7
JOHNSON CONTROLS
FORM 145.05-SU2 (1207)
CONSTANT VOLUME
COOLING SUPPLY AIR TEMPERATURE CONTROL
This feature allows the unit to control the staging of
the compressors based on the difference between the
supply air temperature and the supply air temperature
set point.
Field Wiring
None required.
Programming
The following items must be programmed through the
“
Setpoints
” section of the User Interface:
•
“AC-S/A Temp En”
must be set to ON. The de-
fault is ON
•
“AC/Econ-S/A SP”
set point must be pro-
grammed. The default value is 55.0˚ F. This
is the supply air temperature the unit will try to
maintain.
C O O L I N G R E T U R N A I R T E M P E R AT U R E
CONTROL
This feature allows the unit to control the staging of
the compressors based on the difference between the
return air temperature and the return air temperature
set point.
Field Wiring
None required.
Programming
The following items must be programmed through the
“
Setpoints
” section of the User Interface:
•
“AC-R/A Temp En”
must be set to ON. The
default is OFF
•
“AC/Econ-R/A SP”
set point must be pro-
grammed. The default value is 75.0˚ F. This
is the return air temperature the unit will try to
maintain.
COOLING SUPPLY AIR AND RETURN AIR
TEMPERATURE CONTROL
This feature allows the unit to control the staging of the
compressor based on either the temperature difference
between the supply air temperature and the supply air
temperature set point and the return air temperature
and the return air temperature set point. When both are
selected the compressors will be cycled based on the
lesser of the two demands.
Field Wiring
None required.
Programming
The following items must be programmed through the
“
Setpoints
” section of the User Interface:
•
“AC-S/A Temp En”
must be set to ON. The
default is ON.
•
“AC/Econ-S/A SP”
set point must be pro-
grammed. The default value is 55.0˚ F. This
is the supply air temperature the unit will try to
maintain.
•
“AC-R/A Temp En”
must be set to ON. The
default is OFF.
•
“AC/Econ-R/A SP”
set point must be pro-
grammed. The default value is 75.0˚ F. This
is the return air temperature the unit will try to
maintain.
SUPPLY FAN OPERATION
This feature tells the unit if is has a constant volume or
variable volume supply fan.
Field Wiring
None required.
Programming
The following items must be programmed through the
“
Setpoints
” section of the User Interface:
•
“Fan-VAV/CV En”
must be set to CV. The de-
fault is VAV.
