Regarding the product safety issue, I have found there are five concerns:
1. Enclosure - rarely the rack has been relied on for enclosure of
(recognized) products.
2. Stability - predictable with measurement data but its easier to directly
test
3. Temperature - a difficult problem to predict. Components may not have been
certified for elevated internal ambients. Testing of a maximum configuration
can often be done.
4. Input current - when using power controls or strips, can generally be
assumed to be the sum of the components.
5. Leakage current - also can generally be assumed to be the sum of the
components.
Certification of the system is not generally needed although we have had to do
field certifications of systems ending up in Los Angeles.
You should have data that shows, for example by testing worst case
configurations or documenting the rationale for deciding, that what you ship
is safe.
Bob Johnson
ITE Safety
Knighten, Jim L wrote:
I am wondering what the industry experience is regarding basing EMC or
Safety
product certification on individual chassis (or subsystems/components) that
may comprise the product, vs. certification at the product level?
In particular, I have some products that are 40U racks containing
multiple
chassis, each of which is compliant and has its own certification. Currently,
product certification is done at the entire product level (i.e., rack) and
there is a product regulatory label on the overall product. I know that some
companies (names withheld) that appear to be certifying only at the chassis
level, rather at the ensemble product level.
For EMI, I know the physics teaches us that CE + CE does NOT equal CE
(i.e.
one compliant chassis combined with another compliant chassis does not assure
a compliant combination of the two chassis). I have war stories to
corroborate this.
For Safety, there are some tests (heating test is an example) that can
be are
run at the product level.
Country approval documentation requirements vary by country, but usually
there is requirement for a DoC, CB report, etc.
I get increasing pressure internally (economically driven) to declare
product
certification done if all the constituent chassis are compliant and certified.
What is the experience you guys have?
Thanks in advance,
Jim
__________________________
James L. Knighten, Ph.D.
EMC Engineer
Teradata Corporation
17095 Via Del Campo
San Diego, CA 92127
858-485-2537 – phone
858-485-3788 – fax (unattended)
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This message is from the IEEE Product Safety Engineering Society emc-pstc
discussion list. To post a message to the list, send your e-mail to
<[email protected]>
All emc-pstc postings are archived and searchable on the web at
http://www.ieeecommunities.org/emc-pstc
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Website: http://www.ieee-pses.org/
Instructions: http://listserv.ieee.org/request/user-guide.html
List rules: http://www.ieee-pses.org/listrules.html
For help, send mail to the list administrators:
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