Trane VUV Installation, Operation And Maintenance Manual page 86

Start-Up
AUTO Fan Operation; ECM Energy Efficient
Mode
When the controller is configured for Energy Efficient Mode, by
means of the Fan Operating Mode Request MV point, the
controller and daughter board will minimize energy use by
running the fan at the lowest possible speed while maintaining
space temperature. The controller will fully utilize valves,
economizer, or electric heat which increases fan speed to meet
space temperature (unless the fan has been manually
controlled. Refer to the preceding section.
AUTO Fan Operation; ECM Acoustical Mode
When the controller is configured for Acoustical Mode, by
means of the Fan Operating Mode Request MV point, the
controller and daughter board will minimize acoustical
nuisance by balancing changes in fan speed and total fan
noise. The controller will fully OPEN cooling and heating
valves before increasing fan speed to meet space temperature
(unless the fan has been manually controlled. Refer to
Fan Speed Control," p. 85 in the preceding section. If multiple
stages of electric heat exist the controller will use a single
minimum air flow for each stage.
Exhaust Control
Exhaust control is achieved by a single-speed exhaust fan and
controlled by binary output 2 (BO2). Exhaust control, if not
present, can be enabled by selecting Yes under the Exhaust
Fan Selection on the Tracer® TU Configuration page under the
Equipment Options group.
Note: Exhaust fan configuration cannot be selected with 3-
speed fan operation.
Important: If exhaust control is added to an existing
configuration, all other configuration options
should be verified to match the correct
equipment options.Temperature and flow
setpoints will revert to default values.
The exhaust function is coordinated with the supply fan and
outdoor/return air dampers as follows:
• The exhaust fan energizes when the fan is running and
when the outdoor air damper position is greater than or
equal to the exhaust fan enable position (or the outside air
damper position at which the exhaust fan turns ON).
• The exhaust fan turns OFF when the fan either turns OFF
or the outdoor air damper closes to 10 percent below the
exhaust fan enable position.
• If the exhaust fan/damper enable setpoint is less than
10 percent, the exhaust output is energized if the outdoor
air damper position is at the setpoint and de-energized at 0.
Valve Operation
The controller supports one or two modulating or two-position
valves, depending on the application (refer
The controller opens and closes the appropriate valve(s) to
maintain the active zone temperature setpoint at the heating
setpoint in heating mode or the cooling setpoint in cooling
mode (refer to "Cascade Zone Control,"
86
Three-Wire Modulating Valve Operation
The controller supports tri-state 3-wire modulating valve
control. Two binary outputs control each valve: one to drive the
valve open and one to drive the valve closed. The stroke time
for each valve is configurable using the Tracer® TU service
tool. The controller supports the following:
•
•
•
•
•
The controller moves the modulating valve to the desired
positions based on heating or cooling requirements.
"Manual
Three-Wire Modulating Valve Calibration
Modulating valve calibration is automatic. During normal
controller operation, the controller overdrives the actuator
(135 percent of the stroke time) whenever there is a request for
a position of 0 percent or 100 percent. At either power-up, after
a power outage, or when the occupancy status changes to
unoccupied, the controller first drives all modulating valves
(and dampers) to the closed position. The controller calibrates
to the fully CLOSED position by over driving the actuator
(135 percent of the stroke time). Thereafter, the controller
resumes normal operation.
Two-position Valve Operation
The controller supports two-position valves with a single binary
output for each valve. Controllers used for 2-pipe applications
support heating, cooling, or heat/cool changeover with a single
valve/coil. A controller used for 4-pipe applications supports
cooling or heat/cool changeover with a main valve/coil and
heating only with an auxiliary valve/coil.
Modulating Outdoor/Return Air Damper
The controller operates the modulating outdoor/return air
dampers based on the following:
•
•
•
•
•
•
The minimum position for an outdoor air damper is
configurable using the Tracer® TU service tool for both
Table 33, p. 87).
occupied mode and occupied standby mode and for low-speed
fan operation. A controller can receive a BAS-communicated
outdoor air damper minimum position.
p. 84).
Heating
Cooling
Heat/cool changeover with a single valve and coil for 2-
pipe applications
Cooling or heat, cool changeover with the main valve, and
coil
Only heating with the auxiliary valve and coil for 4-pipe
applications
Occupancy mode
Outdoor air temperature (communicated or hard wired
sensor)
Zone temperature
Setpoint
Discharge air temperature
Discharge air temperature setpoint
UV-SVX005G-EN