proto

economizer fan vfd freq sensor point

implements

economizer

Duct to access fresh outside air only for economizing, not ventilation

fan

Fan equipment or control point

freq

Occurrences per unit time

point

Data point such as a sensor or actuator

sensor

Point is a sensor, input, AI/BI

vfd

Variable-frequency drive

vfd-freq

VFD frequency measured in "Hz"