21
SEQUENCE OF OPERATION
Cooling Mode
Energizing the “O” terminal energizes the unit reversing valve thus
placing the unit into cooling mode. The fan motor starts when the
“G” terminal is energized.
NOTE
: The fan motor will take 30 seconds to ramp up to
operating speed and will run at fan only rated air flow as long as
there is no call for compressor or heater operation.
When the thermostat calls for first stage cooling (Y1) the loop
pump or solenoid valve, if present, is energized and the first stage
of compressor capacity starts. The fan ramps up to first stage
cooling air flow in 30 seconds.
NOTE
:
Some options will have a built in delay therefore,
compressor operation is not immediate. See
Factory Installed
Options
section for more detail.
When the thermostat calls for second stage cooling (Y2), the
second stage (or full compressor capacity) is initiated. The fan
ramps up to full cooling air flow.
Once the thermostat is satisfied, the compressor shuts down and the
fan ramps down to either FAN ONLY mode or OFF over a span of
30 seconds.
NOTE
: A fault condition initiating a lockout will de--energize the
compressor irrespective of which stage is engaged.
Heating Mode
The first two stages of heating (Y1 & Y2) operate in the same
manner as cooling, but with the reversing valve de--energized. On a
call for auxiliary heat (W1), the fan ramps up to auxiliary heat air
flow immediately and the electric heater package is energized along
with the compressor.
As the thermostat is satisfied, the heaters will shut off as soon as
W1 is de--energized, and the compressors will remain on until the
thermostat stages are satisfied.
NOTE
: If the unit compressor locks out for any reason at this
time, the electric heaters will continue to function normally.
Once the thermostat is satisfied, the compressor shuts down and the
fan ramps down to either FAN ONLY mode or OFF over a span of
30 seconds.
If thermostat has two different output points one for Auxiliary heat
and a different one for Emergency heat the two outputs must be
terminated on W1 units equipped with one stage of Electric heat.
(See Fig. 23)
NOTE
: When using a 2--cool, 3--heat thermostat, both the W1 &
W2 on the Heat Pump and W2 & EM on the thermostat must be
connected together via a jumper. (See Fig. 23)
ELECTRONIC THERMOSTAT
INSTALLATION
Position the thermostat sub--base against the wall so that it is level
and the thermostat wires protrude through the middle of the
sub--base. Mark the position of the sub--base mounting holes and
drill holes with a 3/16--inch bit. Install supplied anchors and secure
base to the wall.
Thermostat wire must be 8--conductor, 18--AWG wire. Strip the
wires back 1/4--inch (longer strip lengths may cause shorts) and
insert the thermostat wires into the connector as shown in Fig. 23.
Tighten the screws to ensure secure connections. The thermostat
has the same type connectors, requiring the same wiring.
Refer to the thermostat Installation Instructions for detailed
installation and operation information.
NOTE
: When using a 2--cool, 3--heat thermostat, both the W1 &
W2 on the Heat Pump and W2 & EM on the thermostat must be
connected together via a jumper. (See Fig. 23)
THERMOSTAT
PACKAGED
HEAT PUMP
Y1
G
C
O
R
Y1
G
B
R
W2
C
O
E
B
W1
W2
Y2
Y2
A14135
Fig. 23 -- Thermostat Wiring
NOTE
:
Packaged heat pumps are equipped with detachable
thermostat connectors. These connectors are located in different
locations based on the blower motor that is installed in the unit.
-- For the EON motor, the three detachable thermostat connectors
are located on the ECM Interface Board. See Wiring Harness
Drawing on page 7, Fig. 4.
NOTE
:
Harness wiring can be loose, based on the options
installed for the unit. See the Wiring Harness drawing notes for
further details.
