Installation guide

LineVoltageWiring
Connectionsforlinevoltagearemadeintheunitcontrolbox
area.RefertowiringdiagramlocatedontheBurnerAccess
panel.Foraccess,removetheburneraccesspanel.
1.Runthehighvoltage(L1,L2)andgroundleadsintothe
controlbox.
2. Connectgroundleadtochassisgroundconnection.
3. ConnectL1 to pressurelug connection11 of the
compressorcontactor.
4. ConnectL2 to pressurelug connection23 of the
compressorcontactor.
Thermostat/ Low Voltage Wiring
Location of the thermostat has an important effect on home
comfort. FOLLOW THE THERMOSTAT INSTRUCTION
MANUAL FOR CORRECT LOCATION, MOUNTING, AND
WIRING.
A two-stage thermostat is required for proper operation.
Thermostat must have the following terminals: "R",
"W/W1 ", "Y1 ", "Y2", and "G'. Some electronic thermostats
use low voltage from the unit for power for temperature
display and programming. These electronic thermostats
will have a "C" terminal. The outdoor unit has color-coded
wires for easy connection. Using wire nuts, follow figure 9
for proper connections:
PLEASE NOTE: While a high stage heat pigtail is provided
('W2", BLK), the approved thermostat will not respond to
this connection. Make sure that dip switch 3 on the ignition
control board is in the "OFF" position. The ignition control
board is in the control box assembly, and the wiring diagram
label will show the correct dip switch position. With dip
switch 3 in the "OFF" position, gas heating will always be on
low stage for the first 10 minutes. If after 10 minutes of
continuous low stage gas heat operation the thermostat is
still not satisfied, the ignition control will step up to high
stage gas heat for the remainder of the thermostat call.
FIGURE 9 I Thermostat Connections
I
Unit ControJ Power
Thermostat and subbase
The violet-colored pigtail connects to the dehumidification
feature of this unit. The dehumidification feature reduces
cooling airflow by 20% to increase latent heat removal when
the humidity is high. The reduced airflow occurs when there
is the presence of 24V to the violet-colored pigtail.
Approved thermostats that have the "DH" terminal are
available through your distributor
THERMOSTAT HEAT ANTICIPATOR
Some thermostats have an adjustable heat anticipator. The
heat anticipator prevents temperature overshoot in heating
mode. If the heat doesn't turn off until the set point
temperature on the thermostat is exceeded, then the
anticipator setting is too low. If the heat turns off before the
thermostat reaches the set point temperature on the
thermostat, then the anticipator setting is too high. Follow
the thermostat instruction manual for proper adjustment of
the heat anticipator.
Final Electrical Check
1. Make a final wiring check to be sure system is correctly
wired. Inspect field installed wiring and the routing to
ensure that rubbing or chafing due to vibration will not
occur.
NOTE: Wiring MUST be installed so it is protected from
possible mechanical damage.
BALANCE POINT TEMPERATURES
The dual fuel models require a dual fuel thermostat for
proper operation. A dual fuel thermostat allows a balance
point temperature to be programmed into the thermostat
and has an outdoor temperature sensor that must be
installed outside. Follow the thermostat installation
instructions for proper location of outdoor sensor. The dual
fuel unit operates either in heat pump mode or gas heat
mode, but NEVER both modes at the same time.
There are 2 different balance point temperatures to
consider when programming the thermostat: Economic
and Load.
Economic Balance Point Temperature
The economic balance point temperature is the outdoor
temperature where the utility cost of running in heat pump
mode is the same as running in gas heat mode. If the
outdoor temperature is above the economic balance point
temperature, then the heat pump mode will be less costly. If
the outdoor temperature is below the economic balance
point temperature, then the gas heat mode will be less
costly. The economic balance point temperature is affected
by electrical utility cost, gas utility cost, and model size.
Knowing the utility cost of electricity and gas, the economic
balance point temperature can be determined using Figure
10.
Figure 10 - Economic Balance Point Temperature Chart
Economic Balance Point Temperature (°F)
Cost PDX424 PDX430 PDX436 PDX442 PDX448 PDX460
Ratio* 040 060 080 080 100 100
0.075 0 0 2 0 1 2
0.100 20 19 20 20 18 18
0.125 42 32 34 34 31 29
0.1375 50 40 38 38 40 38
0.150 57 48 43 42 46 44
* CostRatiois the electricalcost,in$ perkilowatt-hour,dividedbythegas
cost,in$ per therm.