user manual

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Temperature and Humidity Sensors shall be capable
of being calibrated using the front monitor panel con-
trols to coordinate with other temperature and
humidity sensors in the room.
Predictive Humidity Control
The microprocessor shall calculate the moisture con-
tent in the room and prevent unnecessary humidifi-
cation and dehumidification cycles by responding to
changes in dew point temperature.
Compressor Short-Cycle Control
The control system shall include a program to pre-
vent compressor short-cycling.
System Auto-Restart
For start-up after power failure, the system shall
provide automatic restart with a programmable (up
to 9.9 minutes in 6-second increments) time delay.
Programming can be performed either at the unit or
from the central site monitoring system.
Sequential Load Activation
During start-up, or after power failure, the micropro-
cessor shall sequence operational load activation to
minimize inrush current. Systems allowing multiple
loads to start simultaneously are unacceptable.
Chilled Water/Hot Water/Econ-O-Coil Flush
Cycles
Chilled water, hot water, and Econ-O-Cool coils (if
unit is so equipped) shall be automatically flushed to
prevent the buildup of contaminants. Systems with-
out this feature shall include the necessary devices to
bypass fluid into the coil on a programmed basis.
Front Monitor Display Panel
The microprocessor shall provide a front monitor
LCD backlit display panel with 4 rows of 20 charac-
ters with adjustable contrast. This display (along
with five front mounted control keys) shall be the
only operator interface required to obtain all avail-
able system information such as room conditions,
operational status, alarms, control and alarm set-
points, and all user selections including alarm
delays, sensor calibration, DIP switch selections, and
diagnostics. All indicators shall be in language form.
No symbols or codes shall be acceptable.
Alarms
The microprocessor shall activate an audible and
visual alarm in event of any of the following conditions:
High Temperature
Low Temperature
High Humidity
Low Humidity
Short Cycle
Compressor Overload (Optional)
Main Fan Overload (Optional)
Humidifier Problem
High Head Pressure
Change Filter
Loss of Air Flow
Low Suction Pressure
Loss of Power
Custom Alarm (#1 to #4)
Custom alarms are four customer accessible alarm
inputs to be indicated on the front panel. Custom
alarms can be identified with prepared (pro-
grammed) alarm labels for the following frequently
used inputs:
Water Under Floor
Smoke Detected
Standby GC Pump On
Loss of Water Flow
Standby Unit On
User customized text can be entered for two of the
four custom alarms. Each alarm (unit and custom)
can be separately enabled or disabled, selected to
activate the common alarm, and programmed for a
time delay of 0 to 255 seconds.
Audible Alarm
The audible alarm shall annunciate any alarm that
is enabled by the operator.
Common Alarm
A programmable common alarm shall be provided to
interface user selected alarms with a remote alarm
device.
Remote Monitoring
All alarms shall be communicated to the Liebert
monitoring system with the following information:
date and time of occurrence, unit number, and
present temperature and humidity.
Analog Inputs
The system shall include four customer accessible
analog inputs for sensors provided by others. The
analog inputs shall accept a 4 to 20 mA signal. The
user shall be able to change the input to 0 to 5 VDC
or 0 to 10 VDC if desired. The gains for each analog
input shall be programmable from the front panel.
The analog inputs shall be able to be monitored from
the front panel.
Diagnostics
The control system and electronic circuitry shall be
provided with self-diagnostics to aid in troubleshoot-
ing. The microcontroller board shall be diagnosed
and reported as pass/not pass. Control inputs shall
be indicated as on or off at the front monitor panel.
Control outputs shall be able to be turned on or off
from the front monitor panel without using jumpers
or a service terminal. Each control output shall be
indicated by an LED on a circuit board.
Data Collection
The control system shall maintain accumulative
operating hours of compressor, reheat, humidifier,
fan motor, and Econ-O-Coil. The ten most recent
alarms shall also be retained.
Communications
The microprocessor shall be compatible with all Lie-
bert remote monitoring and control devices.
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