Carrier SEER 48ES Installation Instructions Manual

Also see for 48ES: Owner's information manual Installation instructions

Contents

Carrier SEER 48ES Installation Instructions Manual Manual pdf 19 page image

19Limit SwitchesNormally closed limit switch (LS) completes the control circuit.Should the leaving--air temperature rise above the maximumallowable temperature, the limit switch opens and the controlcircuit “breaks.” Any interruption in the control circuit instantlycloses the gas valve and stops gas flow to the burners and pilot.The blower motor continues to run until LS resets.When the air temperature at the limit switch drops to thelow--temperature setting of the limit switch, the switch closes andcompletes the control circuit. The direct--spark ignition systemcycles and the unit returns to normal heating operation.Table 5 – LED IndicationsERROR CODE LED INDICATIONNormal Operation 2 OnHardware Failure OffLimit Switch Fault 2 FlashesFlame Sense Fault 3 FlashesFour Consecutive Limit Switch Faults 4 FlashesIgnition Lockout Fault 5 FlashesInduced--Draft Motor Fault 6 FlashesRollout Switch Fault 7 FlashesInternal Control Fault 8 FlashesTemporary Lock--Out 1 hr auto reset1 9 FlashesNOTES:1.This code indicates an internal processor fault that will reset itself in onehr. Fault can be caused by stray RF signals in the structure or nearby. Thisis a UL requirement.2. LED indicates acceptable operation. Do not change ignition controlboard.3. When W1 is energized the burners will remain on for a minimum of 60sec.4. If more than one error mode exists they will be displayed on the LED insequence.Rollout SwitchThe function of the rollout switch is to close the main gas valve inthe event of flame rollout. The switch is located above the mainburners. When the temperature at the rollout switch reaches themaximum allowable temperature, the control circuit trips, closingthe gas valve and stopping gas flow to the burners. The indoor(evaporator) fan motor (IFM) and induced draft motor continue torun until switch is reset. The IGC LED will display FAULT CODE7.Step 3 — Start--up Cooling and Make Adjust-mentsComplete the required procedures given in the Pre--Start--Upsection before starting the unit. Do not jumper any safety deviceswhen operating the unit. Do not operate the compressor when theoutdoor temperature is below 40°F (4.4°C) (unless accessorylow--ambient kit is installed). Do not rapid--cycle the compressor.Allow 5 minutes between on cycles to prevent compressor damage.Checking Cooling Control OperationStart and check the unit for proper cooling control operation asfollows: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 switch isplaced in AUTO position.2. Place SYSTEM switch in COOL position and FAN switchin AUTO position. Set cooling control below roomtemperature. Observe that compressor, condenser fan, andevaporator blower motors start. Observe that cooling cycleshuts down when control setting is satisfied. The evaporatorfan will continue to run for 60 sec.3. When using an auto--changeover room thermostat, placeboth SYSTEM and FAN switches in AUTO positions.Observe that unit operates in Heating mode whentemperature control is set to call for heating (above roomtemperature) and operates in Cooling mode whentemperature control is set to call for cooling (below roomtemperature).IMPORTANT: Three--phase, scroll compressors are directionoriented. Unit must be checked to ensure proper compressor3--phase power lead orientation. If not corrected within 5 minutes,the internal protector will shut off the compressor. The 3--phasepower leads to the unit must be reversed to correct rotation. Whenturning backwards, the difference between compressor suction anddischarge pressures will be minimal.Checking and Adjusting Refrigerant ChargeThe refrigerant system is fully charged with PuronR (R--410A)refrigerant and is tested and factory sealed. Allow system to operatea minimum of 15 minutes before checking or adjusting charge.NOTE: Adjustment of the refrigerant charge is not required unlessthe unit is suspected of not having the proper PuronR (R--410A)charge.The charging label and the tables shown refer to systemtemperatures and pressures in cooling mode only. A refrigerantcharging label is attached to the outside of the service access door.The chart includes the required liquid line temperature at givendischarge line pressures and outdoor ambient temperatures.An accurate thermocouple-- or thermistor--type thermometer, and agauge manifold are required when using the subcooling chargingmethod for evaluating the unit charge. Do not use mercury or smalldial--type thermometers because they are not adequate for this typeof measurement.UNIT DAMAGE HAZARDFailure to follow this caution may result in unit damage.When evaluating the refrigerant charge, an indicatedadjustment to the specified factory charge must always bevery minimal. If a substantial adjustment is indicated, anabnormal condition exists somewhere in the cooling system,such as insufficient airflow across either coil or both coils.! CAUTIONProceed as follows:1. Remove caps from low-- and high--pressure service fittings.2. Using hoses with valve core depressors, attach low-- andhigh--pressure gauge hoses to low-- and high--pressureservice fittings, respectively.3. Start unit in Cooling Mode and let unit run until systempressures stabilize.4. Measure and record the following:a. Outdoor ambient--air temperature (°F (°C) db).b. Liquid line temperature (°F (°C).c. Discharge (high--side) pressure (psig).d. Suction (low--side) pressure (psig) (for reference only).5. Using “Cooling Charging Charts,” compare outdoor--airtemperature(°F (°C) db) with the discharge line pressure(psig) to determine desired system operating liquid linetemperature (See Table 7).6. Compare actual liquid line temperature with desired liquidline temperature. Using a tolerance of ± 2°F (±1.1°C), addrefrigerant if actual temperature is more than 2°F (1.1°C)higher than proper liquid line temperature, or removerefrigerant if actual temperature is more than 2°F (1.1°C)lower than required liquid line temperature.48ES