Intertek ACVC96 Service Instructions Manual page 36

INSTALLATION CONSIDERATIONS
Single-Stage Thermostat Application
A single-stage thermostat with only one heating stage may
be used to control this furnace. The application of a single-
stage thermostat does not offer "true" thermostat-driven two-
stage operation, but provides a timed transition from low to
high fire. The furnace will run on low stage for a fixed period
of time before stepping up to high stage to satisfy the
thermostat's call for heat. The delay period prior to stepping
up can be set at either a fixed 5 minute time delay or a load
based variable time between 1 and 12 minutes (AUTO mode).
If the AUTOmode is selected, the control averages the cycle
times of the previous three cycles and uses the average to
determine the time to transition from low stage to high stage.
To use a single-stage thermostat, turn off power to the fur-
nace, move the thermostat selection DIP switch to the OFF
position. Set the desired transition time by setting the tran-
sition delay DIP switch to the desired ON/OFF position. Turn
power back on. Select preferences on S1 #3 and #4 DIP
switches.
24 Volt Dehumidistat Wiring (Not needed if a
communicating thermostat is used)
The optional usage of a dehumidistat allows the furnace's
circulator blower to operate at a slightly lower speed (85%
of desired speed) during a combined thermostat call for cool-
ing and dehumidistat call for dehumidification. This can be
done through an independent dehumidistat or through a
thermostat's DEHUM terminal (if available). This lower blower
speed enhances dehumidification of the conditioned air as it
passes through the AC coil. For proper function, a dehumi-
distat applied to this furnace must operate on 24 VAC and
utilize a switch which opens on humidity rise.
To install/connect a dehumidistat:
1. Turn OFF power to furnace.
2. Secure the dehumidistat neutral wire (typically the white
lead) to the terminal marked "DEHUM" on the furnace
integrated control module.
3. Secure the dehumidistat hot wire (typically the black
lead) to the terminal marked "R" on the furnace integrated
control module.
4. Secure the dehumidistat ground wire (typically the green
lead) to the ground screw on the furnace junction box.
NOTE: Ground wire may not be present on all dehumi-
distats.
5. Turn ON power to furnace.
To enable the dehumidify function on the integrated control
module, set the dehumidification ENABLE dipswitch from
OFF to ON.
Once the switch is set, the dehumidify function is enabled
during a combination call for cooling (T-Stat) and dehumidi-
fication (DEHUM-Stat).
For a furnace equpped with aPCBKF101 or PCBKF102 con-
trol board, select preferences on S5 #9 DIP switch.
36
For a furnace equipped with a PCBKF103 or PCBKF104
control board, select preferences on S5 #1 DIP switch.
Fossil Fuel Applications
This function is automatically configured and controlled when
using a communicating thermostat.
Furnaces can be used in conjunction with a heat pump in a
fossil fuel application. A fossil fuel application is where an
outdoor temperature sensor determines the most cost effi-
cient means of heating (heat pump, gas furnace, or both).
A heat pump thermostat with two stages of heat is required
to properly use the single-stage furnace with a heat pump.
A heat pump thermostat with three stages of heat is re-
quired to properly use the two-stage furnace with a heat
pump. Refer to dual fuel, AFE-18-60A installation manual
(IO-627) for additional wiring instructions.
CONTINUOUS FAN OPERATION
Continuous fan speed is selectable from a communicating
thermostat or by DIP switches when using a conventional
thermostat. ----------------------------
CIRCULATOR BLOWER SPEED ADJUSTMENT
HIGH VOLTAGE
D ALL
ISCONNECT POWER BEFOR CHANGING SPEED TAPS.
M
ULTIPLE POWER SOURCES MAY BE PRESENT.
SO MAY CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH.
Blower set up is automatically configured in a fully commu-
nicating system. Adjustments can also be made at the
communicating thermostat. Set up blower speeds with DIP
switches when using a conventional thermostat.
This furnace is equipped with a multi-speed circulator blower.
This blower provides ease in adjusting blower speeds. The
heating blower speed is shipped set at "B", and the cooling
blower speed is set at "D". These blower speeds should be
adjusted by the installer to match the installation require-
ments so as to provide the correct heating temperature rise
and correct cooling CFM.
Use the dual 7-segment LED display adjacent to the
dipswitches to obtain the approximate airflow quantity. The
airflow quantity is displayed as a number on the display,
rounded to the nearest 100 CFM. The display alternates
airflow delivery indication and the operating mode indica-
tion.
COOLING CFM
Example: The airflow being delivered is 1225 CFM. The
display indicates 12. If the airflow being delivered is 1275,
the display indicates 13.
1. Determine the tonnage of the cooling system installed
with the furnace. If the cooling capacity is in BTU/hr
divide it by 12,000 to convert capacity to TONs.
WARNING
F
AILURE TO DO