honeywell amplified gas/air gas
valve.
• Controls a 3-phase 120 Vac inducer motor (Fasco
Model 92B1 or other with identical voltage/frequency
curve) and blower assembly based on heat demand
and other parameters.
• Controls the Regal Beloit or Nidec ECM circulator
motor and blower based on defined appliance CFM
profiles
and/or a discharge air sensor signal.
• Controls single stage or 2-stage cooling equipment.
The outdoor unit is controlled directly by the 24 Vac
conventional thermostat inputs. The IFC manages the
circulator speed based on cool demand and other
parameters.
• Controls a 120 Vac humidifier output and a 120 Vac
EAC output. Optionally, controls a 24 Vac low voltage
humidifier.
• Operates with 120 Vac single phase, 60 Hz power
supply.
• Uses a 7-segment LED display to communicate error
code and status information. A single on board button
is provided to generate the desired information
display.
• Field selectable DIP switches to select field specific
control operating parameters such as type of
thermostat, delay timings, and fan operating
parameters.
• On-board jumpers that can be clipped to permanently
enable 2-stage cooling, heat pump compatibility,
dehumidification sequences, and define appliance
characteristics for field replacement purposes.
• Field Test Mode and Diagnostic Recall Mode to assist
the installation/service technician.
• Stores the 10 most recent error codes, which are
accessible by the service technician in Diagnostic
Recall Mode.
• Communications mode using an Allied communicating
thermostat.
• On-board relays (Y1 and Y2) to control a 2-stage
compressor when using the communications mode
with an Allied communicating thermostat.
