JOHNSON CONTROLS
107
SECTION 5 – SEQUENCE OF OPERATION
FORM 100.50-NOM12
ISSUE DATE: 04/02/2019
5
FlexSys Setup
• The settings listed below are unique to FlexSys
configured units. Descriptions of the specific se
-
quences can be found later in the section.
• Setpoints such as RAT cooling and RAT heating
and others are covered under the appropriate sec-
tion in this IOM.
• Unit type must be set to FlexSys in the OPTIONS-
UNIT DATA menu.
• Dew point reset must be set to User Enabled/User
Disabled in the PROGRAM-COOLING menu.
• Active slab control must be set to User Enabled/User
Disabled in the PROGRAM-COOLING menu.
• Mixed SAT setpoint must be set in the SET-
POINTS-COOLING Menu.
• Return air diff setpoint must be set in the SET-
POINTS-COOLING menu.
• Maximum bypass setpoint must be set in the SET-
POINTS-COOLING menu.
• Evaporator leaving air temperature high setpoint
must be set in the SETPOINTS-COOLING menu.
• Evaporator leaving air temperature low setpoint
must be set in the SETPOINTS-COOLING menu.
• Reset enthalpy setpoint must be set in the SET-
POINTS-COOLING menu.
Current Operating Mode
•
The current operating mode for a FlexSys config
-
ured unit is decided the same as for a VAV config
-
ured unit.
• In the Occ mode, the IPU board compares the RAT
cooling and RAT heating setpoints against the cur-
rent RAT to determine if there is a demand for cool-
ing or heating.
• In the Unocc mode, the IPU compares the unocc
zone cooling and unocc zone heating setpoints
against the current zone temperature to determine
if there is a demand for cooling or heating.
LD28132
FIGURE 56 -
FLEXSYS — OCCUPIED