Peter
I have posted two items with in the last few days, One of which may have
touched on whether to CE mark or not but that was not the main emphasis
1) CE EMC/LVD requirements for a DC drive. What are the standards that
apply to a DC drive. I did mention that this device is an accessory so
perhaps this where the CE mark issues comes up. CE mark on or off the
product I still need to determine what standards apply.
2) Standards Harmonized to the EMC and LVD directive. In my struggle to
apply the product family standard EN60255 (published 1993) to a family of
protective relays I have had to resolve if the EMC and LV directive
portions of the standard meet the requirements of the two directives. I
have been introduce to the concept of a standard being "harmonized relative
to a directive". For EMC I understand that to be "approved by CENELEC and
published in the OJ"........... I was looking for definitive references
that would show if a standard is "harmonized either to the EMC or LV
directive"............
>>
On the subject of components.
If we are talking about a component that doesn't perform a "direct
function" such as a relay, an IC, or perhaps a CRT display, I agree.
However if the component fulfills a "direct function" - That is it
supports an intended use and is available to a user without further
modification other than supple configuration issues than I disagree.
I use as reference the 1993 Guideline on the application of Council
Directive 89/336/EEC....
A copy of "The New Draft Commission on EMC Guidelines" is available at
ftp://ftp.win-uk.net/pub/users/emc/newguide.html - Please refer to
section 6 "Application of the Directive to apparatus: components, finished
products, systems and installations" The example of given in 6.2.2 of a
monitor used in a PC system had resonance. The monitor provided a
"direct function" while the CRT component inside did not. The point being
that there is a practical point where the device although a component of a
larger system has a distinguishable function relative to the user and if
marketed this way requires the CE mark. They go on to include a PC card
such as a Modem in this interpretation. I believe my DC drive may be
interpreted in this way.
Of course this topic can be stretched in both directions depending on the
example. I have seen CE mark on Opto 22 style single point I/O (see
Grayhill.com), on OEM power supplies, on CT accessories for portable meters
etc. Here the direct function can be made but it is not as convincing.
Lately I feel like I have changed professions from Engineer to Lawyer with
these interpretations. I very much appreciate your input
Regards
Chris Wells
Sr Design Engineer , Cutler-Hammer
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Original Text
From: C=US/A=INTERNET/DDA=ID/peperkins(a)compuserve.com, on 4/30/97 9:54
PM:
Chris,
The following comments were posted on the PSNet. They seem to
apply to your components.
- - - - -
PSNet
Editorial, Educate Your Customers from Test & Measurement
World/April, 1997 by Martin Rowe, Technical Editor
A reader who works for a component manufacturer told me that his
customers want his company to place the CE marking on its components. (The
CE marking indicates compliance with European EMC and Low-Voltage
Directives.) The reader says his customers think that designing products
with CE-marked components will ensure that the products will meet the
standards. He also claims that should a product fail compliance testing,
the customer can blame failure on any non-CE marked components.
I'd like to inform that customer that components can't officially
carry the CE marking. The CE marking applies to systems and subsystems
available for sale to end users. Components are excluded.
Manufacturers shouldn't place all blame for testing failures on
component manufacturers. Even if the components in a design have excellent
EMC and safety characteristics, a product can still fail compliance
testing. Components can't compensate for a poor board layout, lack of
proper shielding, and improper grounding.
Another problem with putting a CE mark on components is that the
end user might assume that a board or system filled with CE-marked
components meets the requirements for the marking. Therefore, installing
CE-marked components in your product can be deceptive.
So what should this company do? Should the company place the CE
marking on its components, adhering to the belief in "Rule number one: the
customer is always right. Rule number two:see rule number one?" Should
the company lose sales because it insists in not lulling customers into a
false sense of security?
Perhaps the company should try to educate its customers. The
component manufacturer can explain to its customers why components can't
carry the CE mark. The company should encourage its customers to design
for EMC; its customers must understand that the burden for EMC and safety
compliance fall on them. The trick is to make it clear that the company
isn't just trying to pass the buck to the customer.
If your company busy components to build into its products, you
shouldn't insist that those components have the CE marking, and none
should. If your marketing department or upper management thinks that
having products loaded with the CE-marked components makes the products
better, tactfully inform them that they're wrong. If you want your
products to pass compliance tests, you'll have to design them with
compliance in mind.
- - - - -
Your components need to have a European test house safety mark on
them - from VDE or NEMKO or such. The test house will select the
appropriate standard that applies to your component. This takes care of
the safety issue for you.
EMC requirements cannot be applied to a bare component. EMC
requirements are for equipment. Your customers will be using the
appropriate EMC standards for their type of equipment. You do need to test
your component in a typical application to ensure that it doesn't
contribute to the emissions in any substantial way nor be particularly
susceptible to emissions. If you find that the component radiates or is
particularly susceptible, you need to indicate to your customers what they
need to do to meet the typical requirements - such as put it in a shielded
enclosure.
Your component should not be CE marked.
- - - - -
Peter E Perkins
Principal Product Safety Consultant
Tigard, ORe 97281-3427
+1/503/452-1201 phone/fax
p.perk...@ieee.org email
visit our website:
http://ourworld.compuserve.com/homepages/peperkins
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