Attributes (Economizer Availability) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 15.0

Controller Tool Help

Brand
Johnson Controls
Metasys
Product name
Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
15.0
Revision date
2022-11-18
Language
English

Table 1 describes the attributes used by the Economizer Availability module.

Table 1. Economizer Availability Attributes

Name

Type 1

Description

Default Value

Bypass Percent

 

Provides the percent of air passing through the coil that is unaffected by the coil [%]. This is used for the Model-Based Economizer Type.

20%

Discharge Air Temperature

 

Provides the effective discharge air temperature for the cooling coil. This is used for the Model-Based Economizer Type.

12 °C, 55 °F

ECON-AVAILABLE (Free Cooling Available)

G, V

Displays a value of True when increasing the volume of outside air can reduce the cooling coil load. This attribute contains a value of False when the volume of outside air should be at the minimum required for ventilation.

 

Economizer Type

 

Use to select the type of economizer logic.

Temperature&Enthalpy

Set Name: Free Cooling Method

ECONSWO-SP (Change Over Temperature)

 

Specifies the change over dry bulb temperature used to determine if free cooling is available for the Dry Bulb Temperature economizer option.

20 °C, 68 °F

Elevation

 

Contains the distance above or below sea level [m or ft]. This is used in the psychrometric calculations performed for Economizer Type = Temperature & Enthalpy or Model Based.

0 m, 0 ft

Hardware Free Cooling Available

 

Provides an input that can be used to determine whether the economizer is suitable or not. The failsoft property on this attribute is set to True. If this input becomes unreliable, the default value of Not Available is used. Hardware Free Cooling Available is typically connected to the ECON-EN hardware input (BI).

Not Available

Set Name: Not Available/Available

Minimum OA Percent

 

Provides the percent of maximum supply fan flow rate required for the minimum amount of ventilation air.

20%

Network Free Cooling Available

 

Provides an input to this module that can be used to determine whether the economizer is suitable or not. True means suitable and False means not suitable. The failsoft property on this attribute is set to True. If this input becomes unreliable, the default value of False is used. Network Free Cooling Available is typically connected to the ECON-EN Network Input.

False

OA Humidity

 

Provides the relative humidity of the outdoor air and is used when the Economizer Type is Temperature & Enthalpy or Model Based. OA Humidity is typically connected from a Network Input or hardware input (OA-H).

50.0%RH

OA Temperature

 

Contains the dry bulb temperature of the outside air.

25 °C, 77 °F

Return Air Humidity

 

Provides the relative humidity of the return air and is used when the Economizer Type is Temperature & Enthalpy or Model Based. Return Air Humidity is typically connected from the RA-H hardware input.

50.0%RH

Return Air Temperature

 

Provides the dry bulb temperature of the return air and is used when the Economizer Type is Temperature & Enthalpy or Model Based. Return Air Temperature is typically connected from the RA-T hardware input.

20 °C, 68 °F

Suitability Selection

 

Defines the method for determining the suitability. Suitability may be a function of network suitability, hardware suitability, or humidity and temperature.

Local Sensors

Set Name: Free Cooling Select

Supply Fan Status

 

Provides the operating status of air-handling unit supply fan. When the fan is off, ECON-AVAILABLE is immediately set to False. When the fan turns on, the conditions are immediately evaluated to determine the economizer status. Running = True, Off = False.

True

Unit Set

 

Specifies whether this module should operate in Metric or Imperial units.

SI, IP

Set Name: Unit Set

1 C - Configuration Mode Only, G - Default Element (Generated State, if appliable), SC - Simulation and Commissioning Modes Only, V - Calculated Value (Outputs)