Carrier WeatherExpert 48N2 Controls, Start-up, Operation, Service And Troubleshooting Instructions

Also see for WeatherExpert 48N2: Installation instructions Installation instructions Controls, start-up, operation, service, and troubleshooting Installation instructions

Contents

Carrier WeatherExpert 48N2 Controls, Start-up, Operation, Service And Troubleshooting Instructions Manual pdf 97 page image

97Table 70 — Remote Switch Logic ConfigurationHot Gas Bypass — The ComfortLink control systemsupports the use of an optional minimum load hot gas bypassvalve (MLV) that is directly controlled by the ComfortLinkcontrol system. This provides an additional stage of capacity aswell as low load coil freeze protection. Hot gas bypass is anactive part of the N-Series ComfortLink capacity staging andminimum evaporator load protection functions. It is controlledthough the Minimum Load Valve function. The hot gas bypassoption consists of a solenoid valve with a fixed orifice sized toprovide a nominal 3-ton evaporator load bypass. A hot gas re-frigerant line routes the bypassed hot gas from the dischargeline of circuit A to the suction line of circuit A. An additionalthermistor in the suction line allows the unit control to monitorsuction superheat. When the unit control calls for hot gas by-pass, the hot gas bypasses the evaporator and adds refrigerationload to the compressor circuit to reduce the cooling effect fromCircuit A.The hot gas bypass system is a factory-installed option in-stalled on Circuit A only. This function is enabled at Configu-rationCOOLMLV. When this function is enabled, an ad-ditional stage of cooling capacity is provided by the unit con-trol staging sequences (see Appendix C).Space Temperature Offset — Space Temperature Off-set corresponds to a slider on a T56 sensor that allows the occu-pant to adjust the space temperature by a configured rangeduring an occupied period. This sensor is only applicable tounits that are configured as Multi-Stage SPT control (Configu-rationUNITC.TYP = 4).Space Temperature Offset Sensor (ConfigurationUNITSENSSP.O.S) — This configuration disables the readingof the offset slider.Space Temperature Offset Range (ConfigurationUNITSENSSP.O.R) — This configuration establishesthe range, in degrees F, that the T56 slider can affect SPTOwhen adjusting the slider from the far left (-SP.O.R) to the farright (+SP.O.R). The default is 5° F.Space Temperature Offset Value (TemperaturesAIR.TSPTO) — The Space Temperature Offset Value is the read-ing of the slider potentiometer in the T56 that is resolved todelta degrees based on SP.O.R.TIME CLOCK CONFIGURATIONThis section describes each Time Clock menu item. Notevery point will need to be configured for every unit. Refer tothe Controls Quick Start section for more information on whatset points need to be configured for different applications. TheTime Clock menu items are discussed in the same order thatthey are displayed in the Time Clock table. The Time Clockmenu is shown in Table 71.Hour and Minute (HH.MM) — The hour and minuteof the time clock are displayed in 24-hour, military time. Timecan be adjusted manually by the user.When connected to the CCN, the unit can be configured totransmit time over the network or receive time from a networkdevice. All devices on the CCN should use the same time. Onlyone device on the CCN should broadcast time or problems willoccur.Month of Year (MNTH) — This variable is the currentmonth of the calendar year.Day of Month (DOM) — This variable is the currentday (1 to 31) of the month.Day of Week (DAY) — This variable is the current dayof the week (Monday through Sunday).Year (YEAR) — This variable is the current year (for ex-ample, 2013).Local Time Schedule (SCH.L) — This submenu isused to program the time schedules. There are 8 periods(PER.1 through PER.8). Each time period can be used to setup a local schedule for the unit. Refer to the ProgrammingOperating Schedules section on page 29 for more information.MONDAY IN PERIOD (PER.XDAYSMON) — This vari-able is used to include or remove Monday from the schedule.Each period is assigned an occupied on and off time. If thisvariable is set to YES, then Monday will be included in that peri-od’s occupied time schedule. If this variable is set to NO, thenthe period’s occupied time schedule will not be used on Monday.This variable can be set for Periods 1 through 8.TUESDAY IN PERIOD (PER.XDAYSTUE) — This vari-able is used to include or remove Tuesday from the schedule.Each period is assigned an occupied on and off time. If thisvariable is set to YES, then Tuesday will be included in that pe-riod’s occupied time schedule. If this variable is set to NO, thenthe period’s occupied time schedule will not be used on Tues-day. This variable can be set for Periods 1 through 8.WEDNESDAY IN PERIOD (PER.XDAYSWED) —This variable is used to include or remove Wednesday from theschedule. Each period is assigned an occupied on and off time.If this variable is set to YES, then Wednesday will be includedin that period’s occupied time schedule. If this variable is set toNO, then the period’s occupied time schedule will not be usedon Wednesday. This variable can be set for Periods 1 through 8.THURSDAY IN PERIOD (PER.XDAYSTHU) — Thisvariable is used to include or remove Thursday from the sched-ule. Each period is assigned an occupied on and off time. If thisvariable is set to YES, then Thursday will be included in thatperiod’s occupied time schedule. If this variable is set to NO,then the period’s occupied time schedule will not be used onThursday. This variable can be set for Periods 1 through 8.REMOTESWITCH LOGICCONFIGURATION(RMI.L)SWITCHSTATUSREMOTE INPUT STATE(REMT)REMOTE SWITCH CONFIGURATION (RM.CF)0 1 2 3No Remote Switch Occ-Unocc Switch Start/Stop OverrideOPEN OPEN OFF (0) xxxxx Unoccupied Start No OverrideCLOSED ON (1) xxxxx Occupied Stop OverrideCLOSED OPEN ON (0) xxxxx Occupied Stop OverrideCLOSED OFF (1) xxxxx Unoccupied Start No OverrideITEM EXPANSION RANGE UNITS CCNPOINTSP.O.S Space TempOffset SensorEnable/DisableSPTOSENSSP.O.R Space TempOffset Range1 - 10 SPTO_RNGSPTO Space TemperatureOffset+- SP.O.R ^F SPTO