Carrier 48/50PD05 Troubleshooting, Alarm Handling, Complete Unit Stoppage, Restart Procedure

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48/50PD

Loadshed Group Number (S.GRP)

This corresponds to the loadshed supervisory devices that reside elsewhere on the CCN network and broadcast loadshed and redline commands to its associated equipment parts. This variable will default to zero which is an invalid group number. This allows the loadshed function to be disabled until configured.

Redline Max Capacity (R.MXC)

This configuration tells the unit the maximum cooling/dehumidification capacity allowed active during a loadshed condition.

Redline Max Heat Stages (R.MXH)

This configuration tells the unit the maximum heating stages allowed to be on during a redline condition.

Loadshed Max Heat Stages (R.MXH

This configuration tells the unit the maximum heating stages allowed to be on during a loadshed condition.

The two Demand Limiting methods can be active simultaneously. The lowest cool capacity and heat stage limits imposed by either method are applied, and these “effective limits” are shown in the points CAPLIMIT (Run StatusCOOLLMT.C) and HSTGLIMT (Run StatusHEATLMT.H), respectively. In normal running mode, these limits will prevent capacity/stages from being added, or capacity/stages to be removed, as applicable. In test mode, these limits are ignored, and the user may continue to operate at full load.

The point MODEDMDL (Run StatusMODED.LMT) is used to show if any Demand Limiting is in effect that prevents the unit from operating either cooling or heating at full-capacity.

IMPORTANT: MODEDMDL may reflect that staging is NOT limited even though Loadshed is active or the network points are being forced, if the capacity/stage limits in effect are not less than the capacity/stages present in the unit.

If a more drastic mode of Demand Limiting is required, the network point HVACDOWN (Run StatusMODEHV.DN) can be used to prohibit the unit from selecting any HVAC mode, thus preventing the operation of the supply fan, compressors, condenser fans, and heat stages. This point must also be forced, and is reset automatically when not forced, and at POR.

Alarm Handling

There are a variety of different alerts and alarms in the system. Alerts are indicated by TXXX (where XXX is the alert number) on the display and generally signify that the improperly functioning circuit can restart without human interaction. If an alarm occurs, indicated by AXXX (where XXX is the alarm number), the damaged circuit will generally not restart without an alarm reset via the Scrolling Marquee display or CCN.

The response of the control system to various alerts and alarms depends on the seriousness of the particular alert or alarm. In the mildest case, an alert does not affect the operation of the unit in any manner. An alert can also cause a “strike.” A “striking” alert will cause the circuit to shut down for 15 minutes. This feature reduces the likelihood of false alarms causing a properly working system to be shut down incorrectly. If three strikes occur before the circuit has an opportunity to show that it can function properly, the circuit will strike out, causing the shutdown alarm for that particular circuit. Once activated, the shutdown alarm can only be cleared via an alarm reset.

However, circuits with strikes will be given an opportunity to reset their strike counter to zero. As discussed above, a strike typically causes the circuit to shut down. Fifteen minutes later, that circuit will once again be allowed to run. If the circuit is able to run for 1 minute, its replacement circuit will be allowed to shut down (if not required to run to satisfy requested stages). However, the “troubled” circuit must run continuously for a user defined time (ConfigurationCOOLRST.C) with no detectable problems

before the strike counter will be reset to zero. Default value is 5 minutes.

CCN Alarm Broadcast

Operators of CCN networks might not want to be notified of “striking” alerts for refrigerant circuits until the circuit has been shut down due to 3 strikes. Set the cooling configuration of Alert Each Strike (ConfigurationCOOLALM.N on display, ALM_NOW on CCN) to YES to broadcast each circuit strike alert. Set Alert Each Strike to NO to broadcast only circuit shut down. Alert Each Strike configuration is ignored during Service Test and all alerts are broadcast.

Alarm Relay Output

The alarm relay output is a normally open 24 vac output between field connection terminal board terminals C and X. Selection of which alerts and alarms will result in closing of the alarm relay may be set in the Alarm Relay Configuration (ConfigurationALM.O). Setting a configuration to YES will result in the alarm output relay, ALRM, status of ON and 24 vac between C and X when that particular condition is in an alarm state. Setting a configuration to NO will result in no action by the alarm output relay for that particular condition.

IMPORTANT: An accessory filter switch can be used along with the alarm relay output function to indicate dirty filter service need.

See the Troubleshooting section for more information on viewing, diagnosing, and clearing alerts and alarms.

TROUBLESHOOTING

The Scrolling Marquee display shows the actual operating conditions of the unit while it is running. If there are alarms or there have been alarms, they will be displayed in either the current alarm list or the history alarm list. (See Table 8.) The Service Test mode allows proper operation of the compressors, fans, and other components to be checked while the unit is not operating. See Service Test.

Complete Unit Stoppage

There are several conditions that can cause the unit not to provide heating or cooling:

SIf an alarm is active which causes the unit to shut down, diagnose the problem using the information provided in Alarms

and Alerts section below.

SCooling and heating loads are satisfied. S Programmed occupancy schedule.

S General power failure.

S Tripped CB1 or CB2 (24-volt transformer circuit breakers). S Unit is turned off through the CCN network.

S If outdoor-air temperature is less than the Compressor Lockout Temperature (CA.LO) configuration value, unit cannot cool.

S If outdoor-air temperature is greater than the Heating Lockout Temperature (HT.LO) configuration value, unit cannot heat.

Restart Procedure

Before attempting to restart the machine, check the alarm list to determine the cause of the shut down. If the shutdown alarm for a particular control function has occurred, determine and correct the cause before allowing the unit to run under its own control again. When there is problem, the unit should be diagnosed in Service Test mode. The alarms must be reset before the control function can operate in either Normal mode or Service Test mode.

Control Module Communication

Red LED

Proper operation of the MBB, ECB and AUX1 control boards can be visually checked by looking at the red status LEDs. When operating correctly, the red status LEDs should blink in unison at a rate of once every 2 seconds. If the red LED on the ECB and

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Contents Table of Contents Safety Considerations What to do if you smell gasGeneral Basic Control UsageScrolling Marquee Mode and Menu Display Structure System Pilott and Touch Pilot DevicesCCN Tables and Display START-UP Power Supply Internal WiringEvaporator Fan Condenser Fans and MotorsControls Quick SET-UP Accessories CCN CommunicationSetting an Occupied Time Schedule Weekdays Only for 730 to Fan StatusFilter Status TimeclockService Test Programming Operating SchedulesIndependent Outputs Fan TestThird Party Control Controls OperationUnit Configuration ModesGeneral Operating Sequence Occupancy DeterminationCompressor Operation Indoor Fan OperationOutdoor Fan Operation Economizer OperationUnoccupied Free Cooling Indoor Air Quality IAQ Cooling Modes Cool Supply Air Set Point Ventilation Mode For all units with EconomizersFor units with Enthalpy Control Demand Control VentilationHeating Modes Supply-Air Temperature Sensor SAT Gas Heat Start-UpTemperature Compensated Start Setting Up the SystemTemp Comp Strt Cool Factr TCS.C Temp Comp Strt Heat Factr TCS.HCarrier Comfort Network Ccnr Configuration Demand LimitTroubleshooting Alarm HandlingRestart Procedure Complete Unit StoppageAlarms and Alerts Communication FailuresAlert Code T073 Outdoor Air Temperature Thermistor Failure Alert Code T074 Space Temperature Thermistor FailureAlert Code T075 Supply Air Temperature Thermistor Failure Alarm Code A154 Serial Eeprom Hardware FailureAlarm Code T155 Serial Eeprom Storage Failure Error Alarm Code A156 Critical Serial Eeprom Storage Fail ErrorAlarm Code A200 Linkage Timeout Comm Failure Alarm Code A404 Fire ShutdownAlert Code T415 IAQ Input Out of Range Alert Code T416 OAQ Input Out of RangeComfortLink Alarm Codes Cooling Troubleshooting Digital Scroll Controller DSC Troubleshooting Cooling Service AnalysisFlash Code 4 ⎯ Locked Rotor DSC Red LED Flash CodesEconomizer Troubleshooting Economizer Service AnalysisHeating Troubleshooting Variable Frequency Drive VFD TroubleshootingPhase Loss Protection IGC Service Analysis Logic IGC Board LED Alarm Codes Electric Heat Service AnalysisLED FlashThermistor Troubleshooting Air TemperaturesRefrigerant Temperatures Thermistor/Temperature Sensor CheckTransducer Troubleshooting Forcing Inputs and OutputsSensor Trim Temp Voltage Resistance Drop Temp Voltage Resistance Temp F Drop Degree C Degree F Major System Components GeneralPressure Voltage Psig48PD Control Wiring Schematic 50PD Control Wiring Schematic 48/50PD Power Wiring Schematic and Legend Typical Unit Component Arrangement Setting Main Base Board MBBMBB Connections FIL.SCenter of the board. Do not change this setting Economizer Control Board ECBECB Connections RM.OCModulation Board AUX1 CommunicationDigital Scroll Control Board DSC CMP.AVariable Frequency Drive VFD Variable Frequency Drive VFDIntegrated Gas Control IGC Board Integrated Gas Control IGC BoardLow Voltage Terminal Strip TB1Accessory Navigatort Display Field-Installed AccessoriesScrolling Marquee Display Carrier Comfort Network Ccnr InterfaceSpace Temperature Sensor T-58 Space Temperature Sensor AveragingSpace Temperature Sensor Averaging Service Cleaning Coil Maintenance and Cleaning RecommendationPeriodic Clean Water Rinse Routine Cleaning of Round-Tube Coil SurfacesCondensate Drain Pan FiltersOutdoor-Air Inlet Screens Main Burner 48PDEvaporator Fan Service and Replacement Evaporator Fan Performance AdjustmentLubrication Evaporator Fan Belt Tension Adjustment Variable Frequency Drive VFD ReplacementCondenser-Fan Adjustment Economizer Operation During Power Failure Verify Sensor PerformanceEvacuation Refrigerant ChargeGas Valve Adjustment PuronR RefrigerantAltitude Compensation 48PG03-07 Elevation Natural GAS PropaneHigh Altitude Main BurnersFilter Drier Protective DevicesReplacement Parts Diagnostic LEDsRelief Devices Compressor Sound ShieldMode RUN Status Appendix a Local Display and CCN TablesStrt Alrmdisp = CCNOnly Generic = CCNMode Service Test Mode TemperaturesMode Pressures Mode SET Points Mode InputsMode Outputs OutputsMode Configuration HT.TY HTRMRT.H MOT.HIA.CF IA.FNII.CF II.FNTrim SPT.CSPT.T SAT.CMode Time Clock CCN only TablesMode Operating Modes OK.HT ACT.HEN.LO AQ.DVMode Alarms Expansion Range Default CCN CCN Point CCN WriteExpansion Range Units TABLE/SUB---TABLE StatusAppendix B VFD Information VFD Terminal DesignationsVFD Configurations Standard Display Mode VFD OperationVFD Modes Start Up with AssistantParameters Mode Start-Up Assistant ModeChanged Parameters Mode Drive Parameter Backup ModeVFD Diagnostics VFD Maintenance Correcting AlarmsHistory Heat SinkFault Codes 101---105201---206 1000 10011002 1003Alarm Codes Maintenance IntervalsMaintenance Interval Main Fan Replacement Control Panel CleaningBattery Replacement Appendix C START-UP Data Fan Performance 48PDD05 Vertical UnitsFan Performance 48PDE05 Vertical Units AirflowFan Performance 48PDD06 Vertical Units Fan Performance 48PDE06 Vertical Units Rpm Bhp 1500Available External Static Pressure in. wg CFMFan Performance 48PDD05 Horizontal Units Fan Performance 48PDE05 Horizontal UnitsBhp Rpm Fan Performance 48PDD06 Horizontal Units 1026 1086 1144 1199 1253Fan Performance 48PDE06 Horizontal Units Fan Performance 50PD05 Vertical Units Fan Performance 50PD06 Vertical UnitsFan Performance 50PD05 Horizontal Units Bhp Rpm 1500General Notes for FAN Performance Data Tables Appendix D Additional START-UP Data Control SET Point and Configuration LOG Indicate Unit Settings belowCCN Point Entry 103 104 Unit START-UP Checklist PRE-START-UP106

48/50PD05 specifications

The Carrier 48/50PD05 is a remarkable addition to Carrier's lineup of rooftop units, offering advanced cooling and heating solutions for commercial applications. Designed for medium-sized buildings, this unit is well-suited for both new installations and as a replacement for older systems, thanks to its versatile features and efficient performance.

One of the standout features of the 48/50PD05 is its energy efficiency. It incorporates state-of-the-art technology to achieve high Seasonal Energy Efficiency Ratios (SEER) and EER ratings, reducing operational costs while delivering superior comfort. The unit is also compliant with the latest energy regulations, making it an environmentally friendly choice for building owners concerned about sustainability.

The 48/50PD05 is equipped with a highly efficient scroll compressor, which not only enhances performance but also contributes to quiet operation. This is a significant advantage in commercial spaces where noise levels need to be kept in check for comfort and productivity. Additionally, the unit includes advanced airflow design, ensuring even distribution of conditioned air throughout the space.

Technologically, the Carrier 48/50PD05 features Carrier's Infinity Control system, which allows for precise control of indoor climate. This intelligent control mechanism can be integrated with smart building management systems, enabling users to monitor and manage energy use effectively. Wi-Fi connectivity is also available, providing remote access for real-time adjustments and diagnostics.

Durability is another characteristic of the 48/50PD05. Constructed with high-quality materials, the unit withstands various environmental conditions, ensuring longevity and reliability. Moreover, the modular design facilitates easy maintenance, making service procedures efficient and cost-effective.

In addition to cooling, the Carrier 48/50PD05 offers heating capabilities, often utilizing gas or electric heating options that can be tailored to the specific needs of a building. The unit can also be equipped with integrated economizers, allowing for free cooling during suitable outdoor conditions, further enhancing energy savings.

Overall, the Carrier 48/50PD05 stands out as a high-performance HVAC solution that combines efficiency, technology, and durability. It provides building owners with a versatile tool to ensure comfort while minimizing their environmental footprint. With a strong emphasis on energy savings and advanced control features, this rooftop unit is a smart investment for any commercial property.