Input Attributes - Metasys - LIT-12012070 - Field Device - VAV: Variable Air Volume Controller

Air Handling Unit Reset Application Note

Brand
Metasys
Product name
VAV: Variable Air Volume Controller
Document type
Application Note
Document number
LIT-12012070
Revision date
2018-03-01
Language
English
Table 1. Input Attributes
Input Attribute Description

DAPSP-LV

The discharge air static pressure setpoint last value is 1.0 in. W.C. (AV). This is the current calculated discharge air static pressure setpoint, for monitoring only.

DATSP-LV

The discharge air temperature setpoint last value is 55.0°F (AV). This is the current calculated discharge air temperature setpoint, for monitoring only.

FANOFFPRESS-SP

The fan off pressure setpoint default is 0.2 in. W.C. (AV). This is the supply fan off static pressure setpoint. It allows you to see the setpoint fall and minimize alarm sounds when the AHU is turned off.

FANOFFT-SP

The fan off temperature setpoint default is 80.0°F (AV). This is the supply fan off discharge air temperature setpoint. It allows you to see the setpoint rise when the AHU is turned off.

FANSTARTPRESS-SP

The fan start pressure setpoint default is 0.7 in. W.C. (AV). This is the starting discharge air static pressure setpoint when the fan starts.

FANSTARTT-SP

The fan start temperature setpoint default is 65.0°F (AV). This is the starting discharge air temperature setpoint when the fan starts.

FIXEDP-SP

The fixed pressure setpoint default is 1.0 in. W.C. (AV). This is the fixed discharge air static pressure setpoint when the application is in the winter mode.

FIXEDT-SP

The fixed temperature setpoint default is 55.0°F (AV). This is the fixed discharge air temperature setpoint when the application is in the summer mode. Increase this setpoint for very humid climates.

MAXPRESS-SP

The maximum pressure setpoint default is 1.3 in. W.C. (AV). The application adjusts the discharge air static pressure setpoint as high as this maximum setpoint.

MAXT-SP

The maximum temperature setpoint default is 65.0°F (AV). The application adjusts the discharge air temperature setpoint as high as this maximum setpoint.

MINPRESS-SP

The minimum pressure setpoint default is 0.15 in. W.C. (AV). The application adjusts the discharge air static pressure setpoint as low as this minimum setpoint.

MINT-SP

The minimum temperature setpoint default is 55.0°F (AV). The application adjusts the discharge air temperature setpoint as low as this minimum setpoint.

PRESSREQ-O

The pressure request output default is the total number of boxes requiring an increase in static pressure. This is for monitoring only and should not be written (AV).

REQPRESS-SP

The VAV pressure requests setpoint default is 2 (AV). When the number of pressure requests is equal to this setpoint, the application is in the hold pressure mode. When the number of pressure requests is greater than this setpoint, the application is in the respond pressure mode. When the number of pressure requests is less than this setpoint, the application is in the trim pressure mode. This allows you to manage rogue zones. Use care when setting your value; as your value increases, you are less likely to meet your zone temperature setpoint.

REQTEMP-SP

The VAV temperature requests setpoint default is 2 (AV). When the number of temperature requests is equal to this setpoint, the application is in the hold temperature mode. When the number of temperature requests is greater than this setpoint, the application is in the respond temperature mode. When the number of temperature requests is less than this setpoint, the application is in the trim temperature mode. This allows you to manage rogue zones. Use care when setting your value; as your value increases, you are less likely to meet your zone temperature setpoint.

RESPONDPRESS-SP

The respond pressure setpoint default is 0.06 in. W.C. (AV). This is the amount that the application needs to add to the last value of the discharge air static pressure setpoint when the application is in the pressure respond mode. When this value adjusts, the respond setpoint is often greater than the trim setpoint.

RESPONDT-SP

The respond temperature setpoint default is 4.0°F (AV). This is the amount that the application needs to add to the discharge air temperature setpoint when the application is in the temperature respond mode. When this value adjusts, the respond setpoint is often greater than the trim setpoint.

SF-S

This is the supply fan status (BI). It should be mapped to your supply fan status point in your local field controller. For multiple supply fans, additional code is necessary to consolidate the fan status.

SUMWINT-S

The summer and winter mode default is summer (BV). This is the result of a separate LCT process monitoring the outside air temperature as compared to a setpoint (default 65°F with a 5°F differential). This is for monitoring only and should not be written. The winter mode is State 0, and the summer mode is State 1.

TEMPREQ-O

The temperature request output default is the total number of boxes requiring a decrease in discharge air temperature. This is for monitoring only and should not be written (AV).

TRIMPRESS-SP

The trim pressure setpoint default is 0.04 in. W.C. (AV). This is the amount that the application needs to subtract from the last value of the discharge air static pressure setpoint when the application is in the pressure trim mode.

TRIMT-SP

The trim temperature setpoint default is 2.0 (AV). This is the amount that the application needs to subtract from the discharge air temperature setpoint when the application is in the temperature trim mode.

OCC-S

The occupancy schedule default is occupied (MV). This is the occupancy schedule point in the field controller.

WC-C

The warmup/cooldown command default is normal (MV). This is the warmup/cooldown command point in the field controller.