JOHNSON CONTROLS
102
FORM 145.05-NOM7
ISSUE DATE: 10/31/2019
SECTION 5 – SEQUENCE OF OPERATION
TABLE 19 - ACTIVE SAT SETPOINT DETERMINATION, ZONE TEMPERATURE
∆T
OC
OCC
COOL
∆T
OH
OCC
HEAT
∆T
UC
OCC
COOL
∆T
UH
OCC
HEAT
OCCUPANCY
MODE
UNIT MODE ACTIVE SP
Greater than
0.5°F
Occupied Occupied Cooling Low
1st stage cooling
setpoint
Greater than
1.5°F
Occupied Occupied Cooling High
2nd stage cooling
setpoint
Less than
-0.5°F
Occupied Occupied Heating Low
1st stage heating
setpoint
Less than
-1.5°F
Occupied Occupied Heating High
2nd stage heating
setpoint
Occupied
Occupied Standby (See
also Comfort Ventilation
on page 102)
None
Greater than
0.5°F
Unoccupied Unoccupied Cooling Low
1st stage cooling
setpoint
Greater than
1.5°F
Unoccupied Unoccupied Cooling High
2nd stage cooling
setpoint
Less than
-0.5°F
Unoccupied Unoccupied Heating Low
1st stage heating
setpoint
Less than
-1.5°F
Unoccupied Unoccupied Heating High
2nd stage heating
setpoint
Unoccupied Unoccupied Standby None
Comfort Ventilation
When “COMFORT VENTILATION” is selected, the
Unit Controller monitors the Supply Air Temp and
uses it to energize mechanical cooling or heating even
though the zone sensor satisfies the normal heating or
cooling demand. This prevents the space temperature
from getting out of bounds before mechanical heating
or cooling is energized.
This is usually used when there is a large demand for
outdoor air for ventilation. If the Supply Air Temp is
equal to or greater than the “OCC ZONE COOLING
SETPOINT” plus 5.0°F, the Unit Controller enters the
COMFORT VENT COOLING mode and initiate com-
pressor operation. If the Supply Air Temp is equal to
or less than the “OCC ZONE HEATING SETPOINT”
minus 5.0°F, the Unit Controller enters the COMFORT
VENT HEATING mode and initiate heating operation.
The Unit Controller terminates COMFORT VENT
mode if the Supply Air Temp is less than the “OCC
ZONE COOLING SETPOINT” minus 5.0°F for 5
minutes; the Supply Air Temp is greater than the “OCC
ZONE HEATING SETPOINT” plus 5.0°F for 5 min-
utes; or the unit switches into the OCCUPIED HEAT-
ING OR OCCUPIED COOLING mode as a result of a
space sensor demand for cooling or heating.
For this mode of operation to function, the following
parameters must be programmed into the Unit Control-
ler through the User Interface.
• OPTIONS key, UNIT DATA subsection: UNIT
TYPE must be set to CONSTANT VOLUME
• PROGRAM key, VENTILATION subsection:
“COMFORT VENTILATION must be USER
ENABLED
• SETPOINTS key, COOLING subsection: “OCC
ZONE COOLING SETPOINT” must be set
• SETPOINTS key, HEATING subsection: “OCC
ZONE HEATING SETPOINT” must be set
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