Installing the VVT Bypass II ......................................................................................................................................... 6
Sequence of operation .............................................................................................................................................. 26
To adjust the driver properties.................................................................................................................................. 29
What is a VVT Bypass II? ...................................................................................................................................... 1
Mounting the VVT Bypass II ................................................................................................................................. 7
To mount the controller and actuator .................................................................................................. 7
Wiring the VVT Bypass II for power ................................................................................................................. 12
To wire the controller for power .......................................................................................................... 13
Addressing the VVT Bypass II ........................................................................................................................... 14
Wiring for communications .............................................................................................................................. 14
Wiring specifications for BACnet MS/TP and ARC156 ...................................................................... 14
To wire the controller to the BACnet network .................................................................................... 15
Wiring inputs and outputs ................................................................................................................................ 16
Wiring a Duct Air Temperature sensor to an input ............................................................................ 16
Wiring field-supplied actuators to the analog output ........................................................................ 17
Wiring and mounting the Equipment Touch to the Rnet port ........................................................... 20
Wiring the TruVu™ ET Display to the Rnet port ................................................................................. 21
Configuring the VVT Bypass II's properties .................................................................................................... 22
Performing system checkout ........................................................................................................................... 23
Variable frequency drive (VFD) ........................................................................................................... 24
Duct static pressure control ............................................................................................................................. 26
LAT monitoring and limiting ............................................................................................................................. 26
Equipment fan off detection ............................................................................................................................ 27
Supply Air Temperature Alarm ........................................................................................................................ 27
Air source mode determination....................................................................................................................... 28
Common Alarms ................................................................................................................................................ 32
Specific Events ................................................................................................................................................... 33
To get the serial number .................................................................................................................................. 36
To restore factory defaults ............................................................................................................................... 36
To replace the battery ....................................................................................................................................... 37
To clean the airflow sensor orifice .................................................................................................................. 37
CE Compliance ................................................................................................................................................... 39
Appendix A: VVT Bypass II Points/Properties ......................................................................................................... 40
Appendix B: BACnet points list ................................................................................................................................ 45
Document revision history ........................................................................................................................................ 46
Unit Configuration .............................................................................................................................................. 40
The VVT Bypass II (#OPN-VVTBP-02), a component of the i-Vu® Control System, regulates the supply duct static
pressure by controlling one of the following:
•The system's bypass damper
The controller's damper actuator provides 45 in/lbs (5 Nm) of torque. If the actuator's torque is insufficient,
the VVT Bypass II can be used to drive an external high-torque actuator. Or, the controller can drive multiple
external damper actuators.
•The air source supply fan's variable frequency drive (VFD)
The VVT Bypass II controller is available in both English or Metric units. The metric version has (-M)
appended to the part number. Everything in this document applies to both versions.
The i-Vu Control System uses linkage to exchange data between the zone terminals and their air source to form a
coordinated HVAC system. The system's air source controller, zone controllers, and bypass controller are linked so
that their data exchange can be managed by one zone controller configured as the VVT Master.
You can disconnect the actuator from the controller and mount them separately, connecting them with just the
actuator cable or using an additional extension cable, up to a maximum distance of 300 feet.
The following illustration shows the VVT Bypass II in a typical i-Vu® Control System.
Act Net port To connect the actuator cable and the VVT Bypass II
BACnet port
Rnet port You can connect:
Local Access port For system start-up and troubleshooting
Input 1 input for connecting the Duct air temperature sensor (#33ZCSENDAT)
For communication with the controller network using BACnet ARC156 (156 kbps)
or BACnet MS/TP (9600 bps – 76.8 kbps)
One Equipment Touch, using an external 24 Vac power supply
or
One TruVu™ ET Display, using an external 24 Vdc power supply
Input resolution 10 bit A/D
Analog output 1 analog output, 0–10 Vdc (5 mA max).
The controlled device must have a minimum of 2000 Ohms resistance measured
from its input to ground and must share the same ground as the controller.
Output resolution 8 bit D/A
Integral airflow sensor Precision differential pressure sensor 0–2 in. H2O, sensitive down to ±0.001 in.
H2O. Barbed tapered airflow connections accept 3/16 in. (4.75 mm) I.D. tubing.
Allows for readings across the 0–2 in. H2O range, accurate to ±5% of full flow at 2
in. H2O.
Battery 10-year Lithium CR2032 battery retains the following data for a maximum of
10,000 hours during power outages: control programs, editable properties,
schedules, and trends.
Protection Built-in surge and transient protection for power and communications in
compliance with EN61000-6-1.
Incoming power and network connections are protected by non-replaceable
internal solid-state polyswitches that reset themselves when the condition that
causes a fault returns to normal.
The power, network, input, and output connections are also protected against
transient excess voltage/surge events lasting no more than 10 msec.
To protect against large electrical surges on serial EIA-485
networks, place a PROT485 at each place wire enters or exits the building.
BT485 connector You attach a BT485 (not included) to a controller at the beginning and end of a
network segment to add bias and to terminate a network segment.
Air conditioning equipment will provide safe and reliable service when operated within design specifications. The
equipment should be operated and serviced only by authorized personnel who have a thorough knowledge of
system operation, safety devices, and emergency procedures.
Good judgment should be used in applying any manufacturer's instructions to avoid injury to personnel or damage
to equipment and property.
Failure to follow this warning could cause personal injury, death, and/or equipment damage.
Disconnect all power to the unit before performing maintenance or service. Unit may automatically start if power is
not disconnected.
materials such as mercury contactors.
Follow all local, state, and federal laws regarding disposal of equipment containing hazardous
Mount the VVT Bypass II on the bypass duct damper actuator shaft. For service access, allow at least 1 foot (.3 m)
of clearance between the front of the controller and adjacent surfaces.
To disconnect and mount the controller and actuator separately
Disconnect the actuator from the controller by inserting a screw driver in the slot on the back of the VVT Bypass II
and pressing the tab. The actuator cable or an attached extension cable must connect to the controller's
port.
1 Turn the damper shaft to fully close the damper.
2 Mount the controller to the VVT terminal by sliding the clamp assembly onto the damper shaft.
7 Hold down the actuator damper release button and rotate the damper from fully closed to fully open. If the
damper traveled less than 90 degrees, do the following to set the actuator's fully open position:
a) Loosen the appropriate stop clamp screw. See figure below.
b) Move the stop clamp until it contacts the
edge of the actuator cam.
c) Tighten the screw.
8 Hold down the actuator damper release button, rotate the damper to verify that it fully opens and closes, then
release the button.
9
10 Connect the tube provided to the controller's
connector. Using 1/4" poly tubing, connect the other end
to a duct static pressure probe (for example, Dwyer Instruments part #A-491, or the equivalent, for a 6”
length probe) located in the supply air duct downstream of the bypass damper, but before the first branching
of ductwork.
Tubing should be at least 2 ft. (.61 meters) long for stable airflow measurement. The combined high
and low tubing length should not exceed 16.4 ft. (5 meters) in order to ensure accurate measurements.
connector to open space for plenum return or to a room space if using ducted
•The VVT Bypass II is powered by a Class 2 power source. Take appropriate isolation measures when mounting
it in a control panel where non-Class 2 circuits are present.
• Carrier controllers can share a power supply as long as you:
• Maintain the same polarity.
• Use the power supply only for Carrier controllers.
Do not apply line voltage (mains voltage) to the controller's ports and terminals.