Minimum And Maximum Potentiometers Adjustments; Zone Sensor Wiring - Trane VariTrane Installation/ Owner Programming

Figure 4 – Typical Analog Electronic
Control Wiring Diagram
Avoid Wiring Errors!
It is important to connect power and zone sensor control voltage wiring to the proper
terminals since improper connection will cause failure of the circuit board. To help
prevent errors, the 24 VAC power to circuit board zone sensor connections
are labeled.
Minimum and Maximum
Potentiometers Adjustments
The minimum and maximum flow (or
position) setpoints may require field
setting to obtain desired cfm settings.
Refer to the calibration section of this
manual for proper adjustment
procedures.
On single-duct boxes where transform-
ers are optional, the transformer must
be NEC Class 2, energy-limiting, 24 VAC.
Refer to electrical data for proper sizing.
Hazardous Voltage!
Disconnect all electric power, including
remote disconnects before servicing.
Follow proper lockout/tagout proce-
dures to ensure the power cannot be
inadvertently energized. Failure to
disconnect power before servicing could
result in death or serious injury. Prior to
replacing the zone sensor, follow
warning instructions above.
8
Analog
Controls

Zone Sensor Wiring

Each unit must be controlled by a wall-
or unit-mounted zone sensor which is
designed specifically for use with a
solid-state circuit board that is provided
by the factory.
Two types of zone sensors are available
with analog electronic controls. One has
the thumbwheel visible, while the other
is hidden by the cover.
NOTE: Analog electronic zone sensors
are not interchangeable with DDC
zone sensors.
The three wires required for the wall
zone sensor to the terminal block are to
be furnished and completed by
the installer.
If local codes require enclosed
conductors, the zone sensor wires
should be installed in conduit. Do not
route zone sensor wires in conduit with
24-volt or any high-powered conducting
wires. This will cause electrical noise
and result in erratic operation of
the controls.
Circuit Board Damage!
Before handling the circuit board,
discharge any static electricity you may
have accumulated by touching the unit
casing. Static charges produce voltages
high enough to damage the electronic
components.
Location and Installation
A zone sensor in each control zone
should be located in the most critical
area of the zone. Sensors should not be
installed in direct sunlight or in the
area's supply air stream. Subdivision of
the zone may be necessary for ad-
equate control and comfort.
Avoid installing zone sensors in areas
subject to the following:
— Drafts or "dead spots" behind doors
or corners.
— Hot or cold air ducts.
— Radiant heat from the sun or
appliances.
— Concealed pipes or chimneys.
— Unheated or uncooled surfaces behind
the sensor such as outside walls.
— Air flows from adjacent zones or
other units.
VAV-SVX03A-EN