Hvac Operation Disabled (Hv.dn); General Operation; Temperature Setpoint Determination; Timed Override In Effect (T.ovr) - Carrier 48/50PG C03-14 Operation And Service Manual

HVAC Operation Disabled (HV.DN)

Allow disabling of HVAC mode. This is only available on a
network connection and shows if the unit has been forced into the
disabled status.
Cool Setpoint In Effect (EFF.C)
This shows the actual setpoint that is being used for control during
cooling mode. If a 0 is displayed, then space sensor control is not
being used and the unit is being controlled by a thermostat.
Heat Setpoint In Effect (EFF.H)
This shows the actual setpoint that is being used for control during
heating mode. If a 0 is displayed, then space sensor control is not
being used and the unit is being controlled by a thermostat.
Currently Occupied (OCC)
Displays the current state of assumed space occupancy based on
unit configuration and inputs.

Timed Override in Effect (T.OVR)

Displays if the state of occupancy is currently occupied due to an
override.
Linkage Active (LINK)
Displays if a linkage communication "Linkage" is established
between the unit and a linkage source.
Demand Limit in Effect (D.LMT)
Displays if a demand limit has been placed on the unit's capacity.
Compressor OAT Lockout (C.LOC)
Displays if operation of one or more compressors is prevented due
to outdoor temperature limit lockout.
Heat OAT Lockout (H.LOC)
Displays if heating operation is prevented due to outdoor
temperature limit lockout.
Econo Cool OAT Lockout (E.LOC)
Displays if economizer operation for cooling is prevented due to
outdoor temperature limit lockout.

General Operation

48/50PG and 48/50PM
dehumidification, heating, and ventilation operation. Each unit
will operate under one of two basic types of control: thermostat or
space temperature sensor. There are many inputs, configurations,
safety factors, and conditions that ultimately control the unit. Refer
to the specific operation sections for detail on a specific unit
operation.
units can provide cooling,
When thermostat control is enabled (Configuration→UNIT
→U.CTL = 1), the unit will operate based on discrete input
commands (G, Y1, Y2, W1, and W2) and there is a one minute
time delay between modes and when re−entering a mode. The G
command calls for ventilation, the Y1 and Y2 commands call for
cooling, and the W1 and W2 commands call for heating.
Thermostat Control Type (Configuration→UNIT→T.CTL) affects
how cooling operates based on Y1 and Y2 commands and if
cooling/heating stage time guards are applied.
When space temperature sensor control is enabled (Configuration
→UNIT→U.CTL = 2), the unit will try to maintain the Space
Temperature (Temperatures→AIR.T→SPT) between the effective
cool and heat setpoints (Run Status→MODE→EFF.C and
EFF.H). However, to minimize unnecessary cool to heat and heat
to cool changes, there is a 10 minute delay after the last stage turns
off before the control will switch modes and a 1 minute delay when
re−entering the last mode. Linkage operation overrides the mode
changeover delay to 15 seconds. The cooling and heating Mode
Select Timeguard (Operating Modes→COOL→MS.TG and
Operating Modes→HEAT→MS.TG) show the remaining time
before allowing the respective mode to be entered.

Temperature Setpoint Determination

Setpoints are used to control the unit while under space
temperature sensor control. The Cool Setpoint in Effect (EFF.C)
and the Heat Setpoint in Effect (EFF.H) are the points in which the
unit is controlling to at a specific time. These points are read only
points and change according to occupancy, the offset slider status,
and network writes (Linkage or LON).
If the building is in occupied mode, the Occupied Cool Setpoint
(Setpoints→OCSP) and the Occupied Heat Setpoint (Setpoints
→OHSP) are active. When the building is in unoccupied mode,
the Unoccupied Cool Setpoint (Setpoints→UCSP) and the
Unoccupied Heat Setpoint (Setpoints→UHSP) are active. The
heating and cooling set points are also separated by a Heat−Cool
Set Point Gap (Setpoints→GAP) that is user configurable from 2
to 10 degrees F. This parameter will not allow the setpoints to be
set too close together, it will change the last setpoint adjusted if it is
set within the GAP.
When the space sensor has a setpoint slider adjustment, the cool
and heat setpoints (occupied) can be offset by sliding the bar from
one side to the other. The SPT Offset Range (+/−) (Setpoints
→STO.R) sets the total positive or negative degrees that can be
added to the setpoints. With the slider in the middle, no offset is
applied. Moving the slider to the "COOL" side will subtract from
each setpoint, and sliding it to the "WARM" side will add to the
setpoints. The slider offset being applied at any given time is
displayed as Space Temperature Offset (Temperatures→AIR.T
→SPTO).
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