All,
I am in review of construction and testing requirements for a product
suing UL 1740 - Robotics and Robotic Equipment. I am using this
standard in conjunction with ANSI RIA R15.06. The device is not
stationary; it is tethered and self-propelled. It is powered by a
universal input of 90-254 VAC, 50-60 Hz and it does produce secondary
voltages as high as ± 600 V DC. I hope someone here can clarify my
concerns about the requirements for wet locations vs outdoor. I
anticipate that this product could be used in any type of weather
although this has not been discussed with the client.
In UL 1740 the definition of a Wet Location is "Portions of an indoor
installation where occasional or continuous exposure to water or other
liquids is anticipated". UL 1740 has considerations such as reduced wet
contact voltage limits and a brief mention of enclosure tests for
spraying water, but no modification for safety spacings or any other
concern.
Outdoor use is only mentioned a few times, twice as footnotes in sheet
metal minimum thickness tables and once in the section for outdoor-use
tests where it refers to solely to requirements of UL 50. RIA R15.06
does mention specification of intended use & limits including outdoor in
terms of risk assessment.
I suppose it bugs me a little that there is so little attention paid to
the possibility of water in the environment (/I am aware of submersible
robotic vehicles being approved to this standard, although this is not
the case in this instance)/. Is it possible that the committee did not
cover this matter in detail because they thought the Risk Assessment
would take up the slack? The client is especially concerned about safety
and has actually suggested multiple levels of redundancy with regard to
isolation and insulation. My feeling is that I should at least apply
some of the wet location provisions.
Any insights or experiences that can be offered are much appreciated.
Thank you, ~Doug
--
Douglas E Powell
[email protected]
http://www.linkedin.com/in/dougp01
-
----------------------------------------------------------------
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.ieee-pses.org/emc-pstc.html
Attachments are not permitted but the IEEE PSES Online Communities site at
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
formats), large files, etc.
Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html
For help, send mail to the list administrators:
Scott Douglas <[email protected]>
Mike Cantwell <[email protected]>
For policy questions, send mail to:
Jim Bacher: <[email protected]>
David Heald: <[email protected]>
