Dehumidification; Space Temperature Alarms; Condenser Water Temperature Monitoring/Control/Alarm; High Condensate / Overflow Alarm - Carrier Aquazone 50HQP Series Installation, Start-Up And Service Instructions Manual

DEHUMIDIFICATION

The control can monitor the space relative humidity and if the unit
is equipped with the factory installed hot gas reheat, whenever the
humidity exceeds the appropriate (occupied or unoccupied) hu-
midity setpoint and if the unit is not heating or cooling, the control
will activate cooling (compressor and reversing valve) and the hot
gas reheat outputs to start dehumidification. The fan will operate
at medium speed if equipped with a 3-speed fan.

SPACE TEMPERATURE ALARMS

The control provides the ability to generate an alarm whenever the
space temperature exceeds the alarm setpoint. A separate occupied
hysteresis and unoccupied high and low alarm setpoints are pro-
vided. The control provides a 5 minute alarm delay during unoc-
cupied periods. During occupied periods, the control uses the oc-
cupied temperature setpoint and applies the hysteresis value to de-
termine the alarm setpoints. Whenever an occupancy transition
from unoccupied to occupied occurs or the occupied temperature
setpoints are changed causing an alarm condition to occur, the
control will automatically calculate an alarm delay (equivalent to
the configured delay time in minutes / degrees F times the tem-
perature error that occurred). This will prevent nuisance alarms
whenever an occupancy change occurs and allows time for the
unit to correct an alarming temperature condition.
CONDENSER WATER TEMPERATURE MONITORING/
CONTROL/ALARM
The control has 4 configurable alarm limits for condenser water
temperature. The control will verify that the water temperature is
within operating range (between high and low limits) for the spe-
cific operating mode (heating or cooling) before energizing the
compressor. Once the compressor is started, the condenser water
temperature is further monitored to verify that it is within limits to
insure sufficient water is flowing through the coil. Should the
leaving water temperature rise above or fall below the appropriate
limits, and alarm is generated and the compressors will be shut
down if the condition occurs for more than 15 seconds.

HIGH CONDENSATE / OVERFLOW ALARM

The control will monitor a discrete input to determine the state of a
condensate level switch. The input can be configured to alarm on
either an open or closed switch condition. Should this input be in
an alarm state, the control will start a timer and after the timer ex-
ceeds a configurable 'Condensate Overflow Alarm Delay' limit
(10 seconds default), the control will generate an alarm and the
unit will disable the compressor, dehumidification and fan outputs.

FILTER STATUS ALARM

The control provides the ability to generate a dirty filter alarm af-
ter the number of fan run hours exceeds a configurable filter alarm
timer limit. The control monitors the fan output and if the fan is
operating at any speed, it accumulates run time. Should the fan run
time hours exceed the configurable limit, an alarm is generated. To
reset the alarm timer after the alarm has been generated, a 'Reset
Filter Alarm' input is provided. The filter alarm can be disabled by
setting the 'Filter Alarm Timer Delay' to zero (factory default).

COMPRESSOR FAULT/LOCKOUT ALARM

The control will monitor a discrete input to determine the com-
pressor state. Should the input state not match the desired com-
pressor operating state for greater than 6 minutes, the control as-
sumes the compressor has been locked-out and will generate an
alarm. Also, when this fault occurs and if the unit is equipped with
an auxiliary heating coil or a water economizer and the water tem-
perature is suitable for heating, should heating be required, the
control will utilize the auxiliary heating source as the primary
heating source until the fault condition is corrected.
INSUFFICIENT VENTILATION ALARM
The control provides the ability to generate a high CO
during occupied periods whenever the CO
the user adjustable limit. Whenever an occupancy transition from
unoccupied to occupied occurs, or the occupied alarm limit
is changed to a value that causes an alarm condition to occur, the
control will automatically calculate an alarm delay based on the
error from setpoint (15 minutes minimum). This prevents nuisance
alarms from occurring when occupancy changes. The IAQ alarm
can be disabled by setting 'Occupied High IAQ Alarm Limit' to
zero.
RELATIVE HUMIDITY ALARM
The control provides the ability to generate an alarm whenever the
space relative humidity exceeds the alarm setpoint. A separate oc-
cupied and unoccupied alarm setpoint is provided. The control
provides a 5 minute alarm delay during unoccupied periods.
During occupied periods, the controller uses the occupied high RH
alarm limit. Whenever an occupancy transition from unoccupied
to occupied occurs or the occupied high alarm limit is lowered
causing an alarm condition to occur, the control will automatically
calculate an alarm delay (equivalent to the configured delay time
in minutes / % RH times the humidity error condition that oc-
curred). This will prevent nuisance alarms whenever an occupan-
cy change occurs and allows time for the unit to correct an alarm-
ing humidity condition.
TIME SCHEDULES
The control has an onboard time clock and configurable time
schedules to provide occupancy scheduling.
HOLIDAY SCHEDULES
The control has holiday schedules that can be programmed to
override the normal occupancy operation and cause the unit to go
unoccupied for the duration of the schedule. Each schedule con-
sists of a start date and time and an end date and time so each
schedule can span more than a single day duration.
OVERRIDE SCHEDULES
The control has override schedules that can be programmed to
override the normal occupancy and holiday operation and cause
the unit to go occupied for the duration of the schedule. Each
schedule consist of a start date and time and an end date and time
so each schedule can span more than a single day duration.
41
level alarm
2
sensor value exceeds
2