Brian & PSNet,
IEC 60990 - Measurement of touch current and protective conductor
current - is the IEC standard that discussed the proper techniques for
measuring leakage current for proper protection of persons for most
applications (not medical, obviously).
This standard uses the well known body model plus deals with the
issues of hi frequency waveforms - both sinusoidal and non-sinusoidal - in
properly accounting for these effects under conditions of either
startle-reaction or let-go in determining the protection given by any
equipment. Many IEC standards have adopted the circuits and techniques
presented there.
The standard instruments for making these measurements seem to be
well known and widely used; altho I learned of the multipurpose TE3027 from
the interchange.
In addition to the above, IEC 60990 had an Annex G dealing with
Construction and application of touch current measuring instruments. The
committee was privileged to have an experienced measurement engineer as a
member and he contributed this very valuable section. This discussion
starts with Considerations for selection of components of the proper power
and inductance for resistors along with proper capacitors for these
circuits. It discusses metering, accuracy and calibration & accuracy and
summarizes confirmation records needed to show adequacy for the equipment in
the measurement taken. I recommend that anyone who wants to build such a
circuit get the standard and review this section.
You may, Brian, be familiar with the ongoing Touch Current
discussions we have been having at the IEEE PSES meeting over the last
several years. Most of these papers have been published as part of the
proceedings of these conferences.
I wish you good luck in developing your own broadly based
measurement system.
br, Pete
Peter E Perkins, PE
Convenor, IEC TC108/WG5 Touch Current measurement
Principal Product Safety & Regulatory Consultant
Tigard, ORe 97281-3427
503/452-1201 fone/fax
[email protected]
-
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
Graphics (in well-used formats), large files, etc. can be posted to that URL.
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:
Scott Douglas <[email protected]>
Mike Cantwell <[email protected]>
For policy questions, send mail to:
Jim Bacher: <[email protected]>
David Heald: <[email protected]>
