Communications

Electrical Data

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.

The microprocessor shall be compatible with all Liebert remote monitoring and control devices.

2.1.5Advanced Microprocessor Control with Graphics (Optional)

The optional Advanced control processor shall be microprocessor based with a front monitor dot matrix display panel and control keys for user inputs. The controls shall be menu driven with on- screen prompts for easy user operation. The system shall allow user review and programming of tem- perature and humidity setpoints, alarm parameters, and setup selections including choice of control type. A password shall be required to make system changes. For all user selections, the range of acceptable input (temperature, humidity, or time delay) shall be displayed on the monitor screen. The system shall provide monitoring of room conditions, operational status in % of each function, compo- nent run times, date and time, and four analog inputs from sensors provided by others.

Control

The control system shall allow programming of the following room conditions:

•Temperature Setpoint 65 to 85°F (18-29°C)

•Temperature Sensitivity +1 to +9.9°F (0.6 to 5.6°C) in 0.1° increments

•Humidity Setpoint 20 to 80% RH

•Humidity Sensitivity +1 to +30% RH

All setpoints shall be adjustable from the individual unit front monitor panel.

Temperature and Humidity Sensors shall be capable of being calibrated using the front monitor panel controls to coordinate with other temperature and humidity sensors in the room.

Predictive Humidity Control

The microprocessor shall calculate the moisture content in the room and prevent unnecessary humid- ification and dehumidification cycles by responding to changes in dew point temperature.

Compressor Short-Cycle Control

The control system shall include a program to prevent 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 microprocessor shall sequence operational load activation to minimize inrush current. Systems allowing multiple loads to start simultaneously are unaccept- able.

Chilled Water/Hot Water/Econ-O-Coil Flush Cycles

Chilled water, hot water, and Econ-O-Cool coils shall be automatically flushed to prevent the buildup of contaminants. Systems without 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 240 x 120 dot matrix display panel with adjustable backlighting. This display (along with five front mounted control keys) shall be the only operator interface required to obtain all available system information such as room conditions, operational sta- tus, graphical data, alarms, control and alarm setpoints, 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.