Technical Guidance Note 1

TOPIC: Off-the-shelf PCB

ISSUE: 3

REVISION DATE: 27.1.98

PREVIOUS REVISION DATE: 20.9.94

BACKGROUND: A supplier of instrumentation to the industry uses EMC approved PC's with an off-the-shelf PCB that fits into the expansion slot.

PROBLEM: Does the PCB require EMC approval or does the PC + PCB require approval?

GUIDELINES: The implication of the question that the PCB is marketed as a separate item from the PC and is probably not produced by the same manufacturer. Therefore, the computer manufacturer can have no control over the expansion boards that are fitted. The add-on board presents a risk of compromising the basic EMC performance of the PC.

As far as meeting the essential requirements of the EMC directive are concerned, there is no difference between somebody purchasing a board and plugging it into a computer and somebody buying a new washing machine and plugging it in to the mains. In both cases, the general consumer should be confident that the new piece of equipment purchased will not cause interference and will operate satisfactorily in the electromagnetic environment for which it is intended.

Disclaimer
No responsibility or liability can be accepted by the EMC Test Laboratories Association or any of its officers or members for the contents, specifications and/or advice referred to or contained in this Technical Memorandum and/or action taken as a result of information contained in this Technical Memorandum. Note that:
1. The Association is not by supplying this Technical Memorandum providing professional advice or guidance to any specific party on any specific matter and no legal relationship is created by the provision of this Technical Memorandum.
2. Parties should take specific advice when dealing with specific situations and consult their own professional advisors in this regard.
3. Members are free to deviate from the above guidelines where they think it appropriate, unworkable, or not commercially viable. Under these circumstances, the EMCTLA Secretariat should be informed of the reasons for the deviation so that the matter can be reviewed.