Doug, and PSNet
The UL Component Recognition program clearly indicates that these
components are not complete in themselves and are intended to be
incorporated into finished equipment which is to be UL Listed. This UR
program has been set up to help component manufacturers begin the UL
investigation process in order to simplify the UL Listing of the finished
equipment by their customers. It would be a real pain if we had to
reinvestigate each component every time a product was evaluated for listing
(&, in fact, that is what UL also wants to avoid). Some things cannot be
evaluated at the component level - enclosures, for instance... so UL
includes Conditions of Acceptability/Engineering Considerations in the
component UL Report to which the UL engineer refers whenever the component
is included in the final equipment. As an equipment manufacturer you
should get these CofA's from your component suppliers to insure that you
have met each one in the application of the component.
Having chased these CofA's as a routine part of the safety
evaluation and certification of equipment, it is apparent that many
component manufacturers are not yet ready to easily provide such
information... they should provide you with a copy of the first few pages
of their UL Report which includes the models covered as well as the CofA...
UL, too, could do a better job of publicizing the common CofA's for
various components in the UL Yellow Books (there are some for a few
components)...
UL will, however, work with component manufacturers in some ways
that are cross current to getting the job done... I remember the project
in which the UL engineer stated that all the Power Supply tests would have
to be done in the end product... we were quite surprised as this is not
common... seems the PS manufacturer couldn't quite get all the work done
in time so he didn't do any testing... the UR only meant that the
construction had been examined,- spacings measured, etc... the CofA
clearly stated that all the testing was to be done in the final
equipment... very frustrating, (If we had only known beforehand)....
So, get your CofA's and know where you are going and what you have
to do to finish the work...
oh, by the way... you should include the CofA's in your CE marking
Technical File if you are relying on the UR mark in any way to show
compliance for the EU...
:>) br, Pete
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Peter E Perkins
Principal Product Safety Consultant
Tigard, ORe 97281-3427
+1/503/452-1201 phone/fax
[email protected] email
visit our website:
http://ourworld.compuserve.com/homepages/peperkins
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