Carrier 50PG20 User Manual

44
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 Lag
Factor (Operating 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 chang-
ing at a rate greater than 0.3° F per minute.
The control uses two methods to remove a stage of heating.
The first method will remove 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 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 apply when adding stages
(Configuration
→ HEAT → H.INC) or removing stages
(Configuration
→ HEAT → H.DEC). Heat stage minimum
on-time (Configuration → HEAT → MRT.H) and minimum
off-time (Configuration
→ HEAT → MOT.H) also apply.
SUPPLY-AIR TEMPERATURE (SAT) SENSOR — 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 sen-
sor 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.
Electric Heat (50PG Units) — For 50PG units with
factory-installed electric heat, the heat type configuration
Configuration
→ HEAT → HT.TY will be factory set to a
value of 2 and the number of heat stages configuration
Configuration
→ HEAT → N.HTR will be factory set to match
the installed heater. If electric heat is installed in the field, the
value of HT.TY must be changed.
Heat will not operate if the outdoor temperature is
greater than the value configured for the heat lockout tempera-
ture, Configuration
→ HEAT → HT.LO. Minimum on-time,
Configuration
→ HEAT → MRT.H, and minimum off-time,
Configuration
→ HEAT → MOT.H, timeguards apply to both
stages of heating. Factory default values are 2 minutes On and
2 minutes Off.
If the indoor fan control is configured to cycle with the heat-
ing demand (Configuration
→ UNIT → OC.FN = No) the
fan will stop after a configured delay (Configuration
→ HEAT → FOD.E). The factory default value is 30 seconds.
THERMOSTAT CONTROL — The first stage of electric
heat (HT.1) will follow the W1 input and the second stage
(HT.2) of heat will follow the W2 input. During auto fan, the
indoor fan will follow the HT.1 output. During continuous fan,
the indoor fan will follow the G input.
If the user has selected Adaptive (see Cooling section) for
thermostat mode, the algorithm will follow the configurable
delays for adding and removing stages. When adding addition-
al heat stages, the delay is measured from when the last stage
was added (Configuration
→ HEAT → H.INC). When remov-
ing stages, the delay is measured from when the last stage was
removed (Configuration
→ HEAT → H.DEC). Therefore, if
W1 and W2 turn on simultaneously, the second stage will turn
on after a H.INC delay.
NOTE: If the mode is not Adaptive, then there are no delays
for adding and removing stages.
SPACE SENSOR CONTROL — During Space Sensor con-
trol, the electronic control uses information from the space
sensor to determine the number of heat stages. Once the num-
ber of stages needed for heating is determined, either HT.1 or
HT.1 and HT.2 outputs will be turned on. See Space Sensor
Control section for gas heat units for more information.
NOTE: The jumper wire in the installer’s packer must be con-
nected between R and W1 when using a T-55, T-56, or T-58
device. See Major System Components section.
SUPPLY-AIR TEMPERATURE (SAT) SENSOR — The SAT
Heat Sensing Configuration affects the SAT value displayed.
SAT Heat Sensing (SAT.H) 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 sen-
sor 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.
Economizer — If an economizer is installed, then
Economizer Installed configuration (Configuration
→
UNIT → EC.EN) should be set to YES. The economizer is
controlled by the economizer output signal (Outputs
→
ECON → EC.CP) on the ECB control. If the indoor fan is off or
the building is unoccupied, the economizer position is zero. If
in Occupied mode and the unit is heating or cooling and the
economizer cannot provide free cooling, the economizer
position is the configured economizer minimum position
(Configuration
→ ECON → EC.MN) or the position specified
by the IAQ algorithm. If in Unoccupied mode, the position is
0% open.
The economizer will be allowed to help with cooling if the
outdoor-air temperature (Tem pera ture
→ AIR.T → OAT) is less
than the configured economizer high temperature lockout
(Setpoints
→ EH.LO) and greater than the configured econo-
mizer low temperature lockout (Setpoints
→ EL.LO). If an
enthalpy sensor is installed, the outdoor temperature must be
below the economizer high temperature lockout and the
enthalpy (Inputs
→ GEN.I → ENTH) must be LOW. For cool-
ing, the economizer position can vary between the con-
figured economizer minimum position (Configuration
→
ECON → EC.MN) and the economizer maximum cooling
position (Configuration
→ ECON → EC.MX).
THERMOSTAT CONTROL — If the unit is in cooling,
operating under thermostat control, Y1 = ON, and the econo-
mizer is available for cooling, the economizer will control the
supply-air temperature to the low cool set point
(Setpoints
→ LCSP). When Y2 = ON, the economizer will con-
trol the supply-air temperature to high cool set point
(Setpoints
→ HCSP).

Carrier 50PG20 Specifications

General

Brand	Carrier
Model	50PG20
Category	Air Conditioner
Language	English