Carrier 48TCA04---A12 Service And Maintenance Instructions

76S SPT reading is available and < (OHSP + STO).S If it is unoccupied and the SPT < (UHSP -- UnoccupiedHeating Deadband). The indoor fan will be turn on by thestaging algorithm.When all of the above conditions are met, the SHSR iscalculated and up to 3 stages of heat will turned on and offto satisfy to maintain the SAT = SHSR. If any of theabove conditions are not met, the SHSR is set to itsminimum value of 35_F.The Staged Heat Submaster Reference (SHSR) iscalculated as follows:SHSR = Heating PID function on (error) where error =(OHSP + STO) -- Space TemperatureThe Maximum SHSR is determined by the SATHIconfiguration. If the supply--air temperature exceeds theSATHI configuration value, then the heat stages will turnoff. Heat staging will resume after a delay to allow thesupply--air temperature to drop below the SATHI value.The maximum number of stages available is dependent onthe type of heat and the number of stages programmed inthe CONFIG and SERVICE configuration tables. Stagingwill occur as follows for gas electric units, Carrier heatpumps with a defrost board, or cooling units with electricheat:For Heating PID STAGES = 2HEAT STAGES = 1 (50% capacity) -- energize HS1.HEAT STAGES = 2 (100% capacity) -- energize HS2.For Heating PID STAGES = 3 and AUXOUT = HS3HEAT STAGES = 1 (33% capacity if) -- energize HS1HEAT STAGES = 2 (66% capacity) -- energize HS2HEAT STAGES = 3 (100% capacity) -- energize HS3Staging will occur as follows For heat pump units withAUXOUT configured as reversing valve:For Heating PID STAGES = 2 and AUXOUT = ReversingValve Heat (the H3_EX_RV output will stay energizeduntil there is a cool demand) HEAT STAGES = 1 (50%capacity) shall energize CMP1, CMP2, RVS.HEAT STAGES = 2 (100% capacity) shall energize HS1and HS2.Heating PID STAGES = 3 and AUXOUT = ReversingValve Heat (the H3_EX_RV output will stay energizeduntil there is a cool demand)HEAT STAGES = 1 (33% capacity if) shall energizeCMP1, CMP2, RVSHEAT STAGES = 2 (66% capacity) shall energize HS1HEAT STAGES = 3 (100% capacity) shall energize HS2If AUXOUT is configured for Reversing Valve Cool, thenthe H3_EX_RV contact will be deenergized when there isa demand for heating. The heat stages will be cycled totemper the SAT so that it will be between the SPT and theSPT + 10_F (SPT < SAT < (SPT + 10_F)) if:S the number of heat stages calculated is zeroS the OAT < 55_FS an IAQ sensor is installedS the IAQ Minimum Damper Position > minimum damperpositionS and the SAT < SPT --10_F.There is also a SAT tempering routine that will act as SATlow limit safety to prevent the SAT from becoming toocold should the economizer fail to close. One stage ofheating will be energized if it is not in the Cooling or FreeCooling mode and the OAT is below 55_F and the SAT isbelow 40_F. It will deenergize when the SAT > (SPT +10_F).Indoor Air Quality — If the optional indoor air quality(IAQI) sensor is installed, the PremierLink controller willmaintain indoor air quality within the space at the userconfigured differential setpoint (IAQD) in the CONFIGconfiguration table. The setpoint is the difference betweenthe IAQI and an optional outdoor air quality sensor(OAQ). If the OAQ is not present then a fixed value of400 ppm is used. The actual space IAQ setpoint (IAQS) iscalculated as follows:IAQS = IAQD + OAQ (OAQ = 400 ppm if not present)As air quality within the space changes, the minimumposition of the economizer damper will be changed alsothus allowing more or less outdoor air into the spacedepending on the relationship of the IAQI to the IAQS.The IAQ algorithm runs every 30 seconds and calculatesIAQ minimum position value using a PID loop on theIAQI deviation from the IAQS. The IAQ minimumposition is then compared against the user configuredminimum position (MDP) and the greatest value becomesthe final minimum damper position (IQMP). If thecalculated IAQ minimum position is greater than the IAQmaximum damper position (IAQMAXP) decision in theSERVICE configuration table, then it will be clamped toIAQMAXP value.If IAQ is configured for low priority, the positioning ofthe economizer damper can be overridden by comfortrequirements. If the SPT > OCSP + 2.5 or the SPT <OHSP -- 2.5 then IAQ minimum position becomes 0 andthe IQMP = MDP. The IAQ mode will resume when theSPT ≤ OCSP + 1.0 and SPT ≥ OHSP -- 1.0.If IAQ is configured for high priority and the OAT < 55_Fand the SAT < (SPT -- 10_F), the algorithm will enable theheat stages to maintain the SAT between the SPT and theSPT + 10_F.IAQ Pre--Occupancy Purge — This function is designed topurge the space of airborne contaminants that may haveaccumulated 2 hours prior to the beginning of the nextoccupied period. The maximum damper position that willbe used is temperature compensated for cold whetherconditions and can be pre--empted by TemperatureCompensated Start function. For pre--occupancy to occur,the following conditions must be met:S IAQ Pre--Occupancy Purge option is enabled in theCONFIG configuration tableS Unit is in the unoccupied stateS Current Time is valid48TC