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occupied hysteresis and unoccupied high and low alarm set
points are provided. The control provides a 5 minute alarm delay
during unoccupied periods. During occupied periods, the control
uses the occupied temperature set point and applies the
hysteresis value to determine the alarm set points. Whenever an
occupancy transition from unoccupied to occupied occurs or the
occupied temperature set points are changed causing an alarm
condition to occur, the control will automatically calculate an
alarm delay (equivalent to the configured delay time in minutes /
deg F times the temperature 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
specific 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
exceeds 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
after 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
compressor state. Should the input state not match the desired
compressor operating state for greater than 6 minutes, the control
assumes 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
temperature 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 set point (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.
level alarm
2
sensor value exceeds
2
55
RELATIVE HUMIDITY ALARM
The control provides the ability to generate an alarm whenever the
space relative humidity exceeds the alarm set point. A separate
occupied and unoccupied alarm set point 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
occurred). This will prevent nuisance alarms whenever an
occupancy change occurs and allows time for the unit to correct an
alarming 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
consists 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 consists of a start date and time and an end date and time
so each schedule can span more than a single day duration.
SERVICE
Perform the procedures outlined below periodically, as indicated.
An annual "checkup" is recommended by a licensed refrigeration
mechanic. Recording the performance measurements of volts,
amps, and water temperature differences (both heating and
cooling) is recommended. This data should be compared to the
information on the unit's data plate and the data taken at the
original start-up of the equipment.
Periodic lockouts almost always are caused by air or water flow
problems. The lockout (shutdown) of the unit is a normal
protective measure in the design of the equipment. If continual
lockouts occur call a mechanic immediately and have them check
for: water flow problems, water temperature problems, airflow
problems or air temperature problems. Use of the pressure and
temperature charts for the unit may be required to properly
determine the cause.
IMPORTANT: When a compressor is removed from this unit,
system refrigerant circuit oil will remain in the compressor. To
avoid leakage of compressor oil, the refrigerant lines of the
compressor must be sealed after it is removed.
WARNING
To avoid injury and the discharge of refrigerant into the
environment, all refrigerant discharged from this unit must be
recovered without exception. Technicians must follow
industry accepted guidelines and all local, state and federal
statutes for the recovery and disposal of refrigerants.
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