Read the protection code.

Understand ANSI/IEEE device-function numbers and common manufacturer suffixes for protection, switching and control. Find definitions, practical distinctions and supporting public references.

2200Symbols 155Protection functions 800General arrangement objects 6,095CAD file listings

Power distribution

AC circuit breaker

The device-function number identifying an AC circuit breaker.

Protection functions

Line switch

The device-function number used for a line-switching or disconnecting device in its documented application.

Protection functions

Read the drawing, not just the mark

Small details. Different meanings.

Understand symbols, equipment tags and function numbers—and know when a generic object needs a manufacturer drawing.

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