Carrier WeatherExpert 48N2 Controls, Start-Up, Operation, Service, And Troubleshooting page 40

HVAC Mode — DISABLED (1)
The unit is shut down due to a command software disable
through the scrolling marquee, a CCN emergency stop com-
mand, a service test end, or a
control-type change delay.
HVAC Mode — SHUTTING DOWN (2)
The unit is transitioning from a mode to the OFF mode.
HVAC Mode — SOFTSTOP REQUEST (3)
The unit is off due to a soft stop request from the control.
HVAC Mode — REM SW.DISABLE (4)
The unit is off due to the remote switch.
HVAC Mode — FAN STATUS FAIL (5)
The unit is off due to a supply fan status failure.
HVAC Mode — STATIC PRESSURE FAIL (6)
The unit is off due to failure of the static pressure sensor.
HVAC Mode — COMP.STUCK ON (7)
The unit is shut down because there is an indication that a com-
pressor is running even though it has been commanded off.
HVAC Mode — OFF (8)
The unit is off and no operating modes are active.
HVAC Mode — TEST (9)
The unit is in the self-test mode, which is entered through the
Service Test menu.
HVAC Mode — TEMPERING VENT (10)
The economizer is at minimum vent position, but the supply-
air temperature has dropped below the tempering vent set
point. Staged gas heat, modulating gas heat, SCR electric heat,
or hydronic heat is used to temper the ventilation air.
HVAC Mode — TEMPERING LOCOOL (11)
The economizer is at minimum vent position, but the combina-
tion of the outside-air temperature and the economizer position
has dropped the supply-air temperature below the tempering
cool set point. Staged gas heat, modulating gas heat, SCR elec-
tric heat, or hydronic heat is used to temper the ventilation air.
HVAC Mode — TEMPERING HICOOL (12)
The economizer is at minimum vent position, but the combina-
tion of the outside-air temperature and the economizer position
has dropped the supply-air temperature below the tempering
cool set point. Staged gas heat, modulating gas heat, SCR elec-
tric heat, or hydronic heat is used to temper the ventilation air.
HVAC Mode — VENT (13)
This is a normal operation mode where no heating or cooling is
required and outside air is being delivered to the space to con-
trol IAQ levels.
HVAC Mode — LOW COOL (14)
A normal cooling mode where a low cooling demand is present.
HVAC Mode — HIGH COOL (15)
A normal cooling mode where a high cooling demand is present.
HVAC Mode — LOW HEAT (16)
The unit will be in low heating demand mode using either gas,
electric, or hydronic heat.
HVAC Mode — HIGH HEAT (17)
The unit will be in high heating demand mode using gas, elec-
tric, or hydronic heat.
HVAC Mode — UNOCC. FREE COOL (18)
In this mode the unit will operate in cooling but will be using the
economizer for free cooling. Entering this mode will depend on
the status of the outside air. The unit can be configured for out-
side air dry bulb changeover, differential dry bulb changeover,
outside air enthalpy changeover, differential enthalpy change-
over, or a custom arrangement of enthalpy/dew point and dry
bulb. See the Economizer section for further details.
HVAC Mode — FIRE SHUT DOWN (19)
The unit has been stopped due to a fire shutdown input (FSD)
from 2 or more of the fire control modes: purge, evacuation, or
pressurization.
HVAC Mode — PRESSURIZATION (20)
The unit is in the special fire pressurization mode where the
supply fan is on, the economizer damper is open, and the pow-
er exhaust fans are off. This mode is invoked by the Fire Pres-
surization (PRES) input, which can be found in the INPUT-
FIRE submenu.
HVAC Mode — EVACUATION (21)
The unit is in the special Fire Evacuation mode where the sup-
ply fan is off, the economizer damper is closed, and the power
exhaust fans are on. This mode is invoked by the Fire Evacua-
tion (EVAC) input, which can be found in the INPUTFIRE
submenu.
HVAC Mode — SMOKE PURGE (22)
The unit is in the special Fire Purge mode where the supply fan
is on, the economizer damper is open, and the power exhaust
fans are on. This mode is invoked by the Fire Evacuation
(PURG) input, which can be found in the INPUTFIRE submenu.
HVAC Mode — COOLING DEHUM (23)
The unit is operating in Cool mode and dehumidification is in
effect.
HVAC Mode — VENTING DEHUM (24)
The unit is operating in Vent mode and dehumidification is in
effect.
HVAC Mode — FREEZESTAT TRIP (25)
If the freezestat trips, the unit enters the Freezestat Trip HVAC
mode. The supply fan will run, the hydronic heat valve will be
wide open, and the economizer damper will be closed.
HVAC Mode — PLEN.PRESS.FAIL (26)
The unit is off due to a failure of the plenum pressure switch.
HVAC Mode — RCB COMM FAILURE (27)
The unit is off due to a Rooftop Control Board (RCB) commu-
nication failure.
HVAC Mode — SUPPLY VFD FAULT (28)
The unit is off due to a supply fan VFD fault or supply fan
VFD communications loss.
HVAC Mode — AIR PRESSURE SWITCH FAIL (29)
If there is an air pressure safety switch error, the unit enters Air
pressure switch failure mode.
HVAC Mode — THREE PHASE POWER FAIL (30)
If the unit is configured for power monitoring and there is a
power error, the unit enters Power failure mode.
HVAC Mode — HEATING DEHUM (31)
Unit is operating in Heat mode and dehumidification is in effect.
HVAC Mode — DUCT STATIC PRESSURE FAIL (32)
If the unit is a VAV unit with a supply duct pressure sensor and
measured supply duct static pressure is above the configurable
SP Low Alert Limit, the unit enters this mode.
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