Carrier 38AUQ appendix Defrost Thermostats, Indoor Fan Off Delay, Defrost Speedup Functions

Page 24

Defrost Thermostats

These are temperature switches that monitor the surface tem- perature of the outdoor coil circuits. These switches are mount- ed on the liquid tube exiting the outdoor coil heating circuits. These switches close on temperature drop at 30°F (-1°C) and reset open on temperature rise at 80°F (27°C).

Indoor Fan Off Delay

The DFB can provide a 30 sec delay on Indoor Fan Off if the thermostat's fan selector switch is set on AUTO control. DIP Switch SW3 on the DFB selects use of the fan off time delay feature. Setting SW3 in the OPEN position turns the Fan Off Delay feature on; setting SW3 in the CLOSED position dis- ables this feature. The delay period begins when Y1 demand or W1 demand by the space thermostat is removed.

Defrost Speedup Functions

The DFB permits the servicer to speed-up the defrost cycle. There are two speed-up sequences: relative speed-up and an immediate forced defrost. Speed-up sequences are initiated by shorting jumper wires JMP17 and JMP18 together (see Fig. 22); use a straight-edge screwdriver.

Shorting the jumpers for a period of 1 to 3 secs reduces the de- frost timer periods by a factor of 0.1 sec/minute. (For example, the 90 min run period is reduced to 9 secs.) The DFB will step the unit through a Heating cycle and a Defrost cycle using these reduced time periods. This mode ends after the Defrost cycle.

Shorting the jumpers for a period of 5 to 20 secs bypasses the remaining continuous run period and places the unit in a Forced Defrost mode. If the controlling DFT is closed when this mode is initiated, the unit will complete a normal defrost period that will terminate when the controlling DFT opens or the 10 minute defrost cycle limit is reached. If the controlling DFT is open when this mode is initiated, the Defrost cycle will run for 30 secs. Both modes end at the end of the Defrost cycle.

24

Page 23 Page 25
Image 24
Page 23 Page 25
Contents Contents Safety ConsiderationsInstallation Guideline Replacement /Retrofit R22 to PuronInstallation 38AUQ*07-12 Unit Dimensions Pressurestat Settings psig High Cutout Operating Charge, Typical lb†Shipping Charge lb Qty...TypeOperating Weight kg Aluminum-Fin Coils Pressurestat Settings kPa High CutoutNominal Capacity kW Operating Charge, Typical kg†Service Options Model TypeType of Coil Refrigerant OptionsInstallation 38AUQ*07-12 Piping Recommendations Single-Circuit Unit Maximum Vertical SeparationPuron-duty Filter Driers Refrigerant Specialties Part Numbers Insulation for Vapor Line Exposed To Outdoor ConditionsInstall Accessories Field Power SupplyComplete Electrical Connections Units Without Factory-Installed Disconnect Units with Factory-Installed DisconnectConvenience Outlets All unitsInstalling Weatherproof Cover Convenience Outlet LocationField Control Wiring ThermostatElectrical Data 38AUQ*07-12 Hz Units PRE-START-UP START-UPAdvanced Scroll Temperature Protection Astp Adjust Refrigerant ChargeStart Unit Final Checks38AUQ*07 Charging Chart 38AUQ Wiring Diagram 208/230-3-60 shown Operating Sequence Base Unit ControlsRoutine System Maintenance ServiceQuarterly Inspection 30 days after initial start Refrigeration SystemField Refrigerant Access Ports Refrigerant System Pressure Access PortsLiquid Line Filter Drier Outdoor Coil Metering DevicesHeat Pump Controls Compressor ProtectionCrankcase Heater Commercial Defrost ControlDip Switch Position DefrostReversing valve control Compressor controlIndoor Fan Off Delay Defrost ThermostatsDefrost Speedup Functions Fans Service Valves 38AUQ*08 Exterior 38AUQ*12 Exterior Comfort Alert Diagnostic Module InputLED Status Codes LockoutOutdoor Coil Maintenance and Cleaning Recommendation Periodic Clean Water RinseRoutine Cleaning of Indoor Coil Surfaces LubricationService Parts Fastener Torque ValuesTorque Values Troubleshooting Appendix a Appendix BAppendix C Catalog No 38AUQ-01SIPreliminary Information CUT Along Dotted Linecut Along Dotted Line

38AUQ specifications

The Carrier 38AUQ is a versatile and efficient air conditioning unit designed to meet a variety of residential and light commercial cooling needs. Known for its advanced technology and robust performance, the 38AUQ model showcases Carrier's commitment to sustainability and energy efficiency.

One of the standout features of the Carrier 38AUQ is its use of variable-speed inverter technology. This allows the unit to adjust its cooling output in response to the temperature demands of the environment. By operating at multiple speed levels, it minimizes energy consumption and maximizes comfort, ensuring a consistent, quiet cooling experience.

The 38AUQ is equipped with a high-efficiency compressor, which helps to further enhance its energy performance. This component plays a critical role in ensuring that the unit operates smoothly, reducing both electricity bills and the environmental impact. Efficiency ratings often exceed industry standards, making the 38AUQ a suitable choice for those looking to reduce their carbon footprint while enjoying a comfortable indoor climate.

In terms of design, the Carrier 38AUQ boasts a compact and sleek profile that allows for easy installation in a variety of settings. Its durable construction is built to withstand harsh weather conditions, ensuring longevity and reliability. Additionally, an advanced air purification system is integrated, featuring filters that capture airborne particles, improving indoor air quality.

The unit also offers a range of smart features, including compatibility with smart home systems. Users can remotely control their air conditioning via smartphone apps, allowing for customizable settings and energy management from anywhere. This connectivity aligns with modern living preferences, enhancing convenience and control.

Furthermore, the Carrier 38AUQ is designed with noise reduction in mind. The advanced sound-absorbing materials and quiet operation of its fan and compressor make it one of the quieter air conditioning options on the market. This is particularly beneficial for residential applications, where noise can be a significant concern.

Overall, the Carrier 38AUQ combines cutting-edge technology, energy efficiency, and user-friendly features, making it a top choice for both homeowners and small business operators seeking reliable cooling solutions. Its commitment to performance and efficiency makes it a standout model in the Carrier air conditioning lineup.
Top Page Image Contents