Trane UniTrane Fan Coil Скачать руководство пользователя страница 105

Страница: 105 / 160

Startup

UNT-SVX07E-EN

105

Supply Fan Operation

Refer to

Table 47

for fan mode operation. The controller

will operate in either continuous fan or fan cycling mode.
The fan cycles when the fan mode switch is placed in auto.
The fan runs continuous when placed in the high, medium,
or low position. Use Rover, Trane’s installation and service
tool, to change auto defaults.

During the transition from off to any fan speed but high,
the controller automatically starts the fan on high speed
and runs for three seconds before transitioning to the
selected speed (if it is other than high). This provides
enough torque to start all fan motors from the off position.
When the heating output is controlled off, the controller
automatically controls the fan on for an additional 30
seconds. This delay allows the fan to dissipate any residual
heat from the heating source, such as electric heat.

Tracer ZN520 Controllers

Tracer ZN520 controller is a discrete speed controller that
can be used in a stand-alone application or can
communicate with a building automation system using
LonTalk Communication.

ZN520 Stand-Alone Operation

The factory pre-programs the Tracer ZN520 with default
values to control the temperature and unit airflow. Use
Tracer Summit building automation system or Rover™
software to change the default values. For more
information, refer to:

•

CNT-SVX04A-EN Installation, Operation, and
Maintenance manual for Tracer ZN520

Follow the procedure below to operate the Tracer ZN520 in
a stand-alone operation:

Turn power on at the disconnect switch option.

2. Position the fan mode switch to either high, medium,

low, or the auto position.

3. Rotate the setpoint dial on the zone sensor module to

55°F for cooling or 85°F for heating.

The appropriate control valve will actuate assuming the
following conditions:

•

Room temperature should be greater than 55°F and
less than 85°F.

•

For a 2-pipe fan-coil unit with an automatic changeover
sensor, the water temperature input is appropriate for
the demand placed on the unit. For example, cooling
operation is requested and cold water (5° lower than
room temperature) flows into the unit.

•

Select the correct temperature setpoint.

Note:

Select and enable zone sensor temperature
settings to prevent freeze damage to unit.

ZN520 Operation

Fan Mode Switch

Off

- Fan is turned off, two-position damper option spring-

returns closed.

Hi, Med, Lo

- Fan runs continuously at the selected speed.

The two-position damper option opens to an adjustable
mechanical stop position.

Controller

Off

- Fan is off; control valves and fresh air damper option

close. Low air temperature detection option is still active.

Auto

- Fan speed control in the auto setting allows the

modulating (3-wire floating point) or 2–position control
valve option and three-speed fan to work cooperatively to
meet precise capacity requirement, while minimizing fan
speed (motor/energy/acoustics) and valve position (pump
energy, chilled water reset). As the capacity requirement
increases at low fan speed, the water valve opens. When
the low fan speed capacity switch point is reached, the fan

Table 47.

Fan mode operation

Heating Mode

Cooling Mode

Fan mode

Occupied

Unoccupied

Occupied

Off

Low

Off/high

(a)