Hello EMC-PSTC Group,
Another real life drama. Hellllllp, I am being held hostage by the "how are
other companies getting away with it, they cannot possibly be testing their
total systems" people. Sorry for the length.
I am wondering how other companies address EMC compliance on large web-fed
printing press products. We can configure our product with different unwind
and rewind options. The unwind, rewind and dryer options can be from different
OEM manufacturers. It is my understanding that we have to test what we sell.
Our product is a web-fed printing press (transport) that contains an unwind
section, a middle/printhead section (which may comprise between two to three
sections/pieces) and a rewind section. The printhead section contains a dryer,
ink-jet printheads and a system/data controller. Printheads attach, via an
umbilical, to a print station cabinet that houses the ink and printhead
controls and is about 1-2 meters (3-6 ft) from the transport. The system
controller is a cabinet placed within the middle section. Data comes from the
data station cabinet that is away from the transport by 2-4 meters (6-12 ft).
This can comprise up to seven units.
This is my take (below contains some quotations and paraphrasing of Directives
and Standards):
Since our product is a combination of several apparatuses and intended to
operate together as a system to do a specific function, the EC sees the final
system as an apparatus, though the apparatus is physically large. As such, the
design and assembly of the product must comply with the essential requirements
of the EMC Directive. Compliance should take into account any reasonable
foreseeable environment in which we will operate the system.
Because our product is very large (it can be 8 to 13 meters (26 to 42 feet) in
length), and eventually will only come together on the customer's premises (OEM
units being drop shipped from the OEM manufacturer), bringing the
representative sample together every time for an EMC change is impractical.
Therefore, I tried to present the idea of testing "stand alone" assemblies
(apparatus) of the system to satisfy the EMC requirements for Europe, Canada
and the US. (My goal, by involving a Competent Body, was to get approval for
the "stand alone" assemblies approach.)
Since the standards show that the "end-item" needs tested, and we want to
reduce the number of "end-item" testing situations, this route would involve a
report/certification from an EMC Competent Body. A Competent Body
representative has informed me that the system needs to be tested once, with
all assemblies, for the conducted emissions. I thought that since it is
together we may as well do the other immunity and emission tests as well. This
can be done as an in-situ test.
We will test the representative sample (the system) once for a baseline,
supported by a report from an approved test house. We will test all
subassemblies ("stand alone" assemblies) for a baseline, supported by a report
from an approved test house. When we make an EMC change "we" can compare the
new baseline test results with the original baseline test results, along with
what changed, to decide if the representative sample will need tested with the
change. (The "we" are the Competent Body and us.)
In order not to put any restrictions on our product, as to the type of
establishment we can use it in, we are employing worst case testing. This
means that we will test radiated and conducted emissions to the light
industrial/commercial standards (e.g., EN 50081-1) and immunity to heavy
industrial standards (e.g., EN 50082-2). Per EN 55011:1991, Class B radiated
and conducted testing are requirements for Europe in situations that directly
connect to a low voltage power supply network which supplies buildings used for
domestic purposes. Class A radiated and conducted testing is suitable for use
in all establishments, other than domestic and those situations that directly
connect to a low voltage power supply network which supplies buildings used for
domestic purposes. (Note 2, section 4.3, EN 55011:1991 - - "Administrations
may allow, with whatever additional measures are necessary, the installation
and use of Class A ISM equipment in a domestic establishment or in an estab!
lishment connected directly to domestic electricity power supplies.") As an
alternative to Class B radiated and conducted testing, I would like to test to
Class A radiated and Class B conducted of EN 55 011, for use in all
establishments.
1. I believe this approach is viable. I am interested in your comments and I
will GREATLY appreciate any assistance you might offer.
2. How much of this is overkill?
3. Is Class A radiated and conducted testing sufficient for Europe?
(My thoughts: yes for heavy industrial; no for light industrial.)
4. With the power requirements of item four below, can this even be considered
light industrial?
5. Are there other avenues to pursue?
6. How do I find out what is practical regarding power drops in Europe (are
there voltage and current limits for a power drop)? Currently we are
requesting power drops for: 1. the data station (230 V ac, 1 ph, 14 A simplex
or 24 A duplex) and 2. the transport/dryer (230 V ac, 1 ph, 150 A; 480 V ac, 3
ph, 225 A).
Thank you in advance for your participation and information (and for my
release).
Best Regards,
David A. Sanders
Compliance Engineer
Scitex Digital Printing, Inc.
3000 Research Blvd.
Dayton, OH 45420-4099
tel: 937-259-3358
fax: 937-259-3655
E-mail: [email protected]
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