Sequence Of Operation - KMC Controls KMCConquest FlexStat BAC-19 Series Sequence Of Operation

SEQUENCE OF OPERATION:

1. Occupancy: The occupancy mode follows the internal schedule. If motion
(optional) is not sensed within the standby timer during occupied mode,
the unit goes into standby mode until motion is sensed again.
2. On/off fan: When the fan mode is set to Auto and heating, cooling or
economizer is called for, the fan starts. Once the space temp returns to
setpoint, there is no call for heating, cooling nor economizer and the
fan-off-delay expires (2 minutes), the fan shuts off. During the occupied
and standby modes, the fan output is energized any time the fan mode is
set to On.
3. When the fan starts, if the normally closed fan status switch (optional)
doesn't open within 10 seconds, all heating, cooling and economizer
outputs are deenergized.
heating/cooling/economizer outputs remain disabled until the fan status
switch opens.
4. Modulating heating: As space temp drops below the heating setpoint, the
heating valve modulates open.
heating setpoint, the heating valve modulates closed. If the fan is set to
Auto, the valve is held shut until the space temp drops below the heating
setpoint minus the heating span at which point the valve opens and
follows the normal sequence.
5. Modulating Cooling: As space temp rises above the cooling setpoint, the
cooling valve modulates open.
cooling setpoint, the cooling valve modulates closed. While economizing,
the cooling valve is held shut the first 50% of the cooling span above the
cooling setpoint and then modulates open. If the fan is set to Auto, the
valve is held shut until the space temp rises above the cooling setpoint
plus the cooling span at which point the valve opens and follows the
normal sequence.
6. Staged heating: As space temp drops below the heating setpoint minus
the heating span, heating stage 1 is energized. If the space temp remains
below the heating setpoint minus the heating span for the stage delay,
heating stage 2 is energized. As the space temp rises above half of the
heating span below heating setpoint, stage 2 heating is deenergized. As
the space temp rises above the heating setpoint, heating stage 1 is
deenergized.
7. Staged cooling: As space temp rises above the cooling setpoint plus the
cooling span, cooling stage 1 is energized if the minimum off time has
been met. If the space temp remains above the cooling setpoint plus the
cooling span for the stage delay, cooling stage 2 is energized after
HTG VLV
100
AUTO
FAN
0
HTG SPAN
-2F
STAGE 1
STAGE 2
(STAGE
DELAY)
2.0F
STAGE 1
CLG
SP
© 2020 KMC CONTROLS, INC.
BAC-19xxxx FlexStat Sequence of Operation and Wiring Guide
Roof Top Unit with On/Off Fan,
Modulating and 2-Stage Heating and Cooling,
Economizer, and Humidity, Motion and CO2 Sensors
Model: BAC-19xx63C(E)
The fan output remains enabled and
As the space temp rises toward the
As the space temp drops toward the
MODULATING VALVE OPERATION
CLG VLV
AUTO
FAN
CLG SPAN ROOM
TEMP
HTG CLG +2F
INCREASE
SP SP
HEATING STAGES OPERATION
STAGE 2
STAGE 1
ROOM TEMP INCREASE
1.0F HTG
SP
COOLING STAGES OPERATION
STAGE 2
STAGE 1
STAGE 2
(STAGE
DELAY)
ROOM TEMP INCREASE
1.0F 2.0F
19476 INDUSTRIAL DR.
DRAWING TITLE:
NEW PARIS, IN 46553
PHONE: 574.831.5250 CREATION DATE:
FAX: 574.831.5252
ensuring its minimum off time. As the space temp drops below half of the
cooling span above cooling setpoint, stage 2 cooling is deenergized. As
the space temp drops below the cooling setpoint, cooling stage 1 is
deenergized.
8. Economizer: During occupied mode, if outside air temp (OAT) drops
below the economizer enable temp and there is a call for cooling, econ
mode is enabled. Econ mode is disabled if OAT rises 1 deg above the
econ enable temp. While economizing, the outside air damper (OAD)
modulates to maintain discharge air temp (DAT). As space temp rises
above the cooling setpoint, DAT setpoint resets from the space temp to
the minimum DAT. While economizing, the OAD is open to the greater of
the minimum damper position or DAT control. The OAD is shut during
unoccupied mode and any time the fan is off.
9. If the space humidity (optional) rises above the dehumidification setpoint,
the cooling valve is opened 100%. Cooling stage 1 is energized if the
minimum off time has been met. If the humidity remains high for the stage
delay and cooling stage 2's minimum off time has been met, cooling stage
2 is energized. The heating valve and staging then follows their normal
operation to maintain the COOLING setpoint. Once the space humidity
drops below the dehumidification setpoint minus its span, dehumidification
ceases and the heating and cooling valves and staging resume normal
operation.
10. In Basic Demand Control Ventilation (DCV), the OA damper opens 100%
as the CO2 level rises above the CO2 setpoint. As the CO2 level drops
below the CO2 setpoint minus the CO2 deadband, the damper
relinquishes to previous control.
11. In Standard DCV, the OA damper modulates from 0% open as the CO2
level rises from the CO2 base level +200 ppm to 100% open at the CO2
base level +600 ppm.
12. When both CO2 and economizer control are enabled, the damper
responds to the greater of CO2 or economizer control.
ROOM TEMP
MIN DAT
CLG
SP
MOD DEHUMIDIFICATION OPERATION
HTG VLV
100
AUTO
FAN
0
HTG SPAN
-2F
2 STAGE DEHUMIDIFICATION OPERATION
STAGE 2
STAGE 1
STAGE 2
(STAGE
DELAY)
HTG SPAN
-2F
ON
AUTO
OFF
HTG SPAN
-2F
20
FILENAME: KR19001-2
1/2/2020
ECONOMIZER DAT SETPOINT
CLG SPAN ROOM
TEMP
+2F
INCREASE
CLG VLV
100
0
ROOM TEMP DEHUM DIFF ROOM HUM
INCREASE INCREASE
CLG -5% DEHUM
SP SP
STAGE 1
STAGE 1
STAGE 2
STAGE 2
(STAGE
STAGE 1
DELAY)
ROOM TEMP DEHUM DIFF ROOM HUM
INCREASE INCREASE
CLG -5% DEHUM
SP
SP
FAN OPERATION
AUTO AUTO
(ECON)
ON
CLG SPAN ROOM
TEMP
HTG CLG +2F
INCREASE
SP SP
AG200123C