Side-by-side reference

Understand the difference.

Compare the meaning, drawing context and source references of two entries. A similar graphic or shared abbreviation does not establish equivalence.

First referenceCompare with

DVFS

Symbols

Duty-standby ventilation fan selection

Assigns the available room ventilation fans to the documented duty and standby roles. Ventilation control coordinates the equipment that manages heat and air movement in an electrical room. A temperature request, a fan command and proof of airflow are separate signals, and the room design determines how they interact.

Drawing use: Schematic
Application: Installation & communications
Reference family: Manufacturer

A distinction that matters

A standby fan does not prove adequate airflow. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.

Full reference

VFAC

Symbols

Ventilation fan automatic changeover

Transfers the documented ventilation duty when the active fan becomes unavailable. Ventilation control coordinates the equipment that manages heat and air movement in an electrical room. A temperature request, a fan command and proof of airflow are separate signals, and the room design determines how they interact.

Drawing use: Schematic
Application: Installation & communications
Reference family: Manufacturer

A distinction that matters

Changeover conditions require the ventilation design. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.

Full reference

Follow the full entry for source drawings and the appropriate standard or selected product. Equipment previews show a manufacturer drawing where available, otherwise a 3D thumbnail.