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

Outdoor Unit — Ensure the outdoor coil and
top of the unit are free from obstructions and
debris, and all equipment access/control panels
are in place.
Using extreme caution, apply power to the unit
and inspect the wiring for evidence of open,
shorted, and/or improperly wired circuits.

Functional Checkout:

!
CAUTION:
These units have a crankcase heater
factory installed. Wait 24 hour
to performing a function checkout to allow
for heating of the compressor crankcase.
Failure to comply may result in damage
and could cause premature failure of the
system.
Indoor Blower — Turn the fan switch to ON.
Verify that the indoor blower is operating and
that airfl ow is not restricted. Set the fan switch
back to AUTO. Blower will operate at a decreased
speed on continuous fan.
2-Speed Outdoor Fan Motor (Select
Models) — If unit utilizes a 2-speed condenser
fan motor, this motor will operate on low speed
when in low cooling, and on high speed when
in high cooling. A relay within the control area
switches the fan motor from low to high speed
using the call for high cooling as the trigger.
Low-Pressure Switch — A low-pressure switch
is factory-installed and located in the suction
line internal to the outdoor unit. The switch is
designed to protect the compressor from a loss
of charge. Under normal conditions, the switch
is closed. If the suction pressure falls below 5
psig, then the switch will open and de-energize
the outdoor unit. The switch will close again
once the suction pressure increases above 20
psig. Please note that the switch interrupts the
thermostat inputs to the unit. Thus, when the
switch opens and then closes, there will be a 5
minute short cycling delay before the outdoor
unit will energize.
Discharge Temperature Limit — A discharge
temperature limit is factory installed and located
on the compressor discharge line internal to the
outdoor unit within 5 inches of the compressor
discharge. The limit is designed to protect the
8
compressor from abnormal temperatures that
may occur if there is a loss of charge. Under
normal conditions, the switch is closed. If the
discharge temperature rises above 270
then the switch will open and de-energize the
outdoor unit. The switch will close again once the
temperature decreases below 190
that the switch interrupts the thermostat inputs to
the unit. Thus, when the switch opens and then
closes, there will be a 5 minute short cycling delay
before the outdoor unit will energize.
High-Pressure Switch — A high-pressure
switch is factory-installed and located in the
compressor discharge line internal to the outdoor
s prior
unit. The switch is designed to de-energize the
system when very high pressures occur during
abnormal conditions. Under normal conditions,
the switch is closed. If the discharge pressure
rises above 575 psig, then the switch will open
and de-energize the outdoor unit. The switch
will close again once the discharge pressure
decreases to 460 psig. Please note that the switch
interrupts the thermostat inputs to the unit. Thus,
when the switch opens and then closes, there
will be a 5 minute short cycling delay before the
outdoor unit will energize.
Short Cycle Protection — With the system
operating in COOLING mode, note the setpoint
temperature setting of the thermostat, and
gradually raise the setpoint temperature until
the outdoor unit and indoor blower de-energize.
Immediately lower the setpoint temperature of
the thermostat to its original setting and verify
that the indoor blower is energized and that the
outdoor unit remains de-energized. Verify that,
after approximately 5 minutes, the outdoor unit
energizes and that the temperature of the air
supplied to the facility is cooler than ambient
temperature.
Comfort Alert
TM
Alert diagnostics module is a breakthrough
innovation for troubleshooting heat pump and
air conditioning system failures. The module
installs easily in the electrical box of the
outdoor unit near the compressor contactor.
By monitoring and analyzing data from the
Copeland scroll compressor and the thermostat
demand, the module can accurately detect the
cause of electrical and system related failures
without any sensors. A fl ashing LED indicator
communicates the ALERT code and guides the
service technician more quickly and accurately
to the root cause of a problem.
o F. Please note
TM
Diagnostics — The Comfort
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