Carrier 50HE003-006 Installation Instructions Manual

Contents

36Supply Air Temperature (SAT) SensorThe supply air temperature sensor is a 3 K thermistor located atthe inlet of the indoor fan. (See Fig. 39.) This sensor is factoryinstalled. The operating range of temperature measurement is 0°to 158_F. See Table 6 for sensor temperature/resistance values.Table 6—Supply Air Sensor Temperature/Resistance ValuesTEMPERATURE (F) RESISTANCE (ohms)–58 200,250–40 100,680–22 53,010–4 29,09114 16,59032 9,79550 5,97068 3,74777 3,00086 2,416104 1,597122 1,080140 746158 525176 376185 321194 274212 203230 153248 116257 102266 89284 70302 5517 1/4”DIVIDERBAROMETRICRELIEFCLEANABLEALUMINUMFILTER FILTERHOODFILTERCLIPOUTSIDEAIRC06027Fig. 33 --- Filter InstallationThe temperature sensor looks like an eyelet terminal with wiresrunning to it. The sensor is located in the “crimp end” and issealed from moisture.Outdoor Air Lockout SensorThe Economi$er IV is equipped with an ambient temperaturelockout switch located in the outdoor air stream which is used tolockout the compressors below a 42_F ambient temperature. (SeeFig. 27.)Economi$er IV Control ModesIMPORTANT: The optional EconoMi$er2 does not include acontroller. The EconoMi$er2 is operated by a 4 to 20 mA signalfrom an existing field-supplied controller (such as PremierLink™control). See Fig. 35 for wiring information.Determine the EconoMi$er IV control mode before set up of thecontrol. Some modes of operation may require differentsensors. Refer to Table 7. The EconoMi$er IV is supplied fromthe factory with a supply--air temperature sensor and an outdoor--air temperature sensor. This allows for operation of theEconoMi$er IV with outdoor air dry bulb changeover control.Additional accessories can be added to allow for different types ofchangeover control and operation of the EconoMi$er IV and unit.Table 7—Economi$er IV Sensor UsageAPPLICATIONECONOMI$ER IV WITH OUTDOOR AIRDRY BULB SENSORAccessories RequiredOutdoor AirDry BulbNone. The outdoor air dry bulb sensoris factory installed.DifferentialDry Bulb CRTEMPSN002A00*Single Enthalpy HH57AC078DifferentialEnthalpyHH57AC078andCRENTDIF004A00*CO 2 for DCVControl using aWall-MountedCO 2 Sensor33ZCSENCO2CO 2 for DCVControl using aDuct-MountedCO 2 Sensor33ZCSENCO2†and33ZCASPCO2**OR CRCBDIOX005A00††*CRENTDIF004A00 and CRTEMPSN002A00 accessories are used on manydifferent base units. As such, these kits may contain parts that will not beneeded for installation.† 33ZCSENCO2 is an accessory CO2 sensor.** 33ZCASPCO2 is an accessory aspirator box required for duct-mountedapplications.†† CRCBDIOX005A00 is an accessory that contains both 33ZCSENCO2and 33ZCASPCO2 accessories.Outdoor Dry Bulb ChangeoverThe standard controller is shipped from the factory configured foroutdoor dry bulb changeover control. The outdoor--air andsupply--air temperature sensors are included as standard. For thiscontrol mode, the outdoor temperature is compared to anadjustable set point selected on the control. If the outdoor-airtemperature is above the set point, the EconoMi$er IV will adjustthe outdoor-air dampers to minimum position. If the outdoor airtemperature is below the set point, the position of the outdoor airdampers will be controlled to provide free cooling using outdoorair. When in this mode, the LED next to the free cooling set pointpotentiometer will be on. The changeover temperature set point iscontrolled by the free cooling set point potentiometer located onthe control. (See Fig. 40.) The scale on the potentiometer is A, B,C, and D. See Fig. 41 for the corresponding temperaturechangeover values.Differential Dry Bulb ControlFor differential dry bulb control the standard outdoor dry bulbsensor is used in conjunction with an additional accessory drybulb sensor (part number CRTEMPSN002A00). The accessorysensor must be mounted in the return airstream. (See Fig. 42.)Wiring is provided in the EconoMi$er IV wiring harness. (SeeFig. 33.)In this mode of operation, the outdoor-air temperature iscompared to the return-air temperature and the lower temperatureairstream is used for cooling. When using this mode ofchangeover control, turn the enthalpy setpoint potentiometer fullyclockwise to the D setting. (See Fig. 40.)50HE,HJ