ASME Y14.44-2008 - Reference Designations for Electrical and Electronics Parts and Equipment

Description

This Standard covers the formation and application of reference designations for electrical and electronics parts and equipment. The reference designations of this Standard are intended for uniquely identifying and locating discrete items on diagrams and in a set; for correlating items in a set; graphic symbols on diagrams; and items in parts lists, circuit descriptions, and instructions. This Standard includes three methods for forming and applying reference designations. (a) the unit numbering method (b) the location numbering method (c) the location coding method A complete reference designation may incorporate reference designations formed by the use of any of these methods at any level from basic parts to complete units. The unit numbering method has a long history of satisfactory use in all types of electrical and electronics equipment. The location numbering method and location coding method have been developed to permit a rapid physical location of items in large, complicated equipment featuring multiple use of many identical or closely similar items. These methods shall be applied in such a way that duplicate complete reference designations do not occur in a piece of equipment or system. Device function designations for power switchgear and industrial control use are not covered by this Standard. FIGURES......Page 5 FOREWORD......Page 6 CORRESPONDENCE WITH THE Y14 COMMITTEE......Page 8 1.6 Reference......Page 9 1.7 Definitions......Page 10 1 Typical Basic Reference Designations in a Diagram......Page 11 2 Socket Reference Designations and Markings......Page 12 4 Connector Designations for Plug-In Items......Page 14 6 Physical and Circuit Relationship of N-Designated Circuit Groups......Page 15 2.2.3 Identification of Items in a Unit Which Are Not in a Subassembly. 1......Page 16 9 Identification of Subassemblies and Parts of Units......Page 18 11 Application of Reference Designations to a Unit......Page 19 13 Typical First-Level Coordinate Number Assignment......Page 20 14 Use of Suffix Letter to Locate Surfaces......Page 21 15 Location Numbering Applied at Several Subdivision Levels......Page 22 16 Coordinate First-Level Breakdown......Page 23 20 Identifiable Rows and Columns......Page 25 21 Designation of Deposited Components on Hybrid Printed Circuits......Page 26 7 CLASS DESIGNATION LETTERS......Page 27 3 Reference Designation in a Typical Schematic Diagram......Page 13 8 A Typical Set......Page 17 18 Location Coding of Multiple Levels of Equipment......Page 24 A BLOCK NUMBERING METHOD......Page 29