Carrier 48GP (N) 024-060 Installation And Operating Instructions Manual

Contents

value. If circuit R to G is open (0–v.) for super dehumidifymode, the motor delivers reduced airflow to maximize thehumidity removal of the system while minimizing overcooling.e. ELECTRIC HEATING MODE(1.) Thermostat closes circuit R to W/W1, or W2—The unitdelivers the selected electric heat airflow. There are no onor off delays.f. HEAT PUMP HEATING MODE (50JZ only)(1.) Thermostat closes circuits R to G and R to Y/Y2—The unitdelivers selected heat pump heating airflow.g. HEAT PUMP HEATING WITH AUXILIARYELECTRIC HEAT (50JZ only)(1.) Thermostat closes circuits R to G, R to Y/Y2 and R toW/W1 or W2 (and R to O in the case of defrost).In the event that electric heating is called for by the thermostatwhile the heat pump is also operating in either heating ordefrost modes, the motor will modify its airflow output, ifnecessary, to provide an airflow which is defined as safe for theoperation of the electric heater during heat pump operation.That airflow is the greater of the heat pump heating airflow andthe electric heater only airflow.h. HEATING MODE—SUPER COMFORT HEAT OPERA-TIONNOTE: The indoor control used, such as a Thermidistat™, mustbe capable of providing Super Comfort Heat operation mode andcontrol must be configured as outlined in its installation instruc-tions. The system must be installed with appropriate outdoortemperature sensor. Consult indoor control literature to determineif control is capable and for configuration instructions. Consultindoor control instructions and sensor instructions for sensorinstallation details.If the outdoor temperature is in the range of 12° to 40° F, theThermidistat™ closes circuit R to Y/Y2 and opens circuit R to G.If circuit R to G is closed (24-v.), the motor will deliver airflow atthe full heating requested value. If circuit R to G is open (0-v.) formaximum heating comfort, the motor delivers reduced airflow tomaximize the temperature and minimize the draft effect of theheated air leaving the unit.ICM FIOP START-UPICM General Start UpCHECKING AND ADJUSTING REFRIGERANT CHARGEThe refrigerant system is fully charged with Puron® (R-410A)refrigerant, and is tested and factory sealed.NOTE: Adjustment of the refrigerant charge is not requiredUNLESS the unit is suspected of not having the proper R-410Acharge.The charging label and the tables shown refer to system tempera-tures and pressures. The temperatures and pressures are calculatedat rated airflow. When charging unit, set to rated airflow. Arefrigerant charging chart label is attached to the outside of thecompressor access door. The chart includes the required suctionline temperature at given suction line pressures and outdoorambients. An accurate superheat, thermocouple- or thermistor-typethermometer, and gage manifold are required when using thesuperheat charging method for evaluating the unit charge. Do notuse mercury or small dial-type thermometers because they arenot adequate for this type of measurementIMPORTANT: When evaluating the refrigerant charge, an indi-cated adjustment to the specified factory charge must always bevery minimal. If a substantial adjustment is indicated, an abnormalcondition exists somewhere in the cooling system, such as insuf-ficient airflow across either one or both coils.Step 1—48GP Start-Up (ICM FIOP)CHECKING COOLING CONTROL OPERATION-Start andcheck the unit for proper cooling control operation as follows:(1.) Place room thermostat SYSTEM switch in OFF position.Observe that blower motor starts when FAN switch isplaced in ON position and shuts down when FAN switchis placed in AUTO position. Note fan delay time settingselected on the Easy Select™ board. (See Easy SelectSection.)(2.) Place SYSTEM switch in COOL position and FAN switchin AUTO position. Set cooling control below room tem-perature. Observe that compressor, condenser fan, andevaporator blower motors start. Observe that cooling cycleshuts down when control setting is satisfied. The evapo-rator fan will continue to run for the time setting selectedon Easy Select™ board. (See Easy Select Section.)(3.) When using an auto-changeover room thermostat, placeboth SYSTEM and FAN switches in AUTO position.Observe that unit operates in heating mode when tempera-ture control is set to “call for heating” (above roomtemperature) and operates in cooling mode when tempera-ture control is set to “call for cooling” (below roomtemperature).AIRFLOW AND TEMPERATURE RISE-The heating section foreach size unit is designed and approved for heating operationwithin the temperature rise range stamped on the unit rating plate.Table 15 shows the approved temperature rise range for eachheating input, and the air delivery (CFM) at various temperaturerise ranges.The heating operation airflow must produce a temperature rise thatfalls with in the approved range.Refer to Indoor Airflow and Airflow Tables on the followingpages to adjust heating airflow when required.CHECK HEATING CONTROL-Start and check the unit forproper heating control operation as follows. (see furnace lightinginstructions located inside burner or blower access panel.):(1.) Place room thermostat SYSTEM switch in the HEATposition and the FAN switch in the AUTO position.(2.) Set the heating temperature control of the thermostat aboveroom temperature.(3.) The induced-draft motor will start.(4.) After a call for heating, the main burner should light within 5 sec. If the burners still do not light, this sequence isrepeated. If the burners do not light within 15 minutes fromthe initial call for heat, there is a lockout. To reset thelockout control, break the 24-v. power to W.(5.) The indoor fan will turn on 45 sec after the flame has beenestablished. The indoor fan will turn off according to timedelay selected on the Easy Select™ board (See Easy SelectSection) after the thermostat has been satisfied.Step 2—48JZ Start-Up (ICM FIOP)Also refer to the Thermidistat™ instructions for start up andcheck out of the system.(1.) FAN OPERATION—The fan button on Thermidistat™ switches fan iconbetween AUTO and ON. While ON is displayed, outputwill be on, turning fan on. Allow up to 10 sec. after buttonis pressed for fan to turn on and off. the fan will continueto run for the time setting selected on the Easy Select™board after AUTO icon is displayed.10