Carrier 48AJ Operating And Service Manual

Also see for 48AJ: Installation, Start-Up and Service Instructions Installation instructions Operation and service guide Started guide

68TEMPERATURE COMPENSATED START LOGIC — Thefollowing conditions must be met:• Unit is in unoccupied state.• Next occupied time is valid.• Current time of day is valid.• Valid space temperature reading is available (sensor orDAV-Linkage).The algorithm will calculate a Start Bias time in minutes us-ing the following equations:If (space temperature > occupied cooling set point)Start Bias Time = (space temperature – occupied cooling setpoint)* TCS.CIf (space temperature < occupied heating set point)Start Bias Time = (occupied heating set point – spacetemperature)*TCS.HWhen the Start Bias Time is greater than zero the algorithmwill subtract it from the next occupied time to calculate the newstart time. When the new start time is reached, the TemperatureCompensated Start mode is set (Operating Modes→MODE→T.C.ST), the fan is started and the unit controlled as in an occu-pied state. Once set, Temperature Compensated mode will stayon until the unit goes into the Occupied mode. The Start BiasTime will be written into the CCN Linkage Equipment Table ifthe unit is controlled in DAV mode. If the Unoccupied Econo-mizer Free Cool mode is active (Operating Modes→HVAC =“UNOCC FREE COOL”) when temperature compensatedstart begins, the Unoccupied Free Cool mode will be stopped.Carrier Comfort Network® (CCN) — It is possibleto configure the ComfortLink™ control to participate as an ele-ment of the Carrier Comfort Network (CCN) directly from thelocal display. This section will deal with explaining the variousprogrammable options which are found under the CCN sub-menu in the Configuration mode.The major configurations for CCN programming are locat-ed in the local displays at Configuration→CCN. See Table 80.CCN Address (CCNA) — This configuration is the CCN ad-dress the rooftop is assigned.CCN Bus Number (CCNB) — This configuration is the CCNbus the rooftop is assigned.CCN Baud Rate (BAUD) — This configuration is the CCNbaud rate.CCN Time/Date Broadcast (TM.DT) — If this configurationis set to ON, the control will periodically send the time and dateout onto the CCN bus once a minute. If this device is on a CCNnetwork then it will be important to make sure that only onedevice on the bus has this configuration set to ON. If more thanone time broadcaster is present, problems with the time willoccur.NOTE: Only the time and date broadcaster can performdaylight savings time adjustments. Even if the rooftop is standalone, the user may want to set this to ON to accomplish thedaylight/savings function.CCN OAT Broadcast (OAT.B) — If this configuration is setto ON, the control will periodically broadcast its outside-airtemperature at a rate of once every 30 minutes.CCN OARH Broadcast (ORH.B) — If this configuration isset to ON, the control will periodically broadcast its outside airrelative humidity at a rate of once every 30 minutes.CCN OAQ Broadcast (OAQ.B) — If this configuration is setto ON, the control will periodically broadcast its outside airquality reading at a rate of once every 30 minutes.Global Schedule Broadcast (G.S.B) — If this configuration isset to ON and the schedule number (SCH.N) is between 65 and99, then the control will broadcast the internal time scheduleonce every 2 minutes.CCN Broadcast Acknowledger (B.ACK) — If this configu-ration is set to ON, then when any broadcasting is done on thebus, this device will respond to and acknowledge. Only one de-vice per bus can be configured for this option.Schedule Number (SCH.N) — This configuration determineswhat schedule the control may follow.SCH.N = 0 The control is always occupied.SCH.N = 1 The control follows its internal time sched-ules. The user may enter any numberbetween 1 and 64 but it will be overwrittento “1” by the control as it only has oneinternal schedule.SCH.N = 65-99 The control is either set up to receive to abroadcasted time schedule set to thisnumber or the control is set up to broadcastits internal time schedule (G.S.B) to thenetwork and this is the global schedulenumber it is broadcasting. If this is the case,then the control still follows its internal timeschedules.Accept Global Holidays? (HOL.T) — If a device is broad-casting the time on the bus, it is possible to accept the time yetnot accept the global holiday from the broadcast message.Override Time Limit (O.T.L) — This configuration allowsthe user to decide how long an override occurs when it is initi-ated. The override may be configured from 1 to 4 hours. If thetime is set to 0, the override function will become disabled.Timed Override Hours (OV.EX) — This displays the currentnumber of hours left in an override. It is possible to cancel anoverride in progress by writing “0” to this variable, therebyremoving the override time left.Table 80 — CCN ConfigurationITEM EXPANSION RANGE UNITS POINT DEFAULTCCN CCN CONFIGURATIONCCNA CCN Address 1 - 239 CCNADD 1CCNB CCN Bus Number 0 - 239 CCNBUS 0BAUD CCN Baud Rate 1 - 5 CCNBAUDD 3BROD CCN BROADCST DEFINITIONSTM.DT CCN Time/Date Broadcast ON/OFF CCNBC OnOAT.B CCN OAT Broadcast ON/OFF OATBC OffORH.B CCN OARH Broadcast ON/OFF OARHBC OffOAQ.B CCN OAQ Broadcast ON/OFF OAQBC OffG.S.B Global Schedule Broadcst ON/OFF GSBC OffB.ACK CCN Broadcast Ack'er ON/OFF CCNBCACK OffSC.OV CCN SCHEDULES-OVERRIDESSCH.N Schedule Number 0 - 99 SCHEDNUM 1HOL.T Accept Global Holidays? YES/NO HOLIDAYT NoO.T.L. Override Time Limit 0 - 4 HRS OTL 1OV.EX Timed Override Hours 0 - 4 HRS OVR_EXT 0SPT.O SPT Override Enabled ? YES/NO SPT_OVER YesT58.O T58 Override Enabled ? YES/NO T58_OVER YesGL.OV Global Sched. Override ? YES/NO GLBLOVER No