JOHNSON CONTROLS
162
FORM 100.50-NOM12
ISSUE DATE: 04/02/2019
SECTION 7 – PARAMETER DESCRIPTIONS AND OPTIONS
PUMPDOWN
This parameter is programmed through the PROGRAM key. If Pumpdown is USER ENABLED
at the end of the compressor system cycle the solenoid value to the expansion vales will close
and the compressor will continue to operate for 30 seconds or until the low pressure cutout
opens. This removes the refrigerant from the low side of the system. The choices are USER
ENABLED or USER DISABLED. If Pumpdown is ENABLED all compressor system will use
Pumpdown.
RETURN AIR ENTHALPY
This is the total heat content of the return air.
RETURN AIR HUMIDITY
This is the return air relative humidity.
RETURN AIR TEMP
This is the return air dry bulb temperature.
RETURN AIR TEMP
CURRENT
This is the temperature of the return air entering the unit.
RAT HEATING SETPOINT
On a VAV or FlexSys unit, the IPU board monitors the RAT HEATING SETPOINT. When the
return air temperature is 0.5 °F below this value the control switches into the Occupied Heating
mode.
RAT COOLING
SETPOINT
On a VAV or FlexSys unit, the IPU board monitors the RAT COOLING SETPOINT. When the
return air temperature is 0.5 °F above this value the control switches into the Occupied Cooling
mode.
RAT SETPOINT FOR
HIGH SAT
This parameter is programmed through the SETPOINTS key. When the Return Air
Temperature is equal to or LESS than this temperature the Active Supply Air Temperature
Setpoint on a Variable Air Volume Unit is set to the SAT HIGH SETPOINT.
RAT SETPOINT FOR
LOW SAT
This parameter is programmed through the SETPOINTS key. When the Return Air
Temperature is equal to or greater than this temperature the Active Supply Air Temperature
Setpoint on a Variable Air Volume Unit is set to the SAT LOW SETPOINT.
READY TO RUN COMP A
This means the minimum OFF time has been achieved and all the safety circuits are closed
and compressor A of the system is ready to be energized. The User Interface will display either
YES or NO.
READY TO RUN COMP B
This means the minimum OFF time has been achieved and all the safety circuits are closed
and compressor B of the system is ready to be energized. The User Interface will display either
YES or NO
READY TO STOP COMP A
This means the minimum ON time has been achieved and compressor A of the system is
ready to be de-energized. The User Interface will display either YES or NO.
READY TO STOP COMP B
This means the minimum ON time has been achieved and compressor B of the system is
ready to be de-energized. The User Interface will display either YES or NO.
REFRIGERANT TYPE
This parameter is programmed through the OPTIONS key and identifies the type of refrigerant
in the unit.
RETURN AIR BYPASS
ACTIVE SP
This is the position of the bypass damper by percent open the IPU board uses as the bypass
setpoint on a FlexSys unit.
RETURN AIR BYPASS
CURRENT
This is the position of the by-pass damper by percent open the IPU board uses as the Active
Bypass percent setpoint on a FlexSys unit.
RETURN FAN
PRESSURE ACTIVE SP
This is the current mixed air chamber pressure that the IPU board is trying to maintain.
RETURN FAN PRESS
CURRENT
This is the actual pressure in the mixed air chamber of the unit.
RETURN FAN OUTPUT
This is the Binary output from the IPU board to the Return Fan control system.
RETURN FAN STATUS
This is a Binary input into the IPU board that identifies the Return Fan is functioning.
SAFETY INPUT LPCO
This is the Binary input to the IPU board from the Low Pressure Cutout safety circuit. ON
means the safety circuit is normal and FAULTED means it has faulted. This parameter is
shown for each compressor system.
SAFETY INPUT CHAIN
This is the Binary input to the IPU board from the Compressor Safety Circuit Chain. This
includes the high pressure cutout, compressor motor protector, and the external overload or
circuit breaker. ON means the safety circuit is normal and FAULTED means it has faulted. This
parameter is shown for each compressor system.
TABLE 54 –
DEFINITIONS (CONT'D)