Nordyne R-410A Indoor Blower, Short Cycle Protection, Defrost Cycle Control, Control Diagnostic

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verify system operation and compatibility with the heat pump. Refer to the installation instructions for this equipment and perform a functional checkout in accordance with the manufacturer’s instructions.

Indoor Blower

1.Turn the fan mode to ON. Verify that the indoor blower is operating and that airfl ow is not restricted.

2.Set the fan mode back to AUTO. Blower will operate at a decreased speed on continuous fan.

Short Cycle Protection

1.With the system operating in COOLING mode, record the setpoint temperature setting of the thermostat.

2.Gradually raise the setpoint temperature until the outdoor unit and indoor blower de- energize.

3.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.

4.After approximately 3 minutes, verify that the outdoor unit energizes and the temperature of the air supplied to the facility is cooler than ambient temperature.

Defrost Cycle Control

The defrost cycle is controlled by an Adaptive Demand Defrost algorithm that monitors coil temperature and ambient temperature. Other features of the of the demand defrost board include:

4 Field selectable defrost termination temperatures (50° F - 80° F coil temperature).

Field selectable compressor delay feature.

High pressure and low pressure switches.

Sensing of second stage compressor demand.

Test/speed up capability.

Anti short cycle timer (3 minutes) for compressor protection.

On board diagnostics with fl ashing LED for quicker troubleshooting. See Table 2.

Diagnostic Description

LED Status

 

 

Control Fault (No Power)

Off

Normal Operation

On

ASCD Delay Active

1 Flash

(with compressor demand)

 

 

 

Low Pressure Switch Lockout

2 Flashes

High Pressure Switch Lockout

3 Flashes

Ambient Sensor Fault

4 Flashes

Coil Sensor Fault

5 Flashes

Table 2. Control Diagnostic

Control is uncalibrated when power is applied. Calibration occurs after a defrost cycle. The control initiates this sacrifi cial defrost after 34 minutes of accumulated compressor run time in heating with coil temperature below 35° F. The defrost cycle terminates if coil sensor reaches selected termination temperature or after 14 minutes defrost.

Defrost function is disabled if coil temperature is above 35° F. If Ambient sensor is detected as open or shorted, demand defrost will not operate and control will revert to time/temperature defrost operation. If the outdoor coil sensor is detected as open or shorted, the control will not perform demand or time/temperature defrost operation. NOTE: When the defrost cycle initiates, there will be a 30 second compressor delay going into and out of the defrost cycle. This delay may be removed by removing P6 connector on the board.

This 2-stage unit will defrost in second stage regardless of the stage called for by the thermostat.

NOTE: All units are shipped from the factory with the default termination temperature set at 70° F.

Defrost Test Procedure

1. Terminals R - C must have 18-30VAC present between them in order for defrost sequences to be initiated.

2With heat mode thermostat demand (Y connected to R), short and hold the TEST pins together. This will energize reversing valve to initiate a forced defrost. NOTE: This will bypass the ASCD and allow the high stage compressor to come on immediately (if the REMOVE FOR NO DELAY jumper at P6 is removed). If the REMOVE FOR NO DELAY jumper at P6 is installed, the compressor will energize immediately following a 30-second delay.

3.Remove the short on the TEST pins.

If the Coil temperature is above theTerminate Temperature selection setting, the defrost cycle will be terminated (reversing valve will de-energized).

If the coil temperature is below theTerminate Temperature election setting, the defrost cycle will continue for 14 minutes or until the coil temperature rises above the Terminate Temperature selection setting.NOTE:Short the TEST pins for 1 second or more to force the control out of defrost and back to heating mode (reversing valve de-energized). Compressor will turn on immediately (if the REMOVE FOR NO DELAY jumper is removed).

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Contents User’s Manual / Installation Instructions Page User Information Safety Information About the Heat PumpOperating Instructions System Maintenance TroubleshootingWarranty Information Labels, Tags, and Precautions Pressures within the SystemBrazing Operations Installing the Indoor Unit Installing the Outdoor UnitGeneral Information Site PreparationElectrical Connections Control Circuit Wiring Copper Wire Size GroundingLow-Pressure Switch High-Pressure SwitchComfort AlertTM Diagnostics Module VAC Power WiringStartup and Adjustments Functional CheckoutsDiagnostic Description LED Status Control DiagnosticDefrost Test Procedure Indoor BlowerAnti Short Cycle Timer Test Adjustment of Refrigerant ChargeCooling Charging Charts 450 425 400 375 350 325 300 275 Heating Charging Chart LED Diagnostics LEDShort Cycling Thermostat demand signal is intermittent Module Wiring Troubleshooting LED¢708868b¤
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R-410A specifications

Nordyne R-410A is a widely recognized refrigerant used in modern air conditioning and heat pump systems, known for its efficiency and environmentally friendly attributes. As a hydrofluorocarbon (HFC) refrigerant, R-410A has become the preferred choice for many manufacturers seeking to meet stringent environmental regulations while providing superior cooling performance.

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R-410A is also non-ozone-depleting, which sets it apart from many traditional refrigerants. While older refrigerants have been phased out due to their potential harm to the ozone layer, R-410A presents a sustainable alternative that aligns with environmental goals. It features a zero ozone depletion potential (ODP), making it a responsible choice for installations concerned with ecological impact.

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Another characteristic of R-410A is its ability to operate at lower temperatures, which enhances its versatility. This capability allows for the design of systems that can function efficiently in a wider range of climate conditions. As a result, HVAC technicians and contractors benefit from its reliability and performance, leading to less frequent maintenance and enhanced customer satisfaction.

Lastly, R-410A systems are equipped with advanced components that improve overall functionality. These systems often include variable-speed compressors, which optimize energy use based on cooling demand, and advanced refrigerant management technologies that ensure safe and efficient operation.

In conclusion, Nordyne R-410A stands out as a superior refrigerant due to its energy efficiency, environmental benefits, and adaptability across a range of HVAC applications. As the industry continues to innovate and shift toward sustainable solutions, R-410A remains at the forefront of refrigerant technology, ensuring homeowners and businesses alike enjoy efficient and eco-friendly cooling options.