Carrier 48PG03-16 Controls, Start-Up, Operation, Service And Troubleshooting Instructions page 65

ELECTRICAL
OPTIONS PANEL
OUTDOOR AIR
SCREEN
(HIDDEN)
BASEPAN CONNECTIONS
The unit tries to maintain the space temperature at the Occupied
Heat Set Point (Setpoints→OHSP) or the Unoccupied Heat Set
Point (Setpoints→UHSP). See the Occupancy Determination
section for factors that affect the Occupied status (Run
Status→VIEW→OCC).
Heating
Modes→HEAT→SPT→DMD.H) is equal to the occupied or
unoccupied set point minus the Space Temperature (Operating
Modes→HEAT→SPT→SPT).
DMD.H = setpoint – SPT
Two methods are used to add and remove stages of heating for
units with more than one heat stage. The first method causes the
unit to operate around its steady-state number of stages.
For example, if the correct number of stages is between 0 and 1,
this method will cause the first stage to cycle. If the correct
number of stages is between 1 and 2, this method will cause the
second stage to cycle. The second method causes the unit to find
the steady-state number of stages. Details of these methods are
provided below.
The control uses two methods to add a stage of heating. The first
method will add a stage of heating when the Heating Demand
(Operating Modes→HEAT→SPT→ DMD.H) plus the change
in heat demand (Operating Modes→HEAT→SPT→TRD.H)
times the Heat Thermal
Modes→HEAT→SPT→H.LAG) is greater than the SPT Heat
Demand (+) Level (Operating Modes→ HEAT→SPT→HT.PD).
DMD.H + TRD.H * H.LAG > HT.PD
The second method will add a stage of heating when Heat
Demand is greater than the SPT Heat Demand (+) Level plus 0.5°
F (DMD.H > HT.PD + 0.5) and the heat demand is changing at a
rate greater than 0.3° F per minute.
CONTROL BOX
AND
COMPRESSOR
ACCESS PANEL
Fig. 8 --- Panel and Filter Locations (48PG03- -07 Unit Shown)
Demand (Operating
Lag Factor (Operating
FILTER ACCESS DOOR
The control uses two methods to remove a stage of heating. The
first method will remove a stage of heating when the
Demand (Operating Modes→HEAT→SPT→ DMD.H) plus the
change in heat
Modes→HEAT→SPT→TRD.H) times the Heat Thermal Lag
Factor (Operating Modes→HEAT→SPT→H.LAG) is less than
the SPT Heat Demand (–) Level (Operating Modes→
HEAT→SPT→HT.ND).
DMD.H + change TRD.H * H.LAG < HT.ND
The second method will remove a stage of heating when Heat
Demand is less than the SPT Heat Demand (–) Level minus 0.5°F
(DMD.H < HL.ND – 0.5) and the heat demand is changing at a
rate less than 0.3° F per minute.
Configurable delays also
(Configuration→HEAT→H.INC)
(Configuration→HEAT→H.DEC).
on-time (Configuration→HEAT→MRT.H)
off-time (Configuration→HEAT→MOT.H) also apply.
Supply- -Air Temperature Sensor (SAT)
The SAT Heat Sensing Configuration affects the SAT value
displayed. The configuration is accessible via the Scrolling
Marquee at Configuration→Unit→SAT.H.
Configuration →HEAT →SAT.H = DSBL
When SAT.H = DSBL, the SAT value on the Scrolling Marquee
and CCN tables will be forced to zero when heat outputs come
ON and for 5 minutes after. The default SAT sensor location is at
the fan inlet, upstream of the heat section.
Configuration →HEAT →SAT.H = ENBL
When SAT.H = ENBL, the supply-air temperature measured by
the SAT sensor is displayed at the scrolling marquee and the CCN
tables during heating mode. This setting should only be used if
the original SAT sensor is replaced by an accessory SAT sensor
located in the supply duct, downstream of the heat section.
65
INDOOR MOTOR
ACCESS DOOR
CONDENSER COIL
ACCESS PANEL
GAS SECTION
ACCESS
C07002
Heating
demand (Operating
apply when adding stages
or removing stages
Heat stage minimum
and minimum