Carrier 48/50HJ004-014 specifications Operational Information

Step 6 — Make Final Settings — Be sure to return DIP switch no. 4 back to OFF position to exit Installer Test mode. Assuming the system is to be left in operation after installation is complete, use MODE button to select between HEAT, COOL, or AUTO to provide desired operation of heat- ing, cooling, or both.

The default set points and programmed schedule are

(ONLY ONE PERIOD IS PROGRAMMED):

OCCUPIED 1 = OCCUPIED 2 = 7:00 AM; COOL = 76 F; HEAT = 72 F

DISPLAY WILL READ OC2

UNOCCUPIED 1 = UNOCCUPIED 2 = 5:00 PM; COOL = 85 F; HEAT = 65 F

DISPLAY WILL READ UN2

If programmed schedule is to be used, make sure the HOLD icon is off. The schedule is energized or deenergized by push- ing the HOLD End button.

If fixed temperatures are desired, push HOLD End button to turn on HOLD icon. This will maintain set points, not allowing them to change with programmed schedule.

During unoccupied periods the FAN button may be used to select between AUTO (fan on only with equipment) and FAN (fan on continuously) fan modes. During occupied periods the fan is on continuously.

DEHUMIDIFICATION — Dehumidification is done only during cooling. A dehumidification set point is available to the owner in both occupied and unoccupied times. It can range from 50 to 90 percent relative humidity. When actual humidity is higher than set point, a dehumidification demand exists. In the occupied period, the Light Commercial Thermidistat responds by activating its dehumidify output (DEHUM) turning on the compressor in the Energy$Recycler2 unit; and when a call for cooling exists, energizing the MoistureMi$er™ solenoid in the 48/50HJ unit (if so equipped). The Energy$Recycler2 compres- sor will be started in the Occupied mode even though a call for cooling does not exist; thus dehumidifying the outside air before it enters the building. In the unoccupied period the humidistat will only energize the MoistureMi$er solenoid in the main unit.

However, if the humidity is below the set point in the unoccupied period, a “mini” economizer mode will be initiated bringing in outside air to cool the space as the first stage of cooling, provided the outdoor air thermostat in the Energy$Recycler2 unit is below its set point.

HOLIDAY — A holiday selection is available specifically for times where the building will not be occupied for an extended period. For convenience, one button selects Holiday mode which is indicated by “HOLIDAY” icon on LED display. Holi- day mode also has an automatic hold, meaning that set points are not affected by the programmed schedule. While in Holi- day mode, the system provides temperature and humidity pro- tection for the building in all seasons, but not comfort.

Holiday Set Points — The settings for HEAT, COOL, and DEHUM should have been done in the Configuration mode (Options 9,10, and 11).

OPERATIONAL INFORMATION

Five-Minute Compressor Time Guard® Device — This timer prevents compressor from starting unless it has been off for at least 5 minutes. It can be defeated for 1 cycle by simultaneously pressing FAN and UP buttons simultaneously.

Fifteen-Minute Staging Timer — In multistage heat- ing or cooling, this timer prevents any higher stage from turn- ing on until preceding stage has been on for 15 minutes. This timer is not in effect if temperature difference is greater than 5° F (usually due to a large change in desired temperature).

Three-Minute Minimum On Time — In normal op- eration, when a stage turns on, it will not turn off for a mini- mum of 3 minutes.

Heat/Cool Set Points (Desired Tempera- ture) — A minimum difference of 2° F is enforced between heating and cooling desired temperatures. This is done by allowing one setting to “push” the other to maintain this difference. This difference is adjustable via Configuration Option 14.

Equipment On Indicators — When cooling equip- ment is on, a COOL icon preceded by a small triangle is displayed below cooling set point. While cooling equipment is delayed by the Time Guard timer, triangle will flash. The same is true for HEAT icon and its preceding triangle located under heating set point.

Dehumidify Output On Indicators — The DEHUM icon is on when the dehumidification output is energized.

Auto Changeover — When auto changeover mode is selected, a change from heat to cool (or vice versa) will not oc- cur until an opposite mode demand has existed for 10 minutes. If set point is changed, the 10-minute requirement is deleted.

Power On Check — When AC power is first applied, all segments of display are turned on for a few seconds. Following this, temperature display indicates model/configuration via fol- lowing 2-digit code: CP for commercial product. See Fig. 16.

Error Codes — If Light Commercial Thermidistat cannot properly read room temperature, display will indicate two dashes (--) and all outputs (except fan, if on) will turn off.

E4 — If Light Commercial Thermidistat’s internal memory fails, “E4” will be displayed. Replace Light Commer- cial Thermidistat.

E5 — If Light Commercial Thermidistat cannot properly read humidity, “E5” will be displayed. Replace Light Commercial Thermidistat.

Smart Recovery — With Smart Recovery selected (DIP SW1 is on), transition out of setback begins a fixed time period before selected recovery time and gradually adjusts room tem- perature so desired temperature will be achieved at selected recovery time. The fixed time period is 1.5 hours. It operates in both heating and cooling.

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