Goodman Mfg MVC95 - Manual (Page 43)

43
COMFORTNET™ SYSTEM
demand and transmits the demand along with a fan request
to the indoor unit. The indoor unit then sends the demand
to the ECM motor. The table below lists the various
ComfortNet™ systems, the operating mode, and airflow
demand source.
System
System Operating
Mode
Airflow Demand Source
Cooling Air Conditioner
Heating Furnace
Continuous Fan Thermostat
Cooling Heat Pump
Heat Pump Heating
Only
Heat Pump
Auxiliary Heating Furnace
Continuous Fan Thermostat
Cooling Furnace
Heating Furnace
Continuous Fan Thermostat
Furnace + Non-
Comm 1stg Air
Conditioner
Air Conditioner +
Furnace
Heat Pump +
Furnace
For example, assume the system is an air conditioner
matched with a furnace. With a call for low stage cooling,
the air conditioner will calculate the system’s low stage
cooling airflow demand. The air conditioner will then send a
fan request along with the low stage cooling airflow demand
to the furnace. Once received, the furnace will send the low
stage cooling airflow demand to the ECM motor. The ECM
motor then delivers the low stage cooling airflow. See the
applicable ComfortNet™ air conditioner or heat pump
installation manual for the airflow delivered during cooling or
heat pump heating.
In continuous fan mode, the CTK01AA thermostat provides
the airflow demand. The thermostat may be configured for
a low, medium, or high continuous fan speed. The low,
medium, and high fan speeds correspond to 25%, 50%,
and 75%, respectively, of the furnaces’ maximum airflow
capability. During continuous fan operation, the thermostat
sends a fan request along with the continuous fan demand
to the furnace. The furnace, in turn, sends the demand to
the ECM motor. The ECM motor delivers the requested
continuous fan airflow.
F
OSSIL
F
UEL
A
PPLICATIONS
This furnace can be used in conjunction with a CT™ compatible
heat pump in a fossil fuel application. A fossil fuel application
refers to a combined gas furnace and heat pump installation which
uses an outdoor temperature sensor to determine the most cost
efficient means of heating (heat pump or gas furnace). When
used with the CTK01AA thermostat, the furnace/heat pump
system is automically configured as a fossil fuel system. The
balance point temperature may be adjusted via the CTK01AA
thermostat advanced user menus (see CTK01AA instructions
for additional information).
CTK01AA W
IRING
NOTE: Refer to Electrical Connections for 115 volt line connections
to the furnace.
NOTE: A removable plug connector is provided with the control to
make thermostat wire connections. This plug may be removed,
wire connections made to the plug, and replaced. It is strongly
recommended that multiple wires into a single terminal be twisted
together prior to inserting into the plug connector. Failure to do so
may result in intermittent operation.
Typical 18 AWG thermostat wire may be used to wire the system
components. One hundred (100) feet is the maximum length of
wire between indoor unit and outdoor unit, or between indoor unit
and thermostat. Wire runs over (100) feet require larger gauge
wire.
F
OUR
-W
IRE
I
NDOOR AND
O
UTDOOR
W
IRING
Typical ComfortNet™ wiring will consist of four wires between the
indoor unit and outdoor unit and between the indoor unit and ther-
mostat. The required wires are: (a) data lines, 1 and 2; (b) thermo-
stat “R” (24 VAC hot) and “C” (24 VAC common).
1 2 R C
1 2 R C
CTK01AA
Thermostat
CT™ Compatible Furnace
Integrated Control Module
CT™ Compatible AC/HP
Integrated Control Module
1 2 R C
System Wiring using Four-Wires
T
WO
-W
IRE
O
UTDOOR
, F
OUR
-W
IRE
I
NDOOR
W
IRING
Two wires can be utilized between the indoor and outdoor units.
For this wiring scheme, only the data lines, 1 and 2, are needed
between the indoor and outdoor units. A 40VA, 208/230 VAC to
24VAC transformer must be installed in the outdoor unit to provide
24VAC power to the outdoor unit’s electronic control. The trans-
former is included with the CTK01AA kit. See kit instructions for
mounting and wiring instructions. Four wires are required between
the indoor unit and thermostat.
NOTE: Use of the CTK01AA transformer is recommended if
installing a dual fuel/fossil fuel system. Failure to use the
transformer in the outdoor unit could result in over loading of the
furnace transformer.