Re: [PSES] Clearances >30 kHz

[Boštjan Glavič]

Dear Ryan,

Table 10 - input is your temporary overvoltage. Normally 2000Vpk for mains 
voltages up to 250Vac
Table 11 - input is your working voltage
Table 14 - input is your transient voltage - defined by OVC (for OVC II 
2500Vpk).
So table 11 brings you very low value and normally table 10 and 15 are 
dominating.

I hope this helps.

Best regards,
Boštjan



From: Ryan Jazz 
Sent: Wednesday, July 26, 2023 12:39 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] Clearances >30 kHz

CAUTION: This email originated from outside of our organisation. Do not click 
links or open attachments unless you recognise the sender and know the content 
is safe.

Dear Members,
Hope you can help me understand the requirement for the clearance needed 
between the bottom PCB of power supply to metal chassis.
Looking up UL 62368-1 Third Edition, and using the 'Voltage up to an including 
peak' of 2000 V for overvoltage category II Table 10 for <30 kHz.
I see the clearance is 1,27 mm.
Going over to Table 11 >30 kHz this clearance value jumps to 13,2 mm.
Am I doing this correctly? Or should I be using the 'working voltage' of the 
power supply, Primary to Earthed Dead Metal 392 Vpk, Primary to Secondary 520 
Vpk.
100-240 Vac, 100 W, 90 kHz switching frequency, AC power supply with a 2x3 inch 
footprint.
End product is, overvoltage category II, pollution degree 2, material group III.
Indoor audio music processor, Class 1.
All guidance would be appreciated.
If this 13,2 mm value is indeed correct, I may need to use an insulator under 
the power supply.
Any recommendations for a UL rated insulator type?
Thank you,
Ryan Jazz
Ryan Jayasinghe
Regulatory Compliance Engineer
rjayasin...@line6.com

"After silence, that which best expresses the inexpressible, is music" - Aldous 
Huxley

LINE6
26580 Agoura Road
Calabasas CA 91302
818.575.3711
line6.com
ampeg.com



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Re: [PSES] Woodgate's reply on residential Immunity field strength

[Ken Javor]

I don’t see 100 V/m. Assuming an omni pattern, 0.5 W peak power and using, 

 

E = √(30•ERP) / r

 

the phone would need to be within a few centimeters of the observation point, 
and in that close the distance scaling assumption in that equation breaks down.

 

-- 

Ken Javor

(256) 650-5261

 

From: "doug emcesd.com" 
Reply-To: "doug emcesd.com" 
Date: Tuesday, July 25, 2023 at 6:53 PM
To: 
Subject: Re: [PSES] Woodgate's reply on residential Immunity field strength

 

Hi All,

 

My observation is that a cell phone at max power, close to the product, 
generates voltages and currents in the product that are on the order of what a 
100 V/m far field would induce!

 

I have seen many manifestations of this including making a product permanently 
non-functional. Interestingly enough, the design feature within that product 
that caused the issue was ground fill on a circuit board that was resonant in 
the upper cell phone band. Pretty easy to find with signal injection into the 
structure.

 

These kind of problems are easily found using a coaxial dipole. Here are a few 
links:

 

https://emcesd.com/tt2006/tt020106.htm

 

https://emcesd.com/tt2010/tt080410.htm

 

As with ESD, using the standards based test setup for troubleshooting these 
kind of problems is very inefficient. Once a problem occurs, I build a custom 
way of injecting signals, like the above, and find the problem very quickly. In 
this case, one just needs a signal source of appropriate power and the coaxial 
dipole.

 

An interesting bit of my history. These days we think 10 V/m is dangerous. But 
when I was 15, I played for hours at a time with a device I made that generated 
a continuous signal at 300 kHz of 10,000-20,000 V/m and I am still here! I was 
developing 600 Watts of power from a pair of 811A power triodes oscillating at 
300 kHz to feed the resonant Tesla coil structure I built. The effects were 
pretty amazing, lighting up fluorescent tubes 4-6 feet away to full brilliance 
with no wires and even incandescent bulbs would light in the vicinity, held in 
my hand! Pieces of metal nearby got hot from induction heating.

 

I did lots of crazy technical things when I was 12-18 years of age. By the way, 
those 811A tubes above (the “A” versions had cooling fins on the plates) were 
powered from a 3B28 xenon gas rectifier tube and had 1500 V and at more than 
half an Ampere available on the plate caps. Enough to kill one rather quickly, 
but I knew what I was doing back then and survived to write this.

 

Doug

From: Charlie Blackham  
Sent: Tuesday, July 25, 2023 0:06
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Woodgate's reply on residential Immunity field strength

 

The residential level of 3m V/m was in IEC 1000-4-3 predates portable phones, 
WiFi, Bluetooth and all the other mobile and portable transmitters widely in 
use today.

 

The 20+ V/m field strengths in these standards are what is obtained from a 
cellular phone at maximum power, or WiFi device, at approximately 0.3 m / 1 ft.

 

Now, on live networks the 99% percentile transmit power of a cell phone is 
around 1% of maximum power, but that’s not considered in safety standards such 
as SAR testing

 

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: Brian Gregory  
Sent: Monday, July 24, 2023 10:49 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Woodgate's reply on residential Immunity field strength

 

 

The reference for 20 V/m to EV chargers comes from UL 2231-2.  This is not a 
medical standard, but Annex A does call out the medical standard 60601-1-2 as a 
reference, as well as CENELEC 50204.  We can't figure out why;  cell phones 
produce less than half that, and our WiFi transmitter is probably 
representative, and is rated well under 1 W.  I could see a higher immunity 
standard as needed for commercial environments, say in a bank of 4-5 chargers.

 

Following along in 61000-4-3, we agree with John that residential applications 
are clearly best matched to the definition for Class 2 environment, and the 
table in Clause 5 says the limits for Class 2 equipment is 3 V/m.  20 V/m does 
not show up in Clause 5 of 61000-4-3 for any class.  

 

So, I've should to reach out to a UL standards group and find out if this is 
really necessary for residential applications.   Our local lab can't do more 
than 10, and an overseas affiliated lab is similarly limited.  I'd like to know 
were this requirement comes from.   This is more a question for EV Charging 
safety than a mainstream EMC question. 

 

As a backup, I could request a comment to Ken's point is if they define the 
peak of the modulation as 20 V/m.  I don't know where these are defined.

 

Thanks for all the detailed replies!

 

Colorado Brian 
720-450-4933



-- Original Message --
From: John Woodgate 
To: Brian Gregory 

Re: [PSES] Woodgate's reply on residential Immunity field strength

[doug emcesd.com]

Hi All,

My observation is that a cell phone at max power, close to the product, 
generates voltages and currents in the product that are on the order of what a 
100 V/m far field would induce!

I have seen many manifestations of this including making a product permanently 
non-functional. Interestingly enough, the design feature within that product 
that caused the issue was ground fill on a circuit board that was resonant in 
the upper cell phone band. Pretty easy to find with signal injection into the 
structure.

These kind of problems are easily found using a coaxial dipole. Here are a few 
links:

https://emcesd.com/tt2006/tt020106.htm

https://emcesd.com/tt2010/tt080410.htm

As with ESD, using the standards based test setup for troubleshooting these 
kind of problems is very inefficient. Once a problem occurs, I build a custom 
way of injecting signals, like the above, and find the problem very quickly. In 
this case, one just needs a signal source of appropriate power and the coaxial 
dipole.

An interesting bit of my history. These days we think 10 V/m is dangerous. But 
when I was 15, I played for hours at a time with a device I made that generated 
a continuous signal at 300 kHz of 10,000-20,000 V/m and I am still here! I was 
developing 600 Watts of power from a pair of 811A power triodes oscillating at 
300 kHz to feed the resonant Tesla coil structure I built. The effects were 
pretty amazing, lighting up fluorescent tubes 4-6 feet away to full brilliance 
with no wires and even incandescent bulbs would light in the vicinity, held in 
my hand! Pieces of metal nearby got hot from induction heating.

I did lots of crazy technical things when I was 12-18 years of age. By the way, 
those 811A tubes above (the "A" versions had cooling fins on the plates) were 
powered from a 3B28 xenon gas rectifier tube and had 1500 V and at more than 
half an Ampere available on the plate caps. Enough to kill one rather quickly, 
but I knew what I was doing back then and survived to write this.

Doug
[https://lh4.googleusercontent.com/_HuR3Ky2TF_XhFHyxnYRmiq7nHQldnMsPNYFaLG6kb5T4y8MeCe-BDC_BscJtSFgszSSjssihHS-pjM3-jwNP8S0CwE-gN8fsRsPkojiAlmpBwb20vIVizS-siCUywW_jqrefbVr]
From: Charlie Blackham 
Sent: Tuesday, July 25, 2023 0:06
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Woodgate's reply on residential Immunity field strength

The residential level of 3m V/m was in IEC 1000-4-3 predates portable phones, 
WiFi, Bluetooth and all the other mobile and portable transmitters widely in 
use today.

The 20+ V/m field strengths in these standards are what is obtained from a 
cellular phone at maximum power, or WiFi device, at approximately 0.3 m / 1 ft.

Now, on live networks the 99% percentile transmit power of a cell phone is 
around 1% of maximum power, but that's not considered in safety standards such 
as SAR testing

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: Brian Gregory 
mailto:brian_greg...@netzero.net>>
Sent: Monday, July 24, 2023 10:49 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Woodgate's reply on residential Immunity field strength


The reference for 20 V/m to EV chargers comes from UL 2231-2.  This is not a 
medical standard, but Annex A does call out the medical standard 60601-1-2 as a 
reference, as well as CENELEC 50204.  We can't figure out why;  cell phones 
produce less than half that, and our WiFi transmitter is probably 
representative, and is rated well under 1 W.  I could see a higher immunity 
standard as needed for commercial environments, say in a bank of 4-5 chargers.

Following along in 61000-4-3, we agree with John that residential applications 
are clearly best matched to the definition for Class 2 environment, and the 
table in Clause 5 says the limits for Class 2 equipment is 3 V/m.  20 V/m does 
not show up in Clause 5 of 61000-4-3 for any class.

So, I've should to reach out to a UL standards group and find out if this is 
really necessary for residential applications.   Our local lab can't do more 
than 10, and an overseas affiliated lab is similarly limited.  I'd like to know 
were this requirement comes from.   This is more a question for EV Charging 
safety than a mainstream EMC question.

As a backup, I could request a comment to Ken's point is if they define the 
peak of the modulation as 20 V/m.  I don't know where these are defined.

Thanks for all the detailed replies!

Colorado Brian
720-450-4933


-- Original Message --
From: John Woodgate mailto:j...@woodjohn.uk>>
To: Brian Gregory mailto:brian_greg...@netzero.net>>

Re: [PSES] Clearances >30 kHz

[Scott Aldous]

Hi Ryan,

Clarification at the end of 5.4.2.2 (before the tables) indicates that
which table you use is dependent on the frequency of the associated
circuit. The implication is that you could have some circuits use Table 10
and some circuits use Table 11. It seems appropriate to use Table 11 for
the power supply working voltage. The key question here is whether
temporary overvoltages associated with AC mains circuits have a frequency >
30 kHz or not and so also should use Table 11, or if Table 10 should be
used.

FWIW, here

is a paper from UL from 2010 (so before IEC 62368-1 3rd Edition was
published) that has an example based on the IEC 60664 series standards. You
will notice that the example calculates clearances to withstand transient
overvoltages separately from the clearances to withstand periodic
voltages, taking the highest of the two as the final requirement. Though it
doesn't address temporary overvoltages specifically, the example is
interesting.

On Tue, Jul 25, 2023 at 3:39 PM Ryan Jazz 
wrote:

> Dear Members,
>
> Hope you can help me understand the requirement for the clearance needed
> between the bottom PCB of power supply to metal chassis.
>
> Looking up UL 62368-1 Third Edition, and using the ‘Voltage up to an
> including peak’ of *2000 V* for overvoltage category II Table 10 for *<30
> kHz*.
>
> I see the clearance is 1,27 mm.
>
> Going over to Table 11 *>30* kHz this clearance value jumps to 13,2 mm.
>
> Am I doing this correctly? Or should I be using the ‘working voltage’ of
> the power supply, Primary to Earthed Dead Metal 392 Vpk, Primary to
> Secondary 520 Vpk.
>
> 100-240 Vac, 100 W, *90 kHz* switching frequency, AC power supply with a
> 2x3 inch footprint.
>
> End product is, overvoltage category II, pollution degree 2, material
> group III.
>
> Indoor audio music processor, Class 1.
>
> All guidance would be appreciated.
>
> If this 13,2 mm value is indeed correct, I may need to use an insulator
> under the power supply.
>
> Any recommendations for a UL rated insulator type?
>
> Thank you,
>
> Ryan Jazz
>
> Ryan Jayasinghe
>
> Regulatory Compliance Engineer
>
> rjayasin...@line6.com
>
>
>
> "After silence, that which best expresses the inexpressible, is music" -
> Aldous Huxley
>
>
>
> LINE6
>
> 26580 Agoura Road
>
> Calabasas CA 91302
>
> 818.575.3711 <(818)%20575-3711>
>
> line6.com
>
> ampeg.com
>
>
> --
>
> 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:
> https://www.mail-archive.com/emc-pstc@listserv.ieee.org/
>
> Website: https://ewh.ieee.org/soc/pses/
> Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to
> unsubscribe) 
> List rules: https://ewh.ieee.org/soc/pses/listrules.html
>
> For help, send mail to the list administrators:
> Mike Sherman at: msherma...@comcast.net
> Rick Linford at: linf...@ieee.org
>
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> Jim Bacher at: j.bac...@ieee.org
> --
>
> To unsubscribe from the EMC-PSTC list, click the following link:
> https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC=1
>


-- 
Scott Aldous | Regulatory Compliance Manager | scottald...@google.com |
 650-253-1994

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Re: [PSES] Clearances >30 kHz

[John Woodgate]

Remarkable difference between 29.9 kHz and 30.1 kHz!

On 2023-07-25 23:39, Ryan Jazz wrote:


Dear Members,

Hope you can help me understand the requirement for the clearance 
needed between the bottom PCB of power supply to metal chassis.


Looking up UL 62368-1 Third Edition, and using the ‘Voltage up to an 
including peak’ of _2000 V_ for overvoltage category II Table 10 for 
_<30 kHz_.


I see the clearance is 1,27 mm.

Going over to Table 11 _>30_ kHz this clearance value jumps to 13,2 mm.

Am I doing this correctly? Or should I be using the ‘working voltage’ 
of the power supply, Primary to Earthed Dead Metal 392 Vpk, Primary to 
Secondary 520 Vpk.


100-240 Vac, 100 W, _90 kHz_ switching frequency, AC power supply with 
a 2x3 inch footprint.


End product is, overvoltage category II, pollution degree 2, material 
group III.


Indoor audio music processor, Class 1.

All guidance would be appreciated.

If this 13,2 mm value is indeed correct, I may need to use an 
insulator under the power supply.


Any recommendations for a UL rated insulator type?

Thank you,

Ryan Jazz

Ryan Jayasinghe

Regulatory Compliance Engineer

rjayasin...@line6.com

"After silence, that which best expresses the inexpressible, is music" 
- Aldous Huxley


LINE6

26580 Agoura Road

Calabasas CA 91302

818.575.3711

line6.com

ampeg.com



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[PSES] Clearances >30 kHz

[Ryan Jazz]

Dear Members,
Hope you can help me understand the requirement for the clearance needed 
between the bottom PCB of power supply to metal chassis.
Looking up UL 62368-1 Third Edition, and using the 'Voltage up to an including 
peak' of 2000 V for overvoltage category II Table 10 for <30 kHz.
I see the clearance is 1,27 mm.
Going over to Table 11 >30 kHz this clearance value jumps to 13,2 mm.
Am I doing this correctly? Or should I be using the 'working voltage' of the 
power supply, Primary to Earthed Dead Metal 392 Vpk, Primary to Secondary 520 
Vpk.
100-240 Vac, 100 W, 90 kHz switching frequency, AC power supply with a 2x3 inch 
footprint.
End product is, overvoltage category II, pollution degree 2, material group III.
Indoor audio music processor, Class 1.
All guidance would be appreciated.
If this 13,2 mm value is indeed correct, I may need to use an insulator under 
the power supply.
Any recommendations for a UL rated insulator type?
Thank you,
Ryan Jazz
Ryan Jayasinghe
Regulatory Compliance Engineer
rjayasin...@line6.com

"After silence, that which best expresses the inexpressible, is music" - Aldous 
Huxley

LINE6
26580 Agoura Road
Calabasas CA 91302
818.575.3711
line6.com
ampeg.com


-

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discussion list. To post a message to the list, send your e-mail to 


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Re: [PSES] Woodgate's reply on residential Immunity field strength

[Charlie Blackham]

The residential level of 3m V/m was in IEC 1000-4-3 predates portable phones, 
WiFi, Bluetooth and all the other mobile and portable transmitters widely in 
use today.

The 20+ V/m field strengths in these standards are what is obtained from a 
cellular phone at maximum power, or WiFi device, at approximately 0.3 m / 1 ft.

Now, on live networks the 99% percentile transmit power of a cell phone is 
around 1% of maximum power, but that's not considered in safety standards such 
as SAR testing

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: Brian Gregory 
Sent: Monday, July 24, 2023 10:49 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Woodgate's reply on residential Immunity field strength


The reference for 20 V/m to EV chargers comes from UL 2231-2.  This is not a 
medical standard, but Annex A does call out the medical standard 60601-1-2 as a 
reference, as well as CENELEC 50204.  We can't figure out why;  cell phones 
produce less than half that, and our WiFi transmitter is probably 
representative, and is rated well under 1 W.  I could see a higher immunity 
standard as needed for commercial environments, say in a bank of 4-5 chargers.

Following along in 61000-4-3, we agree with John that residential applications 
are clearly best matched to the definition for Class 2 environment, and the 
table in Clause 5 says the limits for Class 2 equipment is 3 V/m.  20 V/m does 
not show up in Clause 5 of 61000-4-3 for any class.

So, I've should to reach out to a UL standards group and find out if this is 
really necessary for residential applications.   Our local lab can't do more 
than 10, and an overseas affiliated lab is similarly limited.  I'd like to know 
were this requirement comes from.   This is more a question for EV Charging 
safety than a mainstream EMC question.

As a backup, I could request a comment to Ken's point is if they define the 
peak of the modulation as 20 V/m.  I don't know where these are defined.

Thanks for all the detailed replies!

Colorado Brian
720-450-4933


-- Original Message --
From: John Woodgate mailto:j...@woodjohn.uk>>
To: Brian Gregory mailto:brian_greg...@netzero.net>>
Subject: Re: [PSES] Immunity test field strength, residential setting
Date: Fri, 21 Jul 2023 18:05:59 +0100

61000-4-3 is a Basic Standard. It does not specify test levels but indicates 
possible test levels. You need to look in detail at Clause 5, but look at these 
words:

 Product committees shall select the appropriate test level for each frequency 
range needing to be tested as well as the frequency ranges.

The residential environment is usually designated Class 2 (see Annex E of the 
standard), which calls for 3 V/m.
==
Best wishes John Woodgate OOO-Own Opinions Only
www.woodjohn.uk
Rayleigh, Essex UK

I hear, and I forget. I see, and I remember. I do, and I understand. Xunzi (340 
- 245 BC)
On 2023-07-21 17:44, Brian Gregory wrote:
 Hello colleagues,

We are building EV Chargers for residential markets (not just US) and one of 
the safety applicable standards is UL 2231-2.  It calls out  IEC 61000-4-3 for 
immunity testing parameters, which states a requirement for a field strength of 
20V/m.  Our EMC expert says typically testing is "done at 3 Vrms, which is 
standard for most products in residential environments."   He can only test up 
to 10V, and we're hearing the same from an overseas lab to whom our 
manufacturer refers.

Does FCC Part B have guidelines for field strength we can cite?   Can some 
offer this "DC guy" (aka, 60 Hz) a quick definition of what the 20V/m 
represents?

I'm guessing 20 V/m is for higher density commercial applications, aka charging 
stations, so we probably need an exception for residential.

Thank you!

Colorado Brian
720-450-4933


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Re: [PSES] Woodgate's reply on residential Immunity field strength

[James Pawson (U3C)]

Hi Brian,

 

In IEC 61000-4-3 the level is defined as the unmodulated rms field strength.
The modulation (1kHz 80% AM) is applied symmetrically around that level.
>From memory this means that the peak is 5.1dB higher than the level.

 

The opposite is true in ISO 11452-2 for automotive where the level is the
maximum peak and the modulation (AM, same as above) is modulated down from
this peak.

 

All the best

James

 

James Pawson

Managing Director & EMC Problem Solver

 

Unit 3 Compliance Ltd

EMC : Environmental & Vibration : Electrical Safety : CE & UKCA :
Consultancy

 

  www.unit3compliance.co.uk |
 ja...@unit3compliance.co.uk 

+44(0)1274 911747  |  +44(0)7811 139957

2 Wellington Business Park, New Lane, Bradford, BD4 8AL

Registered in England and Wales # 10574298

 

Office hours:

Every morning my full attention is on consultancy, testing, and
troubleshooting activities for our customers' projects. I'm contactable
between 1300h to 1730h from Monday to Friday.

For inquiries, bookings, and testing updates please send us an email on
he...@unit3compliance.co.uk   or call
01274 911747. Our lead times for testing and consultancy are typically 4-5
weeks.

 

 

 

 

From: Brian Gregory  
Sent: Monday, July 24, 2023 10:49 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Woodgate's reply on residential Immunity field strength

 

 

The reference for 20 V/m to EV chargers comes from UL 2231-2.  This is not a
medical standard, but Annex A does call out the medical standard 60601-1-2
as a reference, as well as CENELEC 50204.  We can't figure out why;  cell
phones produce less than half that, and our WiFi transmitter is probably
representative, and is rated well under 1 W.  I could see a higher immunity
standard as needed for commercial environments, say in a bank of 4-5
chargers.

 

Following along in 61000-4-3, we agree with John that residential
applications are clearly best matched to the definition for Class 2
environment, and the table in Clause 5 says the limits for Class 2 equipment
is 3 V/m.  20 V/m does not show up in Clause 5 of 61000-4-3 for any class.  

 

So, I've should to reach out to a UL standards group and find out if this is
really necessary for residential applications.   Our local lab can't do more
than 10, and an overseas affiliated lab is similarly limited.  I'd like to
know were this requirement comes from.   This is more a question for EV
Charging safety than a mainstream EMC question. 

 

As a backup, I could request a comment to Ken's point is if they define the
peak of the modulation as 20 V/m.  I don't know where these are defined.

 

Thanks for all the detailed replies!

 

Colorado Brian 
720-450-4933



-- Original Message --
From: John Woodgate mailto:j...@woodjohn.uk> >
To: Brian Gregory mailto:brian_greg...@netzero.net> >
Subject: Re: [PSES] Immunity test field strength, residential setting
Date: Fri, 21 Jul 2023 18:05:59 +0100

61000-4-3 is a Basic Standard. It does not specify test levels but indicates
possible test levels. You need to look in detail at Clause 5, but look at
these words:

 Product committees shall select the appropriate test level for each
frequency range needing to be tested as well as the frequency ranges.

The residential environment is usually designated Class 2 (see Annex E of
the standard), which calls for 3 V/m.


==
Best wishes John Woodgate OOO-Own Opinions Only
www.woodjohn.uk  
Rayleigh, Essex UK

I hear, and I forget. I see, and I remember. I do, and I understand. Xunzi
(340 - 245 BC)

On 2023-07-21 17:44, Brian Gregory wrote:

 Hello colleagues, 

 

We are building EV Chargers for residential markets (not just US) and one of
the safety applicable standards is UL 2231-2.  It calls out  IEC 61000-4-3
for immunity testing parameters, which states a requirement for a field
strength of 20V/m.  Our EMC expert says typically testing is "done at 3
Vrms, which is standard for most products in residential environments."   He
can only test up to 10V, and we're hearing the same from an overseas lab to
whom our manufacturer refers.  

 

Does FCC Part B have guidelines for field strength we can cite?   Can some
offer this "DC guy" (aka, 60 Hz) a quick definition of what the 20V/m
represents?

 

I'm guessing 20 V/m is for higher density commercial applications, aka
charging stations, so we probably need an exception for residential.  

 

Thank you!

 

Colorado Brian 
720-450-4933

  _  

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