KMC Controls BAC-19 FlexStat Series - Motion;Occupancy Sensor Does Not Work; Temperature Reading Is Incorrect; Temperature Setpoint Is Not Maintained

BAC-19xxxx FlexStat Application Guide 20 AG200824A
Motion/Occupancy Sensor Does Not Work
• After an initial power-up or restart, the motion/
occupancy sensor requires about 30 seconds
before it will begin responding to motion.
• Using KMC software, check that the motion
sensor is enabled and detects motion.
• The FlexStat must be installed where there
is a clear view of typical trafc area (reliable
range is out to about 33 feet). Remove or move
obstacles. Reinstall the FlexStat in a more
optimal location if necessary.
• See the Motion Sensing and Troubleshooting
(Location) sections in the Room Sensor and
Thermostat Mounting and Maintenance
Application Guide.
• Connect remote motion sensors to an input
(requires custom programming).
• Using KMC software, check that the motion-
related objects (BI9, BV6, and MSV1) are not
congured as Out Of Service.
Temperature Reading Is Incorrect
NOTE: Fahrenheit decimal values are not
displayed by default but can be enabled
by setting Precision to 0.1 in the Display
Object’s Rotations tab. The size of
the digits, however, are considerably
reduced.
• After applying power for the rst time (or after
an outage), allow the FlexStat to self-calibrate a
half hour before verifying temperature reading.
• Check that the correct °F/°C temperature scale
is selected.
• Check that the sensor is properly mounted
in a proper location. See the Room Sensor
and Thermostat Mounting and Maintenance
Application Guide.
• Check that the temperature sensors are not
covered or blocked.
• Check for the correct remote temperature
sensor conguration.
• Using KMC software, check that AI1 and AV1
(space temp.) are not congured as “Out Of
Service.”
• See also Input Values Outside Expected
Range on page 19.
Temperature Setpoint Is Not Maintained
• Select Occupied mode from the Home Menu.
• Override the fan to On from the Home Menu.
• Check that the appropriate application is
selected.
• Check inputs and outputs.
• Check schedules.
• Check that room temperature is being sensed
correctly—see Time and/or Date Are Not
Correct on page 21.
• Check that the corresponding analog value
object (e.g., AV3, AV4) is not congured as Out
Of Service.
• In 2-pipe FCU applications, check the
changeover water temperature sensor and
wiring.
• If the HVAC system has trouble recovering
from the unoccupied setpoint to the occupied
setpoint during very cold weather, decrease the
amount of setback or adjust the schedule.
• If space temperature is overshooting the
setpoint or oscillating, try increasing the
proportional band by a degree. If the problem
persists, try increasing the integral value
slightly (up to 20%). If the problem still
persists, try setting the integral value to 0.
(The optimal integral value is dependent on
the characteristics of the particular space and
HVAC system.)