JOHNSON CONTROLS
160
FORM 100.50-NOM12
ISSUE DATE: 04/02/2019
SECTION 7 – PARAMETER DESCRIPTIONS AND OPTIONS
FURNACE 1A MODE
This is the current status of the modulating section of the modulating gas heat furnace. The
User Interface will display Off, Purge, Ignition, On-Low, On-High, Safety Trip, Safety Fault,
Safety Lockout, or Fault- I/O.
FURNACE 1B MODE
This is the current status of the non-modulating section of the modulating gas heat furnace.
The User Interface will display Off, Purge, Ignition, On, Safety Trip, Safety Fault, Safety
Lockout, or Fault- I/O.
FURNACE 2 MODE
This is the current status of the second heat exchanger section of a staged gas heat unit. The
User Interface will display Off, Purge, Ignition, On-Low, On-High, Safety Trip, Safety Fault,
Safety Lockout, or Fault- I/O.
FURNACE 3 MODE
This is the current status of the third heat exchanger section of a staged gas heat unit. The
User Interface will display Off, Purge, Ignition, On-Low, On-High, Safety Trip, Safety Fault,
Safety Lockout, or Fault- I/O.
GAS HEAT CAPACITY
This parameter is programmed through the OPTIONS key. This parameter is used to identify
the gas heat capacity installed in the unit. The options are 375 MBH, 750 MBH, or 1125 MBH.
HEAT ENTERING TEMP
This is the temperature of the supply air entering the staged heat section. This value is used to
initiate and terminate Supply Air Tempering when Staged Heat is installed.
HEAT LIMIT
TEMPERATURE
This parameter is programmed through the SETPOINTS key. This value determines the
maximum allowable Supply Air Temperature when heating is installed. If the temperature goes
above this setting the heat section is shut down.
HEATING CONTROL
OFFSET
This is the control band the unit is trying to maintain. The control band is the Active Se/-
the Heating Control Offset. If the temperature is below this band, additional heating is required,
if the temperature is above this band heating is decreased.
HEATING SAT
This parameter is programmed through the SETPOINTS key. On a VAV or FlexSys unit this
becomes the Active Supply Air Temperature Setpoint for heating operation. The IPU board
controls the heating option to try and maintain this temperature.
HEATING SYS STATUS
This is the current operating mode of the Heating Section. The display will show Normal -
Active, Normal - Inactive, Safety Trip, Safety Fault, Safety Lockout, User Disabled, or None.
HEATING SYSTEM TYPE
This parameter is programmed through the OPTIONS key. This parameter is used to identify
the type of heat installed in the unit. The options are None, Electric, Stage Gas, Modulating
Gas, Hot Water / Steam.
HW / STEAM FRZ STAT
This is the status of the hydronic heat freezestat. This is done through a Binary input to the IPU
board. The switch is open for normal operation and closed on failure. The User Interface will
indicate OK or FAULTED.
HW / STEAM HEAT -
VALVE POS
This is the output from the IPU board to the hydronic valve as percent open.
HW VALVE ACTION
This parameter is programmed through the PROGRAM key. This parameter controls the output
to the hydronic modulating valve. When the parameter is set to DIRECT the output is 0 volts
for off and 10 volts for full capacity. When the parameter is set to REVERSE the output is 10
volts for off and 0 volts for full capacity.
MAXIMUM BYPASS
This parameter is programmed through the SETPOINTS key. It establishes the maximum
allowable position of the bypass damper in a FlexSys unit.
MECH CLG LOCKOUT
TEMP
This parameter is programmed through the SETPOINTS key. When the outdoor temperature
is equal to or less than this temperature, the IPU board will prevent the compressors from
operating.
MINIMUM OA FLOW
SETPOINT
This parameter is programmed through the SETPOINTS key. When air measurement stations
are installed and the unit is not in the Occupied mode, this is the minimum allowable airflow.
MX SUPPLY AIR TEMP
This parameter is programmed through the SETPOINTS key. This becomes the Active Supply
Air Temperature Setpoint for a FlexSys unit when it is in the Occupied Cooling Without Bypass
mode.
FURNACE 1A MODE
APRX RATE
This is the approximate firing rate of the modulating gas heat section in MBH.
FURNACE 1A MODE
RELATIVE
This is the output from the IPU board to the modulating gas heat section in percent of full
capacity.
TABLE 54 –
DEFINITIONS (CONT'D)