LX Series Unit Ventilator Controller User's Guide
23
Fan State Input
The fan state input detects whether one of the three fan speeds is ON or OFF. If the
fan state input does not correspond with one of the fan outputs for a time period
known as the alarm delay, then an alarm becomes active. If the fan state input is
OFF, while one of the fan outputs is ON, then equipment requiring air circulation
remains OFF or does not modulate.
Note:
All outputs except for the fan are disabled when the fan state is OFF.
Mixed Air Temperature Input
The mixed air temperature can be monitored by an alarm, thereby provide early
warning of any malfunction.
Without mixed air and discharge air temperatures, the outside air damper cannot
exceed the minimum position as determined by the Fresh Air Minimum Input
Damper Position on the General Settings screen of the LX-UVL configuration
wizard.
See the
Mode Selector
Mode Selector enables selection of different modes of operation by means of an
analog signal, such as resistance, voltage, or current input.
The modes of operation available for selection from this input are auto, heat, cool,
fan only, and OFF. Table 2 describes the modes of operation.
Table 2: Modes of Operation
Mode of
Operation
Description
Auto
Operates according to its setpoints and scheduled occupancy states; this means
that the Unit Ventilator Controller controls heating, cooling, duct pressure, and the
fresh air damper, according to the setpoints and the configuration properties you
enter. The Unit Ventilator Controller switches between unoccupied, occupied,
standby, and bypass modes according to its schedule, and between the occupancy
and bypass contacts if these contacts are present.
Heat
Operates according to the heating setpoints in heating mode only. The heating
setpoint may change as the controller switches scheduled states. Cooling mode is
unavailable. The fan is ON when heating is ON; the fan is OFF at other times
unless configured as ON during occupied periods.
Cool
Operates according to the cooling setpoints in cooling mode only. The cooling
setpoints may change as the controller switches scheduled states. Heating mode
is unavailable. The fan is ON when cooling is ON; the fan is OFF at other times
unless configured as ON during occupied periods.
Fan Only
Configures the fan ON during the scheduled occupied state. Heating and cooling is
not available. Fan configuration is found on the Fan-Valve screen of the Unit
Ventilator Controller configuration wizard.
OFF
Disables the control loop to OFF. All outputs are in the OFF state.