SAE J2221:2019 pdf free

SAE J2221:2019 pdf free.Standardized Symbols for Electrical Circuit Diagrams
This document uses a building -block approach to construct symbols. Fundamental symbol characters are assembled to form symbols that depict physical components. Components are shown installed on a fully operable machine in a quiescent state: engine and key off, shifter in neutral, and engine cold. The following example shows how symbol characters can be combined to depict an actual vehicle device.
EXAMPLE: A single pole relay or contactor consists of three main elements, a separate symbol character can depict each (see Figure 1):
Symbols and symbol characters can be positioned and oriented in the attitude that best conveys circuit information. The symbol characters are usually positioned in a cause-and-effect sequence (left-to-right or top-to-bottom) to convey functional inter-relationships (see Figure 2):
A relay for vehicle applications is protected by an integral enclosure, which is graphically depicted by a rectangular box symbol character. Adding the enclosure symbol character results in the following symbol (see Figure 3):
A vehicle relay includes terminals for connection to related circuit wiring. Symbol characters can be added to depict plug-in or threaded terminals. An enhanced relay symbol results (see Figure 4):
This Recommended Practice can be revised by adding information, without changing the existing standardized symbols.
Additions can include, but are not limited to:New fundamental symbol characters Explanatory clarifications.
Requests for Revision should be submitted to SAE per web site information found on page 1.
A change bar (l) located in the left margin is for the convenience of the user in locating areas where technical revisions,not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only.SAE J2221 pdf free download.