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.
3 Speed fan: When the fan mode is set to Auto and either valve or
2.
economizer is called for, the fan starts on low speed. As the space
temperature deviates further from setpoint, the fan speed changes to
medium. As the space temperature passes the active setpoint
plus/minus its span, high fan speed becomes the active speed. As
the space temperature begins to return to setpoint, the active fan
speed drops to medium.
setpoint, the fan speed switches to low. As the active valve closes
and there is no call for economizer, all fan speeds are deenergized.
During the occupied and standby modes, low fan speed is energized
while both valves are closed if the fan mode is set to On. The fan
follows the normal sequence above once either valve opens.
Modulating fan: When the fan mode is set to Auto and either valve
3.
opens or there is a call for economizer, the fan starts at minimum fan
speed. Once the active valve or economizer is fully open, as the
space temperature deviates further from setpoint, the fan speed
increases until it reaches maximum fan speed.
temperature begins to return to setpoint, the fan speed modulates
toward minimum fan speed. The fan runs at minimum speed until the
space temp further returns to setpoint and the active valve or
economizer closes. During the occupied and standby modes, the fan
is energized at minimum fan speed while both valves and economizer
are closed if the fan mode is set to On. The fan follows the normal
sequence above once either valve or the economizer opens.
4. When the fan starts at any speed, if the normally closed fan status
switch (optional) doesn't open within 10 seconds, all heating and
HTG VLV
100
20
0
HTG SPAN
-2F
HTG VLV
100
0
HTG SPAN
-2F
MODULATING VALVE OPERATION
HTG VLV
100
20
0
HTG SPAN
-2F
© 2020 KMC CONTROLS, INC.
BAC-19xxxx FlexStat Sequence of Operation and Wiring Guide
4-Pipe Unit Ventilator with Modulating and 3-Speed Fan,
Modulating Valves, Outside Air Damper
and Humidity, Motion and CO2 Sensors
Model: BAC-19xx36C(E)
As the space temp further returns to
As the space
DEHUMIDIFICATION OPERATION
CLG VLV
100
0
ROOM TEMP DEHUM DIFF ROOM HUM
INCREASE INCREASE
CLG -5% DEHUM
SP SP
ON/OFF VALVE OPERATION
CLG VLV
ROOM
CLG SPAN
TEMP
HTG CLG +2F
INCREASE
SP SP
CLG VLV
CLG SPAN ROOM
TEMP
HTG CLG +2F
INCREASE
SP SP
19476 INDUSTRIAL DR.
DRAWING TITLE:
NEW PARIS, IN 46553
cooling outputs are deenergized. The fan output remains enabled
and heating/cooling outputs remain disabled until the fan status switch
opens.
5. Modulating valves: As space temperature deviates from setpoint, the
appropriate heating or cooling valve modulates open until it is 100%
open when the space temp is 50% of the span away from setpoint.
As the temperature drops within 50% of the span of setpoint, the
heating or cooling valve modulates to closed.
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%. The heating valve then
follows its 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
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.
13. When both CO2 and economizer control are enabled, the damper
responds to the greater of CO2 or economizer control.
ROOM TEMP
MIN DAT
CLG
MAX FAN SPD
100
AUTO
0
HTG SPAN
-2F
HIGH
MED
LOW
AUTO
OFF
HTG SPAN
-2F
14
ECONOMIZER DAT SETPOINT
CLG SPAN ROOM
TEMP
+2F
INCREASE
SP
MOD FAN OPERATION
MIN
FAN
SPD
AUTO
ON
CLG SPAN ROOM
TEMP
HTG CLG +2F
INCREASE
SP SP
3 SPEED FAN OPERATION
AUTO
ON
CLG SPAN ROOM
TEMP
HTG CLG +2F
INCREASE
SP SP
AG200123C