Carrier COBRA 48/50HJ004-014 - Manual (Page 34)

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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.