Carrier 38AUZ appendix Operating Sequence, Routine System Maintenance, Base Unit Controls

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OPERATING SEQUENCE

Base Unit Controls

Indoor (Supply) Fan

The indoor fan contactor (IFC) is remotely located at the fan coil or fan section. If the thermostat fan operation is selected as Continuous, the IFC is energized and the indoor (supply) fan motor runs continuously. If the thermostat fan operation is selected as Automatic, the IFC will be energized on a call for Cooling; indoor (supply) fan motor runs. When thermostat call for Cooling is satisfied, the IFC is de-energized and indoor (supply) fan motor stops.

Cooling, Unit Without Economizer

On a thermostat call for Cooling, IFC will be energized and indoor (supply) fan motor runs. Thermostat contact TC1 closes; terminal Y1 at 38AU unit receives 24-v. 24-v received at CADM terminal Y. If anti-recycle time delay period has not expired, CADM relay will remain open, preventing compressor start. When safety pressure switches are closed, the liquid line solenoid valve opens. When CADM time delay expires, the compressor contactor is energized; both outdoor fan motors start and compressor starts.

When space cooling load is satisfied, thermostat contacts TC1 open, removing 24-v at 38AU terminal Y. Compressor and outdoor fan motors stop. Liquid line solenoid valve is de-energized and valve closes. CADM begins its three-minute anti-recycle time delay.

If either the Low Pressure Switch or High Pressure Switch opens while thermostat contact TC1 remains closed, the compressor contactor is de-energized (both fan motors and compressor stop) and liquid line solenoid is de-energized (valve closes). CADM initiates a TRIP event (cooling demand sensed at CADM terminal Y but no current is measured at T1, T2, T3 motor sensors); CADM relay opens and RED LED is illuminated. TRIP condition maintains lockout of compressor operation until CADM is manually reset. Reset CADM by cycling unit main power.

Complete system shutdown may be caused by loss of main power, open compressor internal overload, open low-pressure or high-pressure switch, or a fault detected by the CADM logic. Compressor operation without cooling may indicate the compressor’s ASTP feature is active (unit sizes 12 and 14 only); disconnect unit power and allow compressor to cool. See Service section for further details.

Cooling, Unit With Economizer

Refer to fan coil unit installation instructions and economizer accessory installation instructions for operating sequences when system is equipped with accessory economizer.

Heating

Refer to fan coil unit installation instructions and accessory heating device installation instructions for operating sequences in heating mode.

ROUTINE SYSTEM MAINTENANCE

These items should be part of a routine maintenance program, to be checked every month or two, until a specific schedule for each can be identified for this installation:

Quarterly Inspection (and 30 days after initial start)

Indoor section

Condenser coil cleanliness checked.

Return air filter replacement

Outdoor hood inlet filters cleaned

Belt tension checked

Belt condition checked

Pulley alignment checked

Fan shaft bearing locking collar tightness checked

Condensate drain checked

Seasonal Maintenance

These items should be checked at the beginning of each season (or more often if local conditions and usage patterns dictate):

Air Conditioning

Condenser fan motor mounting bolts tightness

Compressor mounting bolts

Condenser fan blade positioning

Control box cleanliness and wiring condition

Wire terminal tightness

Refrigerant charge level

Evaporator coil cleaning

Evaporator blower motor amperage

Heating

Power wire connections

Fuses ready

Manual-reset limit switch is closed

Economizer or Outside Air Damper

Inlet filters condition

Check damper travel (economizer)

Check gear and dampers for debris and dirt

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Contents Contents Safety ConsiderationsInstallation Guideline Replacement /Retrofit R22 to Puron38AUZ*07-14 Unit Dimensions Compressor Unit Size 38AURefrigerant Type Condenser FansNominal Capacity kW Operating Weight kg Aluminum-Fin Coils StandardPressurestat Settings kPa High Cutout Operating Charge, Typical kg† Shipping Charge kgType of Coil Service OptionsModel Type Refrigerant OptionsInstallation Liquid Line Data 38AUZ*07-14 60 Hz Units Refrigerant Piping Sizes 38AUZ*07-14 60 Hz UnitsComplete Electrical Connections Install AccessoriesField Power Supply Refrigerant Specialities Part NumbersConvenience Outlets Units Without Factory-Installed DisconnectUnits with Factory-Installed Disconnect All unitsInstalling Weatherproof Cover Unit Connect Primary TransformerConnections Terminals Weatherproof Cover Installation ThermostatElectrical Data 38AUZ*07-14 Hz Units PRE-START-UP START-UPSystem Check Advanced Scroll Temperature Protection Label 38AUZ*07 Charging Chart 38AUZ*14 Charging Chart Routine System Maintenance Operating SequenceBase Unit Controls Service Comfort Alert Diagnostic ModuleInput LED Status Codes LockoutCadm Troubleshooting Compressor ProtectionLubrication Field Refrigerant Access Ports Novation Coil Cleaning and MaintenanceRepairing Novation Condenser Tube Leaks Factory High-Flow Access PortsCompressor Stops on HIGH-PRESSURE Switch TroubleshootingProblem Solution Compressor does not RUN Fastener Torque ValuesUnit Operates TOO Long or Continuously Problem Solution Compressor Cycles on LOW-PRESSURE SwitchCompressor Running but Cooling Insufficient System is NoisyAppendix Catalog No 38AU-01SI Preliminary Information CUT Along Dotted Linecut Along Dotted Line

38AUZ specifications

The Carrier 38AUZ series is a line of air conditioning systems specifically designed to deliver optimal comfort and energy efficiency for both residential and commercial applications. Known for their advanced technology and robust performance, these units are ideal for a variety of climate conditions, ensuring consistent cooling and heating throughout the year.

One of the standout features of the Carrier 38AUZ series is its inverter technology, which allows the unit to adjust its cooling or heating output in real-time based on the ambient conditions. This results in lower energy consumption and reduced operating costs, making the system not only environmentally friendly but also budget-conscious. By minimizing temperature fluctuations, the inverter design promotes a more stable and comfortable indoor environment.

The 38AUZ units are equipped with high-efficiency compressors that enhance the system’s performance. These compressors operate quietly and efficiently, contributing to a lower noise level that is ideal for residential settings. Furthermore, they come with variable speed fan motors which offer precise airflow control, allowing users to customize their comfort level while ensuring energy savings.

In terms of build quality, the Carrier 38AUZ is constructed using durable materials designed to withstand harsh weather conditions. Its compact design allows for easy installation and maintenance, making it an ideal choice for urban environments where space is limited. Additionally, the system features a corrosion-resistant cabinet that extends its lifespan and maintains aesthetic appeal.

The 38AUZ series also includes a range of advanced control options. Users can benefit from smart technology integration, allowing for remote temperature control and scheduling through mobile devices. This feature not only enhances convenience but also provides users with complete control over their energy usage.

Moreover, the Carrier 38AUZ units come with various capacity options, catering to different space requirements. With a focus on energy efficiency, these systems often meet or exceed industry standards, including SEER ratings, ensuring optimal performance without sacrificing energy consumption.

In summary, the Carrier 38AUZ series is an exemplary choice for anyone looking to invest in a reliable, efficient, and advanced air conditioning system. With its inverter technology, high-efficiency compressors, smart control options, and durable construction, the 38AUZ not only delivers exceptional comfort but also promotes energy conservation, making it a smart choice for sustainable living.