Nordyne R-410A - Manual (Page 10)

10
Functional Checkout:
CAUTION:
If equipped with a compressor
crankcase
heater, wait 24 hours prior
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 — Set the thermostat function
switch to COOLING and 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 Time Delay Relay (Select Models): A
time delay relay may be provided with the unit and
must be installed in the indoor section. The relay
will keep the indoor blower running an additional
40 seconds for increased cooling effi ciency after
the outdoor unit shuts off. The relay has four
terminals and one mounting hole.
Connect terminal “1” to load side of blower relay.
Connect terminal: “2” to terminal “R” of T’stat.
Connect terminal “3” to common terminal at
blower relay or transformer. Connect terminal
“4” to terminal “G” on T’stat.
Low-Pressure Switch (Select Models) — A
low-pressure switch is factory-installed in select
models only. If provided, this switch is 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.
High-Pressure Switch — A high-pressure
switch is factory-installed and located in the
compressor discharge line internal to the outdoor
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 Diagnostics (Select Models)
— The Comfort Alert TM diagnostics module
facilitates troubleshooting heat pump and air
conditioning system failures. This Comfort
Alert
TM module is designed only for single-phase
systems with scroll compressors that have
internal overload protection. By monitoring and
analyzing data from the compressor and the
thermostat demand, the module can 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.
NOTE: This module does not provide safety
protection! The Comfort Alert
TM module is a
monitoring device and cannot control or shut
down other devices.
LED Description (See Figure 2)
POWER LED (Green): indicates voltage is present
at the power connection of the module.
ALERT LED (Yellow): communicates an
abnormal system condition through a unique
fl ash code. The ALERT LED will fl ash a number
of times consecutively, pause and then repeat
the process. The number of consecutive
fl ashes, defi ned as the Flash Code, correlates
to a particular abnormal condition. Detailed
descriptions of specifi c ALERT Flash Codes are
shown in Table 1 of this manual.