se_industrial_whitepaper_increase_sccr.pdf
Best regards,
Rich
From: Ralph McDiarmid mailto:rmm.priv...@gmail.com> >
Sent: Tuesday, May 14, 2024 11:41 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] SCCR Rating Ques
Brian:
See the very last line of:
https://www.mouser.com/pdfDocs/littelfuse_industrial_whitepaper_increase_sccr.pdf
Best regards,
Rich
From: Ralph McDiarmid mailto:rmm.priv...@gmail.com> >
Sent: Tuesday, May 14, 2024 11:41 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG <mai
Could this number to used to select a suitable circuit breaker and so the
interrupting voltage is an important parameter?
The nameplate rating on the machine should be the information an electrician
needs during installation and selection of wire size and type.
Ralph
From: Brian
The IEC store has IEC TR 62368-2:2019 RLV for 553 Swiss Francs. Ouch.
From: John Woodgate
Sent: Wednesday, May 8, 2024 1:37 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 62368-1: To understand chapter 5.4.11
You can get 62368-2 from:
Brian, for a rigorous determination of creepage and of clearance you need to
also determine and assign:
1. Over-voltage Category ( affects Clearance )
2. Pollution Degree ( micro-environment affecting Creepage )
3. Basic (simple separation) or Reinforced (protective separation)
Hi Ralph,
Is this what you are looking for?
https://single-market-economy.ec.europa.eu/single-market/european-standards/
harmonised-standards_en
Greetings,
Bart
From: Ralph McDiarmid mailto:rmm.priv...@gmail.com>
>
Sent: woensdag 17 april 2024 19:04
To: EM
Can someone provide a link to this list. I have searched eur-lex.europa.eu
website without success.
Ralph
-
This message is from the IEEE Product Safety Engineering Society emc-pstc
discussion list. To post a message to
to use an average detector for radiated
emissions between 30 and 1000 MHz?
On 4/5/2024 6:39 PM, Ralph McDiarmid wrote:
I’m having trouble with “Of those disturbances above (L-20dB), where L is the
limit level in logarithmic units, the disturbance levels and the frequencies of
at least the six
That has been my experience with CB Scheme, E-mark, and product safety in the
USA using an NRTL. Namely, pick worst-case with justifications, talk with your
certifier, and reach an understanding. If they won't budge and insist on full
testing of every variant, move to another certifier who is
I'm having trouble with "Of those disturbances above (L-20dB), where L is
the limit level in logarithmic units, the disturbance levels and the
frequencies of at least the six highest disturbances shall be recorded."
Does this CISPR measurement methods standard expect you to record the six
NFPA can be viewed free online, however, CSA C22.1, C22.3, and C22.3 appear
to be by purchase only.
Ralph
From: Don Gies <2f2a08db2fba-dmarc-requ...@listserv.ieee.org>
Sent: Friday, April 5, 2024 11:20 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] GFCI Receptacles
Hi
And, NFPA provides free, online, read-only access to all their standards.
So does UL.
Ralph
From: Don Gies <2f2a08db2fba-dmarc-requ...@listserv.ieee.org>
Sent: Friday, April 5, 2024 11:02 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Fire codes related to batteries
Hi
Many product safety standards require vertical flame rating for polymeric
material forming part or all of the enclosure. I’m surprized it doesn’t
require V-0 or 5VA. It’s seems to be about containing a fire inside the
enclosure.
Ralph
From: emcl...@gmail.com
Sent: Thursday, March
Then again, what is the effective value of the 42Vpeak pulsed d.c. ? Does
it exceed the Vrms limit at your highest duty ratio? You mentioned a 0.01%
minimum on-time, but what is the maximum?
From: James Pawson (U3C)
Sent: Monday, February 26, 2024 5:38 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
standards is
already a simplification. See IEC 60479-1 and -2. You can find the free preview
of IEC 60479-1 here
<https://webstore.iec.ch/preview/info_iec60479-1%7Bed1.0%7Den.pdf> , with a
good high level discussion in the scope.
On Mon, Feb 26, 2024 at 2:26 PM Ralph McDiarmid mailto:rm
I suspect many of the standards committee have merely adopted the Vpeak
limit from other standards without giving it much thought. Note that
42.4Vpk is just root2 x 30Vrms. That seems to be all there is to it and I
doubt it's mere coincidence. (60Vdc/30Vrms/42.4Vpk found in several
standards)
An immaculate analysis and air-tight conclusion, as I see it.
From: James Pawson (U3C)
Sent: Monday, February 26, 2024 5:38 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] 61010-1 hazardous live classification
Hello all,
I hope this safety question is a fairly simple one for
In the 3rd edition of IEC 62368-1, it reads,
“Additional requirements for equipment having the capability to supply DC power
over
commonly used communication cables, such as USB or Ethernet (PoE), are given in
IEC 62368-3.”
Ralph
From: peterh...@aol.com
If you test that connector with the blunt test probe (aka finger probe)
using the procedure described in the standard and it does not touch the
connector pins (and you have minimum clearance) then your certifier should
reconsider the dielectric test level. Many standards still use basic and
Hi Lauren,
MCCB (molded case circuit breakers) get hot when they are run close to their
handle rating, even open bench. If installed in a panel (dead air space) at
40C ambient temperature, I would expect they would easily exceed 50C on
their molded case long before say 3 hours have expired
On Wed, Nov 1, 2023 at 1:20 PM John Woodgate mailto:j...@woodjohn.uk> > wrote:
Somewhere in all the Byzantine rules, there is a ban on applying the CE mark if
no Directive or Regulation that demands it applies to the product.
On 2023-11-01 19:58, Ralph McDiarmid wrote:
Furthermore,
What is meant by “safety information on the Declaration of Conformity”? A DofC
contains a list of applicable EU directives and standards. I’ve never been
asked to draft a DofC for signature with “safety information” in it.
Furthermore, I have not found anything document which says that you
The EMC standard with which I am familiar (CISPR11, EN55022) are well
written and provide examples of best practice setup and how to arrange
excess cable length. I suggest going over the standard with the test
technician at the EMC lab to better understand the requirement.
If it were my
" This incident serves to remind us that in our field of product safety, we
require the product to be safe even in the event of a failure of any single
component. "
Maybe better to claim "product safety compliant under any single-fault".
It's quite a reach and perhaps not appropriate to claim
if anyone uses their employer or private
business devices to use AI tools: the information used for questions
immediately and forever becomes public property.
-Original Message-
From: Ralph McDiarmid
Sent: Wednesday, October 11, 2023 2:08 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re
Obviously, even an "antiquated design with a single point of failure", gets
an air worthiness certificate by the FAA. However, LFP batteries need a
fault-tolerant battery management system and tons of testing called out in
UL1973 3rd edition. Not all aircraft need single-fault tolerance.
I
Here's what ChatGPT 3.5 says about fault-tolerance and general aviation
aircraft:
Fault-tolerance systems in general aviation aircraft can enhance safety, but
their inclusion is not mandatory for all such aircraft. The need for
fault-tolerance systems depends on several factors, including the
(519) 729-5704
"All animals except man know that the ultimate joy of life is to enjoy it." --
Samuel Butler
On Oct 10, 2023, at 14:15, Ralph McDiarmid mailto:rmm.priv...@gmail.com> > wrote:
Physicians have used AI (expert systems) in their offices for many yea
Which is another way of saying that ChatGPT and other similar AI are tools used
by professionals to assist with improving their productivity, but not something
to be used in lieu of a professional. (at least not in this decade). That
time may come, but I suspect engineering jobs are safe for
I would add that about 9 out of 10 power engineers I’ve worked with over the
years are equally confused with the “convention” of power factor and sign
convention of real and reactive power flow. Microelectronics engineers also
often get the sign convention wrong when considering current source
Very interesting demo of its capabilities.
I am wondering if the $20 per month version of ChatGPT might be worthwhile.
Ralph
From: Dan Roman <0d75e04ed751-dmarc-requ...@listserv.ieee.org>
Sent: Monday, October 9, 2023 7:21 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] AI &
“Even so, I do find them useful as a starting point for writing White Papers
and PowerPoint slides or procedural documents at the paragraph-level, for
internal distribution. “
I do the same. It’s useful now, even though not perfect, and AI is only going
to get better and that will happen
Best regards
Charlie
Charlie Blackham
Sulis Consultants Ltd
Tel: +44 (0)7946 624317
Web: https://sulisconsultants.com/
Registered in England and Wales, number 05466247
From: Ralph McDiarmid mailto:rmm.priv...@gmail.com> >
Sent: Friday, October 6, 2023 10:59 PM
To: EM
Heres what ChatGPT told me about this directive:
The General Product Safety Directive (2001/95/EC) in the European Union (EU)
is a legal framework designed to ensure the safety of consumer products
placed on the EU market. It sets out general requirements for the safety of
products,
Here’s what ChatGPT recommends:
In South Korea, to obtain KC (Korea Certification) registration for a Class III
radio device, you will need to follow a specific process to ensure your product
complies with the country's regulatory requirements.
Here are the general steps you should
eceive and determine some
information from the received signal then it would be “radio equipment” under
RED
Best regards
Charlie
Charlie Blackham
Sulis Consultants Ltd
Tel: +44 (0)7946 624317
Web: https://sulisconsultants.com/
Registered in England and Wales, number 05466247
From:
Given the reasoning you propose, your spectrum analyser, as an unintentional
radiator, should be out of scope of the RED. If it were, then all television
and radio receivers would also fall under the RED.
From: Amund Westin
Sent: Wednesday, October 4, 2023 10:51 AM
To:
I see that I had to set something up on the list server so that I can see my
own postings.
-
This message is from the IEEE Product Safety Engineering Society emc-pstc
discussion list. To post a message to the list, send your
Circuit simulation (Pspice or similar) would allow you to find highest
working voltage on each capacitor under normal and under single-fault
conditions including component tolerances and line voltage variation. In
this country, a nominal 347/600V service has voltage variation limits of
550V to
-
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
All emc-pstc postings are archived and searchable on the web at:
Brian,
As a good starting point, I recommend reading the following:
UL991 : Safety-Related Controls Employing Solid-State Devices
CSA C22.2 No. 0.8 : Safety Functions Incorporating Electronic Technology
There is functional safety analysis software available, but some may have a
hefty price
The phrase, “as to ensure that”, implies some testing would be needed for both
emissions and immunity. The directive doesn’t insist on testing, but to meet
the “essential requirements” testing would seem the only way to reinforce a
claim of compliance.
Ralph McDiarmid
(Vancouver)
From
The phrase, “as to ensure that”, implies some testing would be needed for both
emissions and immunity. The directive doesn’t insist on testing, but in order
to meet the “essential requirements” testing would seem the only way to
reinforce a claim of compliance.
From:
Anyone know the technical justification for the percent THD limit
calculation in clause 35.2 in UL1711 ?
Without HTML, the plain text reads:
THD (%) = 20 x e^(-0.000189(f-2800)) where f is the bandwidth in
Hz.
Seems a strange way to specify THD as a function of audio amplifier
I would only add that those details need to be consider during design, not
after the design.
Ralph
From: Douglas Nix <0bb8ff993b10-dmarc-requ...@listserv.ieee.org>
Sent: Wednesday, August 30, 2023 6:31 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] DFMEA Component
I wonder why industry is spending so much on EMC compliance. Is it because the
development teams are leaving this work to the final phase of the design, where
changes are expensive and schedules slip ?
Ralph
From: doug emcesd.com
Sent: Saturday, August 12, 2023 8:57 PM
To:
Manufacturers cannot side-step liability by claiming ignorance. The
manufacture is solely responsible for any product they place on the market,
with or without the correct power cord.
From: Douglas Powell
Sent: Friday, August 11, 2023 7:53 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re:
How would the customs folks in those countries check appliance line cords ?
Do they open boxes, pull contents, and inspect?
If the USA plug is not rated for higher voltage, does it really present a
hazard ? (compliance vs safety) The USA/Canadian plugs have a LOTS of
creepage distance
Cord-connected equipment?
From: Elliott Martinson
Sent: Thursday, August 10, 2023 12:27 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Necessary Lab accreditations, class 2 permissible change
If it were to become a leakage current issue, Id wonder whether the
parasitic inductance
UL1973 and UL1642 do a pretty through job of addressing functional safety of
batteries and safety of the individual cells. Perhaps some LiON batteries are
finding their way into the USA market without 3rd party certification. How to
prevent uncertified or unlisted products from reaching the
Doug, a quick search through NFPA70 (USA national electrical code) says in
article 645 Information Technology Equipment:
645.16 Marking. Each unit of an information technology system supplied by a
branch circuit shall be provided with a
manufacturer's nameplate, which shall also include the
to, as in shock versus electrocution protection.
Is 6mA enough for strong muscle reaction or a startle reaction sufficient to
cause someone to loose balance for instance?
Still, some protection better than none at all.
Ralph McDiarmid
Product Compliance Specialist
Solar Business
Schneider
Agreed, and current carry-carrying of PE and bonding of internal parts must
meet stringent UL/CSA requirements. (not mA!) It seems to me that 30mA is
close to lethal, and the GFCI outlets Listed over here are 6mA trip. (still a
painful shock)
Ralph McDiarmid
Product Compliance Specialist
put connector with just such a probe,
modified to keep probe parasitic inductance to a minimum.
At least that’s what I think is going on with Doug’s demonstration.
Ralph McDiarmid
Solar Business
Schneider Electric
From: Doug Smith [mailto:d...@emcesd.com]
Sent: Friday, January 26, 2018 2:50 PM
To:
That’s what we do here, when needed.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: Pat Lawler [mailto:plawl...@gmail.com]
Sent: Thursday, December 21, 2017 6:18 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] CI Software Flicker/Harmonics
Hi
A co-op computer science student on a work term would probably wrestle that to
the ground in short order.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Wednesday, December 20, 2017 1:26 PM
To: EMC-PSTC
oes not need 8G of ram
nor does it need Windows 10, we're happy with it thanks and it only control
this or that instrument and there is no network connectivity . . . so kindly
buzz off" (or words to that effect) ;^))
Ralph McDiarmid
Product Compliance
Engineering
Solar Busines
I agree it is a serious omission, but perhaps the technique is so rarely used
the question doesn't arise?
Thermocouples do a pretty good job IF they are carefully affixed and IF a few
are placed, at various locations on the winding.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
is
limited to 85C rise (in 25C ambient) using thermocouple method.
The discrepancy accounts for hotspots inside the coil which may be much warmer
than the coil surface measurement. See table 3 in that standard and read all
its notes.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Sure, but fiber optics are special purpose, dedicate circuits. Isn't this
fella talking about using existing luminaire in the home for data transmission?
Maybe I don't know enough about his concept.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From
I haven't studied it, but seems to me that one would need to modulate the light
very quickly to get any sort of usable BAUD rate, unless you settle for
transmission of text only. (like the good old Bell 202 modems over voice band
land lines)
Ralph McDiarmid
Product Compliance
Engineering
for capacitive
elements)
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: Peter Tarver [mailto:ptar...@enphaseenergy.com]
Sent: Friday, December 08, 2017 5:23 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Pilot rating
Hi, Jon.
Switching
(dissipate) the energy
stored in the coil during turn-off release. Could save your circuit cost of
two zeners.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: Adam Dixon [mailto:lanterna.viri...@gmail.com]
Sent: Thursday, December 07, 2017 2:42 PM
To
Series-pass regulator with a simple bridge rectifier is not zero emission, but
negligible compared to a well-filtered switch-mode PSU.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: John Woodgate [mailto:j...@woodjohn.uk]
Sent: Wednesday, November 22
well.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
-Original Message-
From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Wednesday, November 22, 2017 8:28 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Use of LED Spots in EMC Chambers
My assumption as well
Perhaps, but keep in mind that the impedance specified by 60725 is a maximum
value that 90% of household service would not exceed. It might be 1/2 that
value on average.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
be
twice that value or higher for some customers
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
-Original Message-
From: Brian O'Connell [mailto:oconne...@tamuracorp.com]
Sent: Monday, November 20, 2017 10:26 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re
0.5A without further increase in current.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
-Original Message-
From: Joe Randolph [mailto:j...@randolph-telecom.com]
Sent: Monday, November 13, 2017 7:56 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES
I've see MOVS flame after being hit repeatedly with 6kV combination wave surges
too quickly (30s apart), during type testing to ANSI C62.45
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
-Original Message-
From: Joe Randolph [mailto:j...@randolph
Indeed, why not merely add a Peak limit or perhaps better, an Average limit?
Doing that would avoid an effort to clarify the issue with words. Avg & QP
limits have served well in CISPR11 and in CISPR22 for a long time.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schne
, since the principles of electric circuits can be
taught just as effectively using magnitude 1 energy sources.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
-Original Message-
From: Richard Nute [mailto:ri...@ieee.org]
Sent: Thursday, November 09
ccredited
institute, not just on-the-job experience. I have fixed a few TVs in my time,
but I wouldn't say I was qualified; skilled maybe.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
-Original Message-
From: Joe Randolph [mailto:j...@randolp
some considerable
resistance (no pun intended)
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: Joe Randolph [mailto:j...@randolph-telecom.com]
Sent: Tuesday, October 31, 2017 9:43 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Regulatory requirements
I think Charlie’s final bullet point is key. The customs and surveillance
authorities are looking for references to the latest harmonized standards in a
DofC. The don’t understand or will not accept the concept of ‘presumption of
conformity’; they want to see the EN standards listed.
Ralph
I thought it was 15% duty cycle.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: James Pawson (U3C) [mailto:ja...@unit3compliance.co.uk]
Sent: Monday, October 16, 2017 7:31 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] IEC 61000-3-2 Confusion
Hi
plus 125 percent of the continuous load."
It's easy for our equipment where it is always supplied by a dedicated "branch
circuit" (often a dedicated transformer) and current is continuous by
definition. (> 3hrs)
Strictly speaking, it's a 125% rule, not an 80% rule
Ralph McDia
Since you're asking for an opinion and since IEC would allow it, I think it's
reasonable to allow it in N.Am too. There is no apparent hazard; the 15A OCPD
adequately protects both the connector and the cordage.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
That is an interesting technical point. Notice that EN61000-6-3 (generic
residential) calls out 61000-3-2, -3, -11 and -12, but EN61000-6-4
(industrial) does not.
Presumably, EN61000-6-4 makes full provision for the apparatus ?
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
I wonder if your customer's triac equipment falls under the EN61000-6-4 (EMC)
Emission standard for
industrial environments? I didn't see 61000-3-2 called out in that generic
standard.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: James Pawson (U3C
Sounds like an example of the 125% rule for continuous (>3hr) current. (20/16)
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org]
Sent: Wednesday, October 11, 2017 5:50 AM
To: EMC-P
, and short circuit PV currents need a 1.25 multiplier.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: Ted Eckert [mailto:07cf6ebeab9d-dmarc-requ...@ieee.org]
Sent: Tuesday, October 10, 2017 1:58 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES
The NEC (NFPA 70) talks about “continuous currents” and when to apply the
all-too-familiar 125% rule. Canadian Electric Code (CSA part I) has same
requirement. The IEC seems to have avoided it.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
D 604-422-2622
Maybe a padlock symbol, if there is no “standardized” symbol offered by ISO
Restricted Access locations are commonly locked, and only the privileged few
have the key
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: Doug Powell [mailto:doug...@gmail.com
I trust all the good background information in C62.41.1 doesn't get lost when
pull the standard in 2018. Hopefully it gets transferred (and perhaps revised)
to a new IEEE std.
I will hazard a guess that MSPD stands for Mains Surge Protection Device.
Ralph McDiarmid
Product Compliance
for those. The
ANSI standard seems a very good summary of what is a complex topic.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: Richard Nute [mailto:ri...@ieee.org]
Sent: Saturday, September 16, 2017 12:30 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re
Pardon me, the correct reference is ANSI C62.41.1 (finger trouble on keyboard)
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
-Original Message-
From: Ralph McDiarmid
Sent: Monday, September 18, 2017 8:55 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE
I invite you to also read the Preface in the NEC 2014 Handbook. It provides an
interesting history.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
-Original Message-
From: Richard Nute [mailto:ri...@ieee.org]
Sent: Friday, September 15, 2017 12:42
peculiar requirements we
find in the NEC.
Anyway, I've again drifted off topic and into a mini rant. Sorry about that.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: Scott Aldous [mailto:scottald...@google.com]
Sent: Friday, September 15, 2017 11:00 AM
this, but the rule goes way back in the
code. Anybody know where it came from? You won't find it in any part of IEC
60364-4-43. Apparently, the NEC 'code' was derived originally from the IEC.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: Pete Perkins
a justification. Someone
must have written one.
If UL Lists a circuit breaker at 15A, then there are no ‘conditions of
acceptability’ like those for a Recognized component, and so 15A should be just
fine for > 3hours, otherwise the marking is misleading at best.
Ralph McDiarmid
Product Complia
Gee, and I thought SDOs like UL and CSA were the only ones with issues. ;^))
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: John Woodgate [mailto:jmw1...@btinternet.com]
Sent: Monday, September 11, 2017 2:34 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re
in the lab
and in the field before agreeing on the LISN as a standard transducer for the
evaluation of conducted RF emission.
If there were something fundamentally wrong with the method of measurement, I
suspect it would have been uncovered long ago.
Ralph McDiarmid
Product Compliance
Engineering
the DUT. I think save to say
that most DUTs will have a least two power poles, a "line" and a "neutral for
connection to the a.c. mains.
I think some manufactures provide a graph or two plotting something (perhaps
insertion loss versus frequency) for that serial number.
I hope t
I agree that the AMN (LISN) is intended only to provide consistent (more or
less) results, not to represent a real-world impedance at RF. I don't know how
much that impedance changes from site to site; quite a lot I'll bet.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
ce further away from the ideal 50
ohms.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: Ken Javor [mailto:ken.ja...@emccompliance.com]
Sent: Monday, September 11, 2017 10:21 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] LISN Calibration Measurem
Hi Brian,
An open-circuit of 15kV pk and short-circuit peak of 7500A, tells me an
internal impedance of 2 ohms. If I recall correctly, 61000-4-5 specifies
source impedance, depending on L-L or L-G coupling (2 ohms or 12 ohms)
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Just curious to why delete the highest and lowest values before taking the
average?
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: John Woodgate [mailto:jmw1...@btinternet.com]
Sent: Thursday, August 10, 2017 5:00 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Yes, however, I haven't seen a slide rule in 40 years nor an analog meter in
20 years.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
-Original Message-
From: Richard Nute [mailto:ri...@ieee.org]
Sent: Tuesday, August 01, 2017 9:59 AM
To: Ralph
Those topics used to be taught in engineer school. That should not be
on-the-job learning.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: Brent DeWitt [mailto:bdew...@ix.netcom.com]
Sent: Monday, July 31, 2017 8:09 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
television receivers suffered similar susceptibility to impulsive
noise because the video carrier was amplitude-modulated and had a much wider
bandwidth compared to an AM receiver.
Ralph McDiarmid
Product Compliance
Engineering
Solar Business
Schneider Electric
From: John Woodgate [m
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