Nordyne Two Stage R-410A Split System User's Information/Installation Instructions page 9

When constant 24 VAC (R) wire) is not present
in the outdoor unit, use one of the spare wires
in the thermostat cable to bring power to the
module. Connect the other end of the spare wire
to R at the indoor unit or thermostat.
Thermostat Demand Wiring — The Comfort
TM
Alert module requires a thermostat demand
signal to operate properly. The thermostat
demand signal input, labeled Y on the module,
should always be connected to the compressor
contactor coil so that when the coil is energized,
the demand signal input is 24 VAC when the coil
is not energized, the demand signal input should
be less than 0.5 VAC.
NOTE: Factory installed modules have differ-
ent thermostat demand signal wiring. Follow
manufacturer's wiring instructions when replac-
ing module.
NOTE: After the thermostat demand signal is
connected, verify that 24 VAC across Y and C
when demand is present.
Cooling — Gradually lower the thermostat
temperature setpoint below the actual room
temperature and observe that the outdoor unit
and indoor blower energize. Feel the air being
circulated by the indoor blower and verify that
it is cooler than ambient temperature. Listen
for any unusual noises. If present, locate and
determine the source of the noise and correct
as necessary.
Heating — If provided with heating equipment,
lower the thermostat setpoint temperature to the
lowest obtainable setting and set the thermostat
function switch to HEATING. The outdoor unit
should stop running. The indoor blower will go
off after the preprogrammed delay. Increase
the setpoint temperature of the thermostat to
the maximum setting. Verify that the heating
equipment has been energized (i.e., fossil fuel
burner operating, etc.) and that the indoor blower
energizes after a short period of time. Feel the
air being circulated by the indoor blower and
verify that it is warmer than ambient temperature.
Listen for any unusual noises. If present, locate
and determine the source of the noise and cor-
rect as necessary.
NOTE: Other sources for heating (i.e.: electric
furnace, fossil fuel furnace, air handler with
electric heat options, etc.) that interface with
the heat pump should be functionally checked
to verify system operation and compatibility with
the heat pump. Refer to the installation instruc-
tions for this equipment and perform a functional
checkout in accordance with the manufacturer's
instructions.
Optional Equipment — A functional checkout
should be performed in accordance with the
checkout procedures supplied with the equip-
ment.
Defrost Cycle Control — The Adaptive Demand
defrost controls the defrost cycle in response
to adaptive demand algorithm that uses coil
POWER
ALERT
TRIP
Figure 2. Comfort Alert
Module
TM Diagnostics
9