KMC Controls FlexStat series Operation Manual page 13

Although BAC-12xxxx FlexStats do not have a built-
in CO sensor, they still have DCV control sequences
2
available. When DCV is enabled in the Damper
Setup menu of these models, IN9 is assumed to be
connected to an external SAE-10xx CO
space) sensor. 0–5 VDC on that input (configured
in the (Advanced) Inputs menu) will map to 0–2000
ppm. The output of the connected SAE-10xx must
also be configured to match the FlexStat's input (see
the installation guide for the appropriate SAE-10xx
model), and the FlexStat's IN9 pull-up resistor must
be set for 0–12 VDC (see the appropriate FlexStat
installation guide)! BAC-13xxxx/14xxxx FlexStats
also have the external sensor option, and if used, the
highest of the two readings (internal vs. external)
will be used to control DCV sequences. The CO
display (if enabled) also shows the highest of the two
levels. (Allow at least 15 minutes after installation for
the reading to stabilize.)
NOTE: Not all applications have a modulating
economizer option. Without a modulating
economizer selected, DCV will not appear
in any menus, but the (Advanced) CO
Sensor menu will remain and the CO
readings will still show on the display.
NOTE: An alarm is generated when the CO
too high for too long. See Alarms on page
NOTE: The various Outside Air (OA) % settings
available are the percentage that the OA
damper is open and not the percentage
of OA flow. These settings should be
measured and set accordingly.
NOTE: See the DCV section in the relevant
Sequence of Operation of the FlexStat
Application Guide for more information
about the modes and options described in
general terms here.
The three types of DCV configurations available
are:
• BASIC DCV—Provides simple DCV, modulat-
ing the outside air damper in direct response to
the current CO level with respect to its setpoint.
2
Basic DCV is much more energy efficient than no
DCV at all, while maintaining adequate IAQ (In-
door Air Quality). It is the easiest DCV method
to configure. However, where VOCs, radon, or
other pollutants become excessive during unoc-
cupied times (with no ventilation), the FlexStat's
Standard or Advanced DCV configuration is
recommended.
FlexStat
Outside Air
(duct or
2
Position
Component
• STANDARD DCV—When the BAC-13xxxx
settings are properly configured, this complies
ppm
with CA Title 24, Section 121(c). This would also
2
apply to a properly configured BAC-12xxxx with
a remote SAE-10xx CO
under most conditions, is somewhat less energy
efficient than Basic, but it enhances IAQ.*
*NOTE: The CO
2
ppm
2
level is
2
23.
Outside Air
Damper
Position
Component
• ADVANCED DCV—When the settings are
properly configured, this configuration complies
with CA Title 24, Section 121(c) and ASHRAE
Standard 62.1-2010 and follows guidelines by
Portland Energy Conservation, Inc. (PECI).
Although Advanced DCV is the most complex to
configure, it is more energy efficient than Stan-
dard while still optimizing IAQ.
13
100%
Basic DCV Configuration
DCV Signal
Damper
Component
to OAD
0%
CO CO
2 2
Base Setpoint
Space CO
sensor. Standard DCV,
2
sensors in the BAC-13xxxx series
2
FlexStats (as well as properly configured
SAE-10xx CO detectors) have been certified
2
to comply with CA Title 24, Section 121(c),
as well as sub-paragraph 4.F that specifies
accuracy will be maintained within
tolerance for a minimum of 5 years without
recalibration. See the data sheet for more
information.
100% Standard DCV Configuration
OA Full
DCV Signal
Component
to OAD
OA Area
0%
CO CO
2 2
Base Setpoint
Space CO
CO
2
Maximum
2
"Standard"
Signal
"Basic" Signal
CO
2
Maximum
2
Operation Guide, Rev. M