Technical data

Standard Features—1.5- to 3-Ton Systems
3
2.5 System Controls
System controls include a microprocessor control board mounted in the evaporator/chilled water unit
and a wall-mounted interface with a two-line, 16-character liquid crystal display. An eight-key, mem-
brane keypad for setpoint/program control, unit On/Off, fan speed and alarm silence is below the LCD
screen. It provides temperature setpoint and sensitivity adjustment, humidity setpoint and sensitiv-
ity adjustment, digital display of temperature, humidity, setpoints, sensitivities, fan speed and alarm
conditions.
The wall-box is field-wired to the microprocessor control using standard four-conductor thermostat
wire (field-supplied). The temperature and humidity sensors are in the wall box, which can be
installed up to 300 feet (91.4m) from the evaporator unit. The unit-mounted control board also
includes common alarm terminals and shutdown terminals. The unit automatically restarts after a
power outage.
Figure 1 Wall-box
2.5.1 Other Standard Control Features
• Adjustable auto restart • Calibrate sensors
• 5 day/2 day setback • Predictive humidity control
• Password protection • Common alarm output
• Alarm enable/disable • Remote shutdown terminals
• Self-diagnostics