American Standard UV05 manual Troubleshooting Carbon Dioxide CO2 Sensors, Humidity versus voltage

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Diagnostics and Service

Table 24: Humidity versus voltage.

RH (%)	VDC (mV)	RH (%)	VDC (mV)
10	1330	55	2480
15	1475	60	2600
20	1610	65	2730
25	1740	70	2860
30	1870	75	2980
35	1995	80	3115
40	2120	85	3250
45	2235	90	3390
50	2360	95	3530

Troubleshooting Carbon Dioxide (CO2) Sensors

The UVC is configured to use a 0–2000 PPM, 0–10 VDC, single beam absorption infrared gas sensor. Each sensor is calibrated according to the table shown.

Use the following procedure to troubleshoot a suspect sensor.

1Disconnect the sensors output voltage lead from the UVC analog input (xAI-3).

2Using some other calibrated CO2 sensing device, take a CO2 reading at the sensor location.

3Use the CO2 reading from Step 2 to determine the expected sensor voltage from Table 25.

4Using a calibrated multi-meter, measure the actual voltage across the lead removed from xAI-3 and ground.

5Compare the expected voltage to the actual voltage.

6If the actual voltage value deviates substantially (more than 10%) from the expected voltage, replace the sensor.

In the unlikely event that the CO2 sensor requires calibration, consult the factory for information on obtaining calibration equipment and instructions.

Table 25: CO2 versus voltage table

CO2 (PPM)	VDC (V)	CO2 (PPM)	VDC (V)
300	1.5	1200	6.0
400	2.0	1300	6.5
500	2.5	1400	7.0
600	3.0	1500	7.5
700	3.5	1600	8.0
800	4.0	1700	8.5
900	4.5	1800	9.0
1000	5.0	1900	9.5

46	McQuay OM 751

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Contents Group Applied Systems DX Cooling Only Software Model UV05Date November Getting Started UVC Configuration ParametersIntroduction Description of OperationAccessory-specific installation literature Model-specific unit ventilator installation literatureDescription Manual # Extreme temperature can damage system components Software program literatureAcronyms and abbreviations Acronyms/AbbreviationsDescription Acronym Abr OCS Keypad Functions Using the Keypad/DisplayDisplay Format Security LevelsFAN Key Mode KeyON/STOP Key and LED Arrow KeysMenu Reference Using the Keypad/DisplayViewing Actual Indoor Air Temperature IAT Changing Set PointsAbr Description Default RW1Chlo Description of Operation State ProgrammingComplete UVC-state diagram UVC Unit ModesNormal UVC modes State names OFF Mode StateUVC state names and numbers DecimalNight Purge Mode State Fan Only Mode State aFull Heat State State Emergency Heat Mode Super StateCant Heat State State D Heat Mode Super State Auto ModeHeat State State Low Limit State State E Cool Mode Super StateCant Heat State State B Cool mode super state diagram Econ State StateEcon Mech State State Mech State StateLow Limit State State F Special Purpose Unit ModesDischarge Air DA Heat State State Cant Cool State State CPurge Mode Pressurize ModeDepressurize Mode Shutdown ModeNormal UVC mode priority Unit Mode PrioritySpecial purpose UVC unit mode priority Priority resultStandby Mode Occupied ModeUnoccupied Mode Occupancy mode priorityAdditional Occupancy Features Networked Set Point Capability Space Temperature Set PointsNetworked Space Temperature Sensor Capability Networked Set Point Offset CapabilityRemote Wall-Mounted Sensor with +/-3F Adjustment optional Effective Set Point CalculationsExample a Example B Given Set point calculation examplesEffective set point calculations PI loop list Discharge Air Temperature ControlProportional Integral PI Control Loops PI loopsPI Control Parameters Proportional BandIntegral Time Indoor Air Fan OperationOccupied, Standby, and Bypass Operation Outdoor Air Damper Operation Economizer Economizer enableOA temp sensor Space humidity CO2 Demand Controlled Ventilation optional Networked Space Humidity Sensor CapabilityNetworked Outdoor Humidity Sensor Capability Networked Space CO2 Sensor CapabilityCompressor Envelope Compressor OperationAshrae Cycle Compressor Cooling LockoutFloating-Point Actuator Auto-Zero, Overdrive and Sync Compressor Minimum On and Off TimersCompressor Start Delay Outdoor Air Fan OperationVentilation Lockout Input Signal Unoccupied Input SignalRemote Shutdown Input Signal External Binary InputsFault Signal Exhaust Interlock Input SignalLights On/Off Signal External Binary OutputsAuxiliary heat start/stop calculation Exhaust Fan ON/OFF SignalAuxiliary Heat Signal Start/Stop CalculationInputs and outputs, software model 05-DX cooling only Expansion boardAlarm and fault code summary Alarm and Fault MonitoringPriority Fault description Reset Keypad Space Temp Sensor Failure F0 DX Pressure Fault F1Compressor Envelope Fault F2 Discharge Air DX Cooling Low Limit Indication F3Outdoor Temp Sensor Failure F6 Condensate Overflow Indication optional F4Space Coil DX Temp Sensor Failure F5 Discharge Air Temp Sensor Failure F7Troubleshooting Temperature Sensors Troubleshooting Humidity Sensors Temperature versus resistanceCO2 versus voltage table Troubleshooting Carbon Dioxide CO2 SensorsHumidity versus voltage RH % VDC mVUVC configuration parameters OM Configuration Parameter Name Abr Default LUI MenuAbr Default LUI Menu OAD Stroke Time Warranty