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

MBP

Symbols

UPS maintenance bypass

A UPS maintenance bypass is a set of switches, usually input, output and bypass, that lets the load be connected directly to the bypass supply while the UPS is fully isolated. It is normally external to the UPS cabinet so that the UPS itself can be removed without disturbing the load wiring.

Drawing use: SLD
Application: Microgrid systems
Reference family: IEC / IEEE / ANSI

A distinction that matters

A maintenance bypass is external switching around the whole UPS; the static bypass is an internal electronic path.

Full reference

UPS VFI

Symbols

Online double-conversion UPS

In an online double-conversion UPS the load is always supplied by the inverter. The rectifier converts incoming AC to DC, the battery floats on the DC link, and the inverter produces a regulated output that is independent of input voltage and frequency variations. When the input fails, the battery simply takes over the DC link with no transfer.

Drawing use: SLD
Application: Microgrid systems
Reference family: IEC / IEEE / ANSI

A distinction that matters

An online UPS powers the load through the inverter all the time; a line-interactive UPS passes mains to the load and only inverts during disturbances.

Full reference

Original educational previews. Follow the source references on each full entry for the appropriate standard or selected product.