2-Pipe 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. 3 Speed fan: When the fan mode is set to Auto and the water valve 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 its span, high
fan speed becomes the active speed.
begins to return to setpoint, the active fan speed drops to medium.
As the space temp further returns to setpoint, the fan speed switches
to low. As the valve closes, all fan speeds are deenergized. During
the occupied and standby modes, low fan speed is energized while
the valve is closed if the fan mode is set to On. The fan follows the
normal sequence above once the valve opens.
3. Modulating fan: When the fan mode is set to Auto and the water
valve opens, the fan starts at minimum fan speed. Once the valve is
fully open, as the space temperature deviates further from setpoint,
the fan speed increases until it reaches maximum fan speed. As the
space temperature begins to return to setpoint, the fan speed
modulates toward minimum fan speed.
speed until the space temp further returns to setpoint and the valve
closes. During the occupied and standby modes, the fan is energized
at minimum fan speed while the valve is closed if the fan mode is set
to On. The fan follows the normal sequence above once the valve
opens.
REHEAT -
CHW AVAILABLE
100
20
0
HTG SPAN
-2F
HW AVAILABLE
100
0
HTG SPAN
-2F
2-PIPE MODULATING VALVE OPERATION
HW AVAILABLE
100
20
0
HTG SPAN
-2F
© 2020 KMC CONTROLS, INC.
BAC-19xxxx FlexStat Sequence of Operation and Wiring Guide
2-Pipe Fan Coil Unit with Modulating and 3-Speed Fan,
Modulating and On/Off Valve, Electric Reheat,
and Humidity, Motion and CO2 Sensors
Model: BAC-19xx63C(E)
As the space temperature
The fan runs at minimum
ELECTRIC REHEAT OPERATION
ROOM
TEMP
HTG
INCREASE
SP
2-PIPE ON/OFF VALVE OPERATION
CHW AVAILABLE
CLG SPAN ROOM
TEMP
HTG CLG +2F
INCREASE
SP SP
CHW AVAILABLE
CLG SPAN ROOM
TEMP
HTG CLG +2F
INCREASE
SP SP
19476 INDUSTRIAL DR.
DRAWING TITLE:
NEW PARIS, IN 46553
CREATION DATE:
PHONE: 574.831.5250
FAX: 574.831.5252
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
cooling outputs are deenergized.
and heating/cooling outputs remain disabled until the fan status switch
opens.
5. Water evaluation mode: If the water supply temperature (WST) rises
more than 10°F (AV56, adjustable) above space temp, hot water is
said to be available.
adjustable) below space temp, chilled water is said to be available.
As the WST comes within 8°F (AV56, adjustable, minus 2°F) of space
temperature, neither hot nor chilled water are available. If the Water
Type is determined to be Unconditioned , the water evaluation mode
runs once every 6 hours for five minutes or until a valid water type is
determined, whichever is reached first.
6. On/off valve: On a call for heating or cooling with the appropriate
water present, the valve opens once the space temperature is more
than half the span away from the setpoint.
temperature is within 5% of the span of setpoint, the valve closes.
7. Modulating valve: As space temperature deviates from setpoint with
the appropriate water present, the 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 valve modulates closed.
8. Electric reheat: If electric reheat (optional) is present, on a call for
heating with chilled water present, the reheat output behaves as if
heating is called for with hot water present. With hot water present,
electric reheat is locked out.
2-PIPE WATER EVALUATION
CHILLED
-10F -8F
MAX FAN SPD
100
AUTO
0
HTG SPAN
-2F
3 SPEED FAN OPERATION
HIGH
MED
LOW
AUTO
OFF
HTG SPAN
-2F
9
1/2/2020 FILENAME: KF1940A-2
The fan output remains enabled
If the WST drops more than 10°F (AV56,
When the space
HOT
NONE
WATER TEMP
+8F +10F
INCREASE
SPACE
TEMP
MOD FAN OPERATION
MIN
FAN
SPD
AUTO
ON
CLG SPAN ROOM
TEMP
HTG CLG +2F
INCREASE
SP SP
AUTO
ON
CLG SPAN ROOM
TEMP
HTG CLG +2F
INCREASE
SP SP
AG200123C