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

BP/ATS

Symbols

Bypass-isolation transfer switch

A bypass-isolation transfer switch combines an automatic transfer switch with a parallel manual bypass switch. The bypass can connect the load directly to either source while the automatic switch is withdrawn or isolated, so maintenance and testing can proceed without interrupting critical loads such as hospital or emergency circuits.

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

A distinction that matters

A bypass-isolation switch adds a manual path around the ATS; a plain ATS must be de-energised for maintenance.

Full reference

ATS

Symbols

Automatic transfer switch

An automatic transfer switch monitors the normal supply and, when voltage or frequency goes out of limits, signals the generator to start and transfers the load to the alternate source once it is ready. When the normal supply returns and is stable, it transfers back after a time delay. Most units use an open-transition break-before-make sequence.

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

A distinction that matters

An automatic transfer switch operates without an operator; a manual transfer switch needs someone to move it.

Full reference

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