Carrier 38AU appendix Comfort Alert Diagnostic Module, Input Terminal Voltage

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Comfort Alert Diagnostic Module

The Comfort Alert Diagnostic Module (CADM) monitors and analyzes data from the Copeland Scrollthree-phase compressor and the thermostat demand. The CADM also provides a 3-minute anti-recycle time delay to compressor cycling. Each compressor has a separate CADM module.

The CADM detects causes for electrical and system related failures without any sensors. Flashing LEDs communicate the Alert codes to guide service technicians in accurately and quickly troubleshooting the system and determining root cause for the failure.

Inputs to the CADM include 24-vac power, thermostat Y1 or Y2, compressor contactor coil (common side) and compressor power leads (from the compressor contactor).

Input

Terminal

Voltage

 

 

 

Control

R

24-V

Power

 

 

 

 

 

Control

C

24-V

Common

 

 

 

 

 

Cooling

Y

24-V

 

 

 

Contactor

P

24-V

Coil

 

 

 

 

 

Line A

T1

Line

 

 

 

Line B

T2

Line

 

 

 

Line C

T3

Line

 

 

 

Control of the compressor contactor coil is through a normally-closed (power on the module) contact between terminals P and C.

Communications of status and alert conditions is through three LEDs located on the top edge of the module housing (see Fig. 32): POWER (green), ALERT (yellow), and TRIP (red).

The POWER LED indicates the presence of control power to the CADM.

The ALERT LED indicates an abnormal condition exists in the system through a flash code. The ALERT LED will blink a number of times consecutively, pause and the repeat the process. The number of blinks, defined in Table 11, correlates to a particular abnormal condition; troubleshooting tips are provided for each Alert code. Reset of the ALERT may be automatic or manual. If the fault condition causing the Alert is self-corrected, the Alert code will be removed and the CADM will automatically reset and allow the system to restart normally. Manual reset requires that main power to the 38AU unit be recycled after the cause for the Alert condition has been detected and corrected.

POWER (GRN)

ALERT (YEL)

TRIP (RED)

C10086

Fig. 32 - CADM Housing/LED Locations

The TRIP LED indicates either a time-delay period is currently active (RED LED is blinking) or the module has locked out the compressor (RED LED is on steady). A lockout condition will occur when the CADM detects a thermostat demand at input Y but there is no power at the compressor line terminals T1 or T2 or T3. This lockout can occur due to a safety switch (LPS or HPS) opening and de-energizing the compressor contactor, the compressor-motor internal overload opens, or other internal power interruption has occurred. Reset of the TRIP LED requires that unit main power be recycled after the loss of power to the compressor condition has been detected and corrected.

Simultaneous Blinking of YELLOW and RED LEDs indicates control power input to the CADM is low. Check control circuit transformer and wiring.

Troubleshooting the CADM Wiring – Flashing LEDs also indicate wiring problems to the CADM. See Table 12 for discussion of additional LED flash codes and troubleshooting instructions.

38AU

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Contents Contents Installation, Start---Up Service InstructionsReplacement/Retrofit R-22 to PuronR Safety ConsiderationsInstallation Guideline Unit Damage Hazard InstallationRtpf UnitMchx 38AUD*25 38AUZ*25Condenser Fans Unit Size 38AURefrigerant TYPE‡ CompressorScroll Pressurestat Settings kPa High CutoutNominal Capacity kW Rtpf Shipping Charge kgFace Area sq ft total Rows/Fins per inch FPI Rtpf Shipping Charge A/B lbOil Charge A/B oz Qty...r/s Motor Hp Nema Diameter mm Operating Weight kg Novation Coil Al TubeRtpf Shipping Charge A/B kg Oil Charge A/B LU Z a 2 5 a 0 G 6 a 0 a 0 a Do not Bury Refrigeration Lines InstallationMatching 38AU Model To Evaporator Coil Jobsite SurveyCheck 38AU Model with Evaporator Coil Connections Provide Safety ReliefSlab Mount Equivalent Lengths for Common Fittings ft38AUZ 16-25 Piping Recommendations Single-Circuit Unit Liquid LiftSuction Riser Hot Gas Bypass 38AUD 16-25 Piping Recommendations Two-Circuit UnitVertical Separation outdoor unit above indoor unit Insulate Suction LinesRefrigerant Specialties Part Numbers Install Filter Driers and Moisture IndicatorsMake Piping Connections Install Liquid Line Solenoid ValveCapacity Control Liquid Line Solenoid Valve Selecting an AccumulatorPreliminary Charge Evacuation/DehydrationAll Units Field Power SupplyUnits with Factory-Installed Disconnect Fire HazardElectrical Operation Hazard Convenience OutletsConvenience Outlet Utilization Notice Label Field Control WiringThermostat Control Transformer WiringUnbalanced 3-Phase Supply Voltage Unit Wire/Fuse or Hacr Breaker Sizing DataPreliminary Checks PRE-START-UPSTART-UP System CheckStart Unit Advanced Scroll Temperature Protection AstpAdjust Refrigerant Charge Using plotted operating pointFinal Checks 38AUZ*25 Check Compressor Oil Level38AUD*16 Charging Chart Novation 38AUZ*16 Charging Chart Rtpf 38AUD*16 Charging Chart Rtpf 38AUD*25 Charging Chart Rtpf Typical 38AUZ Wiring Diagram 15 Ton 230V Tandem Unit Shown Typical 38AUD Wiring Diagram 15 Ton 230V Dual Unit Shown Base Unit Controls Operating SequenceEquipment Damage Hazard Routine System MaintenanceService Refrigeration SystemLiquid Line Filter Drier Field Refrigerant Access PortsFactory High-Flow Access Ports Input Terminal Voltage Comfort Alert Diagnostic ModuleLockout LED Status CodesCompressor Protection 38AUD Size 16 Cabinet LPS 38AUZ,D Size 25 Cabinet 38AUZ*25 Compressor Assembly Rear View NOVATIONt Type Novation Coil Cleaning and MaintenanceRepairing Novation Condenser Tube Leaks Coil Type IdentificationUnit Reliability Hazard Routine Cleaning of Round-Tube Plate Fin Rtpf CoilsReplacing NOVATIONt Condenser Coil Fastener Torque Values TroubleshootingProblem Solution Compressor does not RUN Compressor Stops on HIGH-PRESSURE SwitchSystem is Noisy Problem Solution Compressor Cycles on LOW-PRESSURE SwitchCompressor Running but Cooling Insufficient Unit Operates TOO Long or ContinuouslyAppendix B Wiring Diagram ListAppendix a Operation Low Ambient Option Factory InstalledTroubleshooting Appendix C38AUZ*16 & 38AUD*16 Novation 38AUZ*16/25 & 38AUD*16/25 Rtpf Motormaster Sensor LocationDimensions --- MM Unit Baffle Wind Baffle DimensionDimensions --- Inches Unit Baffle Wind Baffles Fabrication 15 Ton Wind Baffle Brackets Fabrication Front Front Back Left Right Catalog No 38AU---09SI II. PRE-START-UP Outdoor Unit START-UP ChecklistCheck Voltage Imbalance