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Wiring inputs and outputs

TruVu™ VVTZC

-E2

Installation and Start-up Guide

Zone airflow control

The TV-VVTZC-E2 provides pressure-dependent zone temperature control by modulating its built-in damper
actuator to control the flow of primary air into the zone. The controller uses PID control to calculate the damper
position based on the difference between the

zone’s temperature and setpoints.

The air source mode determines if the primary air can meet the zone’s need. If the zon

e controller is in a linked

system, the air source mode is determined by the air source. If the zone controller is stand-alone or if linkage
communication fails, the mode is determined by the controller's SAT. See

Air source mode determination

(page

65)

. If the air source mode is the same as the zone’s local mode, the damper is positioned between the mode’s

configurable minimum and maximum damper position. If not, the damper is positioned at the mode's minimum
damper position to insure sufficient minimum airflow at the air source.

When the air source mode is Vent and the zone’s temperature demand is satisfied, the damper moves to its

Vent

Position

to increase airflow and ventilation to the space.

Single duct with reheat

–

The

Reheat Min Damper Position

allows an increase of primary airflow across the

terminal’s ducted heating coil when the terminal is operating its local heat while the air source mode is Cool. This

provides the ability to lower the cooling minimum airflow limits while providing the necessary airflow when the
terminal is heating to ensure design load conditions and electric heater minimum airflow.

Parallel fan terminals

–

The controller's

Parallel Fan On Value

determines when the fan turns on to increase

airflow a

t the zone’s diffus

ers and prevent cold air from dumping into the zone when the system mode is Cool.

This is achieved by increasing the volume and temperature of the air exiting the diffusers. Should the zone’s

damper close below the

Parallel Fan On Value

, the parallel fan is energized to mix ceiling plenum air with the

primary air to increase total airflow and ventilation to the zone. The fan turns off when the damper position opens
to 1% above the setpoint.

The fan also starts in Heat mode if the zone is configured for ducted heat as described in Zone reheat control.

Series fan terminals

–

The fan energizes when the air source fan is on if the zone controller is part of a linked

system or in the unoccupied heat mode and the equipment fan is off. If the zone controller is stand-alone, the fan
runs continuously. There is a fan start delay on transition to occupied, based on the

Power Fail Start Delay

. Before

the fan starts, the damper closes. The damper position must be less than 5% for 10 seconds before the fan starts
to prevent the fan from starting backwards.

See

Appendix B: VVT terminal modes

(page 130).

Damper Actuator(s)

–

The TV-VVTZC-E2's built-in 45 in/lb (5 Nm) actuator has a 154 second full travel time for

90° operation. For field retrofit applications, the actuator can be adjusted for a damper stroke between 30° and
90°, and it can be configured to move clockwise (default) or counterclockwise.

If the built-in actuator's torque is insufficient for large damper applications, the TV-VVTZC-E2's analog output can
drive an external, 0-10 volt, high-torque actuator. Or, the controller can drive one or more additional slave
actuators. A slave actuator must be mounted and configured to fully close the damper when the output signal is 0
volts. See

Wiring field-supplied actuators to the analog output.

(page 50)

Zone reheat control

The TV-VVTZC-E2 can be configured for one of the following

Heat Types

to meet the zone's heating requirements:

•

Modulating Hot Water/Steam

•

Modulating SCR Electric

•

Two Position Hot Water/Steam