Nordyne R-410A Functional Checkout, Comfort AlertTM Diagnostics Select Models

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 airflow 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 efficiency 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 AlertTM Diagnostics (Select Models)

—The Comfort AlertTM diagnostics module facilitates troubleshooting heat pump and air conditioning system failures. This Comfort AlertTM 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 flashing 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 AlertTM module is a monitoring device and cannot control or shut down other devices.

LED Description (See Figure 2)

POWERLED(Green):indicatesvoltageispresent at the power connection of the module.

ALERT LED (Yellow): communicates an abnormal system condition through a unique flash code. The ALERT LED will flash a number of times consecutively, pause and then repeat the process. The number of consecutive flashes, defined as the Flash Code, correlates to a particular abnormal condition. Detailed descriptions of specific ALERT Flash Codes are shown in Table 1 of this manual.

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