Start-up
VVT Bypass II Controller
CARRIER CORPORATION ©2019
Installation and Start-up Guide
All rights reserved
24
l)
Enable the air source’s heating and cooling outputs using one of the following methods:
• Reconnect the air source controller’s output wiring at the unit.
• In the i-Vu® or Field Assistant tree, select the RTU Open controller. Go to
Properties
>
Control
Program
>
Configuration
>
Service Configuration
>
Service Test
, then disable
Service Test
and
Fan
Test
. Make sure all other outputs under
Service Test
are disabled.
CAUTION
Pressing the actuator release button and moving the damper or disconnecting the actuator
ribbon connector while the bypass controller is powered will cause the damper position to be out of
calibration. To recalibrate the damper position, you must perform steps 4c and 4d above or power cycle the
controller.
Variable frequency drive (VFD)
1
Verify that the controller's
VFD/ACT
output wiring is correctly connected to the VFD and that the VFD is
configured for a 0-10 Vdc control signal.
2
In the i-Vu® or Field Assistant tree, select the Bypass controller. Go to
Properties
>
Control Program
>
Unit Configuration
, then verify that
Control Device Type
is set to
VFD
.
3
Verify duct air temperature sensor is installed in the air source supply duct.
4
Verify that the high pressure tubing from the controller's airflow (pressure) sensor is connected to the
duct static pressure probe downstream of the bypass damper. Then verify that the low pressure
connector is not blocked.
5
Calibrate the VFD and pressure sensor:
a)
Disable the air source heating, cooling, and fan outputs using one of the following methods:
• Physically disconnect the air source controller’s output wiring to the unit.
• In the i-Vu® or Field Assistant navigation tree, select the RTU Open controller. Go to
Properties
>
Control Program
>
Configuration
>
Service Configuration
>
Service Test
, then enable
Service Test
.
Make sure all
other outputs under
Service Test
are disabled.
b)
Select the Bypass controller in the tree, then go to
Properties
>
Control Program
>
Unit
Configuration
>
Bypass Control
>
Details
tab.
c)
Click
Damper Full Open
, then verify the voltage at
VFD/ACT
and
Gnd
is 0 Vdc.
d)
Click
Damper Full Close
, then verify the voltage at
VFD/ACT
and
Gnd
is 10 Vdc.
e)
Click
Zero Cal
to zero the pressure sensor. When
Done
appears, click
Apply
.
f)
Enable the air source fan output using one of the following methods:
• Physically connect the air source controller’s fan enable wiring at the unit.
• In the i-Vu® or Field Assistant tree, select the RTU Open controller. Go to
Properties
>
Control
Program
>
Configuration
>
Service Configuration
>
Service Test
, then enable
Fan Test
. Make sure all
other outputs under
Service Test
are disabled.
g)
Select the Bypass controller in the tree, then go to
Properties
>
Control Program
>
Unit
Configuration
>
Bypass Control
>
Details
tab.
h)
After the static pressure has stabilized, make sure that
Target Damper Position
and
Duct Static
Pressure
are not locked and that
Target Damper Position
is >0% and <100%. You may have to
adjust the
Duct Static Pressure Setpoint
slightly to get the damper within this range.
Summary of Contents for VVT Bypass II
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