scope:

This Addendum provides additional requirements specified for rail transit applications over those published in IPC/WHMA-A-620C. It prescribes the practices and requirements for the manufacture of cable, wire and harness assemblies in rail transit industry, and it applies to Class 3 to ensure industry-specific high reliability and environmental adaptability.

This Addendum is used in conjunction with IPC/WHMA-A-620C.

For the purpose of this Addendum, if a conflict occurs between the English version and other versions of this document, the English version will take precedence.

This Addendum particularly supplements or replaces Class 3 requirements in IPC/WHMA-A-620C. Clauses not involved and requirements not mentioned, i.e., Class 1, 2 requirements, are subject to the corresponding provisions of IPC/WHMA-A-620C.

The clauses modified by this Addendum do not include subordinate clauses unless specifically stated, i.e., changes made to 1.7 do not affect 1.7.1, unless 1.7.1 is also addressed in this Addendum.

When a paragraph, e.g., the first paragraph in 15.1 of this Addendum, refers to an entire section, i.e., section 15, it's the Responsibility of the Addendum users to determine which clauses from that section are used from IPC/WHMA-A-620C and which clauses are covered by this Addendum.

Tables/Figures, including newly added as well as original or modified from IPC/WHMA-A-620C, in a section in this Addendum are numbered from "1R", e.g., Figure 3-1R, 3-2R, Table 3-1R, 3-2R in section 3.

This Addendum does not specify frequency of in-process or frequency of end-product inspection. No limit is placed on the number of Process Indicators or the number of allowable repair/rework of defects. Such information should be developed with a SPC plan (see IPC-9191). Whenever special process is involved, e.g. soldering, crimp, ISO/TS 22163 and relevant documents shall apply.