VCB-X Operator Interface SD
VCB-X CONFIGURATION
31
VCB-X Con
fi
guration Screens
signal change will be 10% per time period. At 4
˚
difference, the signal
change will be 8% per time period. By the time the difference is 1
˚
, the
signal change will be 2% per time period. With a Proportional Window of
2
˚
, if you are 2
˚
or more from setpoint, the amount of signal change will
be 10% per time period, and at 1
˚
from setpoint the change would be 5%
per time period. So, a larger proportional window allows for
fi
ner tuning
of the control signal to prevent overshooting.
Default is 10.0
ºF/5.55ºC.
Description
Minimum
Default
Maximum
Economizer Control
Rate
1 sec
10 sec
30 sec
Proportional Window
1.0ºF
0.10ºC
10.0ºF
5.55ºC
30.0ºF
16.6ºC
Con
fi
guration Screen #32 - Economizer
Voltage Output
VCBX Cnfg ID 101
Econo Voltage Output
Min Volts: 2.0 VDC
Max Volts: 10.0 VDC
Enter
a value between 0.0 and 10.0 VDC for the Economizer minimum
and maximum output voltage.
Defaults are 2 VDC Min and 10 VDC
Max.
Description
Minimum
Default
Maximum
Min Economizer Voltage
0
2
10
Max Economizer Voltage
0
10
10
Con
fi
guration Screen #33 - CO
2
Sensor
Installed
VCBX Cnfg ID 101
Co2 Sensor Installed
None
Use < Or > To Change
Select
Digital E-BUS
if you have an E-BUS CO
2
Sensor installed.
Select
Receive Broadast
if the CO
2
Sensor is attached to a separate device that
will broadcast the reading, e.g., GPC-XP Controller.
Default is None.
Con
fi
guration Screen #34 - Building Pressure
Control
VCBX Cnfg ID 101
Building Pr. Control
None
Use < Or > To Change
Building Pressure Control is available if expansion module EM1 has
been installed and con
fi
gured.
Default is None.
Available options are:
None
—No Building Pressure Control by this controller.
On/Off Exh Relay
—If an On/Off Exhaust Fan is being
used, select this option and con
fi
gure a relay output as
Exhaust Fan. If the building pressure rises above setpoint,
this relay will energize. This is Direct-Acting control.
Modulating Exh
—If the building pressure rises above
setpoint, a modulating signal will be used to control an
exhaust fan VFD or a modulating damper to maintain
setpoint. A relay con
fi
gured as Exhaust Fan can be used
to enable this device so that the modulating signal can
control it. This is Direct Acting control.
OA Damper
—Select if reverse acting Building Pressure
Control using the Outdoor Air Damper is required. If
the building pressure falls below setpoint, the OA Damper
(Economizer) signal will be used to modulate the OA
Damper to maintain setpoint. This is Reverse Acting
control.
Supply Fan
—Contact WattMaster Factory regarding this
reverse acting Building Control option. This should not be
used in most applications. This is Reverse Acting control.
Con
fi
guration Screen #35 - Building Pressure
Control Rate & Max Increment
VCBX Cnfg ID 101
Building Pr. Control
Rate: 10 Sec
Max Increment: 5%
The Building Pressure Control Rate is the time period between changes
to the Building Pressure Control signal.
Default is 10 seconds.
The
Maximum Increment is the maximum amount the Building Pressure
Control can change per control rate period.
Default is 5%.
Description
Minimum
Default
Maximum
Building Pressure
Control Rate
1 sec
10 sec
30 sec
Max Increment
1%
5%
30%
