BAC-120063CW-ZEC FlexStat
10
Installation and Configuration Guide, Rev. G
intervals) to an optional CSP-4702.
The Trend Viewer is available in the Main Menu to
view the (last 256 samples of) data in tabular format.
Software, such as KMC Connect or TotalControl, can
view the trend objects as graphs as well as change
the interval as desired.
The different sampling rates allow a “longer” or
“finer resolution” view of the trends. The default
sampling intervals can be changed by the user in
ADVANCED > DEVICE
.
NOTE:
The faster the sampling rate, the faster the
256 samples are filled and the values start
over.
NOTE:
The FlexStat menu allows setting of
intervals only in
multiples of 1 minute
(not
seconds). If you change a default “seconds”
interval in the menu, you will not be able to
set it back to the original without a factory
reset or BAS software.
Zone Hysteresis (Changeover)
In the Additional Setup menu, the Zone Hysteresis
value (AV102) is the number of controllers (above
50% of the total) required for “majority rule” in
changing heating/cooling modes for the RTU or
HPU. The default is 1. For an explanation of this
changeover setting option, see
.
NOTE:
Firmware earlier than R2.0.0.4 did not have
this option.
Zone Status
In the lower right of the home screen, smaller letters
show, in rotation:
• The detected number of connected zones of
SimplyVAVs.
• The number of zones calling for cooling.
• The number of zones calling for heating.
NOTE:
After power-up or restarting of the FlexStat
and/or SimplyVAVs, the zone numbers
require several minutes to show correct
values.
For more detailed information, under the Main
Menu, select
ZONE STATUS
to view the status of all
connected zones. Options for each zone’s values are:
• Call for Cooling
• Call for Heating
• No Call for Either
Sequence of Operation
NOTE:
The HPU and RTU sections of the
have some basic
generic information about HPU and RTU
operation.
The BAC-120063CW-ZEC FlexStat determines RTU/
HPU heating or cooling mode by “majority rule”
of the number of heating and cooling calls from the
SimplyVAV controllers. If the number of heating and
cooling calls is equal, the previous mode is main-
tained.
The
number of controllers above 50% of the total re-
quired for changeover
to the other mode is controlled
by
Zone Hysteresis
(in the Additional Setup menu).
For the default setting of
1
, a majority by
one
control-
ler will cause the mode to switch. For example, 8
controllers calling for heating versus 7 controllers
calling for cooling will change the RTU/HPU mode
from cooling to heating.
NOTE:
If Zone Hysteresis is changed to
2
, then
heating/cooling mode maintains the
previous mode until there are
two
more
zones needing the opposite mode than
those needing the current mode. Increasing
the number can be helpful if the system
seems to be switching modes back and
forth too quickly. The maximum hysteresis
value is 16.
NOTE:
Zone Hysteresis (Changeover) on page
In RTU/HPU heating mode, the heating setpoint and
the cooling setpoint are both set to 110°. In RTU/
HPU cooling mode, the heating setpoint and the
cooling setpoint are both set to 55°. If there is no call
for heating or cooling (all VAV boxes are satisfied),
the cooling setpoint is set to 110° and the heating
setpoint is set to 55°.
During a scheduled Off time, the RTU/HPU fan does
not run unless there is a call for heating or cooling.
• No Communication with a Zone (either there is a
communication problem with a zone or no zone
is connected)
The Zone Status screen also shows the Duct Status
pressure.
