American Standard UV05 manual Special Purpose Unit Modes, Discharge Air DA Heat State State

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Description of Operation

The CO2 demand controlled ventilation function (optional) is active (see “CO2 Demand Controlled Ventilation (optional)” on page 34), and the OA damper is adjusted as needed to maintain the CO2 set point.

Figure 15: Mech state operation (occupied mode and auto fan)

Discharge Air (DA) Heat State (State 4)

The DA Heat state is a “normal” state during Cool mode. The DA Heat state typically is active when reheat is required to maintain DATS while maintaining the required OA damper position. The DA Heat state can also be made active if the optional CO2 DCV feature is provided and CO2 levels are high, requiring the OA damper to open beyond what is required for economizer cooling.

When DA Heat state is active, the UVC uses the units heating capability as needed to maintain VCLL. The CO2 demand controlled ventilation function (optional) is active (see “CO2 Demand Controlled Ventilation (optional)” on page 34), and the OA damper is adjusted as needed to maintain the CO2 set point.

Low Limit State (State F)

The Low Limit state is a “non-normal” state during Cool mode. The Low Limit state typically follows the DA Heat state when the UVC reaches 100% heat and still cannot maintain VCLL.

When the Low Limit state becomes active, the Low Limit PI-loop overrides the OAD minimum position (see “Outdoor Air Damper Operation” on page 32) and adjusts the OAD toward closed as necessary to maintain the DAT set point (see “Discharge Air Temperature Control” on page 29).

Cant Cool State (State C)

The Cant Cool state is a “non-normal” state during Cool mode. The Cant Cool state typically becomes active when both primary (economizer) and secondary (compressor) cooling are not available (or they are disabled) or when an IAT, DAT or OAT sensor failure occurs.

When the Cant Cool state becomes active, no cooling is available.

Special Purpose Unit Modes

There are some additional UVC modes that are considered special purpose unit modes. These special purpose modes include Pressurize, Depressurize, Purge, Shutdown, and Energy Hold Off. These modes force the UVC to perform very specific and limited functions. Use these with caution and only for short periods as needed.

McQuay OM 751

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Contents DX Cooling Only Software Model UV05 Group Applied SystemsDate November Introduction UVC Configuration ParametersGetting Started Description of OperationModel-specific unit ventilator installation literature Accessory-specific installation literatureDescription Manual # Software program literature Extreme temperature can damage system componentsAcronyms/Abbreviations Acronyms and abbreviationsDescription Acronym Abr OCS Display Format Using the Keypad/DisplayKeypad Functions Security LevelsON/STOP Key and LED Mode KeyFAN Key Arrow KeysViewing Actual Indoor Air Temperature IAT Using the Keypad/DisplayMenu Reference Changing Set PointsRW1 Abr Description DefaultChlo State Programming Description of OperationUVC Unit Modes Complete UVC-state diagramUVC state names and numbers OFF Mode StateNormal UVC modes State names DecimalFan Only Mode State a Night Purge Mode StateEmergency Heat Mode Super State Full Heat State StateCant Heat State State D Auto Mode Heat Mode Super StateHeat State State Cool Mode Super State Low Limit State State ECant Heat State State B Econ State State Cool mode super state diagramMech State State Econ Mech State StateDischarge Air DA Heat State State Special Purpose Unit ModesLow Limit State State F Cant Cool State State CDepressurize Mode Pressurize ModePurge Mode Shutdown ModeSpecial purpose UVC unit mode priority Unit Mode PriorityNormal UVC mode priority Priority resultUnoccupied Mode Occupied ModeStandby Mode Occupancy mode priorityAdditional Occupancy Features Networked Space Temperature Sensor Capability Space Temperature Set PointsNetworked Set Point Capability Networked Set Point Offset CapabilityEffective Set Point Calculations Remote Wall-Mounted Sensor with +/-3F Adjustment optionalSet point calculation examples Example a Example B GivenEffective set point calculations Proportional Integral PI Control Loops Discharge Air Temperature ControlPI loop list PI loopsProportional Band PI Control ParametersIndoor Air Fan Operation Integral TimeOccupied, Standby, and Bypass Operation Outdoor Air Damper Operation Economizer enable EconomizerOA temp sensor Space humidity Networked Outdoor Humidity Sensor Capability Networked Space Humidity Sensor CapabilityCO2 Demand Controlled Ventilation optional Networked Space CO2 Sensor CapabilityAshrae Cycle Compressor OperationCompressor Envelope Compressor Cooling LockoutCompressor Start Delay Compressor Minimum On and Off TimersFloating-Point Actuator Auto-Zero, Overdrive and Sync Outdoor Air Fan OperationRemote Shutdown Input Signal Unoccupied Input SignalVentilation Lockout Input Signal External Binary InputsLights On/Off Signal Exhaust Interlock Input SignalFault Signal External Binary OutputsAuxiliary Heat Signal Exhaust Fan ON/OFF SignalAuxiliary heat start/stop calculation Start/Stop CalculationExpansion board Inputs and outputs, software model 05-DX cooling onlyAlarm and Fault Monitoring Alarm and fault code summaryPriority Fault description Reset Keypad Compressor Envelope Fault F2 DX Pressure Fault F1Space Temp Sensor Failure F0 Discharge Air DX Cooling Low Limit Indication F3Space Coil DX Temp Sensor Failure F5 Condensate Overflow Indication optional F4Outdoor Temp Sensor Failure F6 Discharge Air Temp Sensor Failure F7Troubleshooting Temperature Sensors Temperature versus resistance Troubleshooting Humidity SensorsHumidity versus voltage Troubleshooting Carbon Dioxide CO2 SensorsCO2 versus voltage table RH % VDC mVConfiguration Parameter Name Abr Default LUI Menu UVC configuration parameters OMAbr Default LUI Menu OAD Stroke Time Warranty