Start-up
VVT Bypass II Controller
CARRIER CORPORATION ©2019
Installation and Start-up Guide
All rights reserved
23
Performing system checkout
Bypass damper
1
Verify the VVT Bypass II is securely fastened to the bypass damper shaft and duct work.
2
Verify duct air temperature sensor is installed at the inlet of the damper or in the air source supply duct
upstream of the bypass damper connection.
3
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.
4
Calibrate damper 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 Close
, then
verify that the damper is fully closed.
d)
Click
Damper Full Open
, then verify that the damper is fully open.
e)
Click
Zero Cal
to close the bypass damper and 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.
i)
Using a branch-tee, connect a magnehelic gauge to the
High
connector on the controller's airflow
sensor, then measure the static pressure. If the measured static pressure is different from the
Duct
Static Pressure
by ±.05 in. (+.012 kPa), click
Pressure Sensor Cal
, enter the measured value next to
the button, then click
Apply
.
j)
Remove the magnehelic gauge from the
High
connector, then reinsert the pressure tubing.
k)
Click
Automatic Control
to return the bypass to normal control.
Содержание VVT Bypass II
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