Re: [PSES] 61010-1 hazardous live classification

[Bansi Patel]

James:

 

I think it was Richard Nute, who has been instrumental is grounding and safe
equipment throughout his carrier.

He would love to hear from you.

He will be guest speaker for Virtual chapter of PSES (Product Safety
Engineering Society) of IEEE in coming months. 

Please send me an email and I can provide you with the details.

 

Best Regards and Be Safe

Bansi Patel

BRP Consultants

PSES BoG at large 2020-2023

PSES Vice President of Conferences 2020-2024

bansipate...@gmail.com <mailto:bansipate...@gmail.com> 

M:   909-260-9403

Please plan to attend Face-to-Face event: 

ISPCE  2024, (April 30-May 2, 2024); Chicago Area, Illinois, USA

https://2024.psessymposium.org <https://2024.psessymposium.org/> 

 

From: James Pawson (U3C)  
Sent: Wednesday, February 28, 2024 1:39 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] 61010-1 hazardous live classification

 

Hello all,

 

Thanks for all the responses and for some thoughts on the nuances. I'm
helping a customer with their risk assessment so being able to understand
the risks a little better is most useful.

 

Someone pointed out the relaxation in EN 62368-1 for pulse amplitudes based
on duty cycle which is also going to be useful.

 

Much appreciated as always.

 

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 <http://www.unit3compliance.co.uk/>  |
ja...@unit3compliance.co.uk <mailto: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
available/contactable between 1300h to 1730h Mon/Tue/Thurs/Fri.

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

 

 

 

 

From: James Pawson (U3C) mailto:ja...@unit3compliance.co.uk> > 
Sent: Monday, February 26, 2024 1:38 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto: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 you, it being Monday
after all.

 

1.  A piece of equipment with a power supply output for driving a lamp.
It has two modes, DC and pulsed.
2.  Both of the output voltage connections are on accessible terminals
(checked using finger probe)
3.  Classifying voltages as per EN 61010-1 clause 6.3.1 (limit values
for accessible parts, normal operating conditions)
4.  DC mode runs at 46Vdc maximum. This is less than 60Vdc so is not
Hazardous Live
5.  Pulse mode runs at 46Vdc pulsed (frequency up to 1kHz, duty cycle
can vary down to 0.01%) which is an AC waveform greater than 42.4V peak so
is Hazardous Live
6.  The output from the equipment is low impedance so is more than
capable of sourcing the required 0.7mA through the IEC 60990 body model.

 

Quick sketch attached to illustrate the concept. I even ran a SPICE
simulation to make sure I wasn't getting something wrong.

 

I would appreciate the sanity check!

 

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 <http://www.unit3compliance.co.uk/>  |
ja...@unit3compliance.co.uk <mailto: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
available/contactable between 1300h to 1730h Mon/Tue/Thurs/Fri.

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

 

 

 

 

  _  

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Re: [PSES] 61010-1 hazardous live classification

[James Pawson (U3C)]

Hello all,

 

Thanks for all the responses and for some thoughts on the nuances. I'm
helping a customer with their risk assessment so being able to understand
the risks a little better is most useful.

 

Someone pointed out the relaxation in EN 62368-1 for pulse amplitudes based
on duty cycle which is also going to be useful.

 

Much appreciated as always.

 

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 <http://www.unit3compliance.co.uk/>  |
ja...@unit3compliance.co.uk <mailto: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
available/contactable between 1300h to 1730h Mon/Tue/Thurs/Fri.

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

 

 

 

 

From: James Pawson (U3C)  
Sent: Monday, February 26, 2024 1:38 PM
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 you, it being Monday
after all.

 

1.  A piece of equipment with a power supply output for driving a lamp.
It has two modes, DC and pulsed.
2.  Both of the output voltage connections are on accessible terminals
(checked using finger probe)
3.  Classifying voltages as per EN 61010-1 clause 6.3.1 (limit values
for accessible parts, normal operating conditions)
4.  DC mode runs at 46Vdc maximum. This is less than 60Vdc so is not
Hazardous Live
5.  Pulse mode runs at 46Vdc pulsed (frequency up to 1kHz, duty cycle
can vary down to 0.01%) which is an AC waveform greater than 42.4V peak so
is Hazardous Live
6.  The output from the equipment is low impedance so is more than
capable of sourcing the required 0.7mA through the IEC 60990 body model.

 

Quick sketch attached to illustrate the concept. I even ran a SPICE
simulation to make sure I wasn't getting something wrong.

 

I would appreciate the sanity check!

 

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 <http://www.unit3compliance.co.uk/>  |
ja...@unit3compliance.co.uk <mailto: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
available/contactable between 1300h to 1730h Mon/Tue/Thurs/Fri.

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

 

 

 

 

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Re: [PSES] 61010-1 hazardous live classification

[Ralph McDiarmid]

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
Subject: [PSES] 61010-1 hazardous live classification

 

Hello all,

 

I hope this safety question is a fairly simple one for you, it being Monday
after all.

 

1.  A piece of equipment with a power supply output for driving a lamp.
It has two modes, DC and pulsed.
2.  Both of the output voltage connections are on accessible terminals
(checked using finger probe)
3.  Classifying voltages as per EN 61010-1 clause 6.3.1 (limit values
for accessible parts, normal operating conditions)
4.  DC mode runs at 46Vdc maximum. This is less than 60Vdc so is not
Hazardous Live
5.  Pulse mode runs at 46Vdc pulsed (frequency up to 1kHz, duty cycle
can vary down to 0.01%) which is an AC waveform greater than 42.4V peak so
is Hazardous Live
6.  The output from the equipment is low impedance so is more than
capable of sourcing the required 0.7mA through the IEC 60990 body model.

 

Quick sketch attached to illustrate the concept. I even ran a SPICE
simulation to make sure I wasn't getting something wrong.

 

I would appreciate the sanity check!

 

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 <http://www.unit3compliance.co.uk/>  |
ja...@unit3compliance.co.uk <mailto: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
available/contactable between 1300h to 1730h Mon/Tue/Thurs/Fri.

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

 

 

 

 

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Re: [PSES] 61010-1 hazardous live classification

[Ralph McDiarmid]

Thanks Scott.  I will read that preview.

 

From: Scott Aldous  
Sent: Monday, February 26, 2024 3:21 PM
To: rmm.priv...@gmail.com
Cc: EMC-PSTC@listserv.ieee.org
Subject: Re: [PSES] 61010-1 hazardous live classification

 

Use of shock hazard limits in terms of voltage in product safety 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:rmm.priv...@gmail.com> > wrote:

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)

 

I went back to first principles, did the integration of a d.c pulsed waveform 
and then again for an a.c. waveform with same amplitude, same duty ratio.  I 
found a much higher effective value (RMS) with the a.c. waveform having sample 
amplitude and pulse duty ratio.  For example, Root2 higher for 50% duty cycle 
and Root10 higher for 10% duty cycle.

 

Now, the NRTL won’t be interested in any of that, but you need to weigh the 
intent of the standard versus any other risk analysis might do above and beyond 
the “letter of the law” before deciding on whether those terminals are in fact 
shock hazardous.  It’s your product, your call, your corporate reputation, so 
whatever the decision, it needs to be justified with due diligence.

 

I would say your power supply output as described satisfies the criteria of 
“limit values for accessible parts” as defined in IEC61010 3rd edition.  (33 
Vrms, 33xroot2 Vpeak, and 70 Vdc )   A project holder at an NRTL might disagree.

 

Ralph

 

From: Richard Nute mailto:ri...@ieee.org> > 
Sent: Monday, February 26, 2024 12:08 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> 
Subject: Re: [PSES] 61010-1 hazardous live classification

 

 

Hi James:

 

In the pulse mode, 46 volts peak exceeds the 42.4 volts peak limit.  In 
accordance with the 61010 standard, the voltage cannot be accessible in the 
pulse mode.

 

However, the pulse mode is dc (the current does not reverse).  The RMS of such 
a pulse is 46 times the square root of the duty cycle.  The shorter the duty 
cycle, the less human sensation of the pulse.  Chances are that the pulse is 
not detectable by a human finger any more than 60 volts DC.  But the standard 
does not allow such a determination.  

 

You are stuck.

 

Best regards,

Richard Nute

Bend, Oregon, USA

 

 

From: James Pawson (U3C) mailto:ja...@unit3compliance.co.uk> > 
Sent: Monday, February 26, 2024 5:38 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto: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 you, it being Monday 
after all…

 

1.  A piece of equipment with a power supply output for driving a lamp. It 
has two modes, DC and pulsed.
2.  Both of the output voltage connections are on accessible terminals 
(checked using finger probe)
3.  Classifying voltages as per EN 61010-1 clause 6.3.1 (limit values for 
accessible parts, normal operating conditions)
4.  DC mode runs at 46Vdc maximum. This is less than 60Vdc so is not 
Hazardous Live
5.  Pulse mode runs at 46Vdc pulsed (frequency up to 1kHz, duty cycle can 
vary down to 0.01%) which is an AC waveform greater than 42.4V peak so is 
Hazardous Live
6.  The output from the equipment is low impedance so is more than capable 
of sourcing the required 0.7mA through the IEC 60990 body model.

 

Quick sketch attached to illustrate the concept. I even ran a SPICE simulation 
to make sure I wasn’t getting something wrong.

 

I would appreciate the sanity check!

 

All the best

James

 


  _  


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For policy questions, 

Re: [PSES] 61010-1 hazardous live classification

[Scott Aldous]

Use of shock hazard limits in terms of voltage in product safety 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 
wrote:

> 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)
>
>
>
> I went back to first principles, did the integration of a d.c pulsed
> waveform and then again for an a.c. waveform with same amplitude, same duty
> ratio.  I found a much higher effective value (RMS) with the a.c. waveform
> having sample amplitude and pulse duty ratio.  For example, Root2 higher
> for 50% duty cycle and Root10 higher for 10% duty cycle.
>
>
>
> Now, the NRTL won’t be interested in any of that, but you need to weigh
> the intent of the standard versus any other risk analysis might do above
> and beyond the “letter of the law” before deciding on whether those
> terminals are in fact shock hazardous.  It’s your product, your call, your
> corporate reputation, so whatever the decision, it needs to be justified
> with due diligence.
>
>
>
> I would say your power supply output as described satisfies the criteria
> of “limit values for accessible parts” as defined in IEC61010 3rd
> edition.  (33 Vrms, 33xroot2 Vpeak, and 70 Vdc )   A project holder at an
> NRTL might disagree.
>
>
>
> Ralph
>
>
>
> *From:* Richard Nute 
> *Sent:* Monday, February 26, 2024 12:08 PM
> *To:* EMC-PSTC@LISTSERV.IEEE.ORG
> *Subject:* Re: [PSES] 61010-1 hazardous live classification
>
>
>
>
>
> Hi James:
>
>
>
> In the pulse mode, 46 volts peak exceeds the 42.4 volts peak limit.  In
> accordance with the 61010 standard, the voltage cannot be accessible in the
> pulse mode.
>
>
>
> However, the pulse mode is dc (the current does not reverse).  The RMS of
> such a pulse is 46 times the square root of the duty cycle.  The shorter
> the duty cycle, the less human sensation of the pulse.  Chances are that
> the pulse is not detectable by a human finger any more than 60 volts DC.
> But the standard does not allow such a determination.
>
>
>
> You are stuck.
>
>
>
> Best regards,
>
> Richard Nute
>
> Bend, Oregon, USA
>
>
>
>
>
> *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 you, it being
> Monday after all…
>
>
>
>1. A piece of equipment with a power supply output for driving a lamp.
>It has two modes, DC and pulsed.
>2. Both of the output voltage connections are on accessible terminals
>(checked using finger probe)
>3. Classifying voltages as per EN 61010-1 clause 6.3.1 (limit values
>for accessible parts, normal operating conditions)
>4. DC mode runs at 46Vdc maximum. This is less than 60Vdc so is not
>Hazardous Live
>5. Pulse mode runs at 46Vdc pulsed (frequency up to 1kHz, duty cycle
>can vary down to 0.01%) which is an AC waveform greater than 42.4V peak so
>is Hazardous Live
>6. The output from the equipment is low impedance so is more than
>capable of sourcing the required 0.7mA through the IEC 60990 body model.
>
>
>
> Quick sketch attached to illustrate the concept. I even ran a SPICE
> simulation to make sure I wasn’t getting something wrong.
>
>
>
> I would appreciate the sanity check!
>
>
>
> All the best
>
> James
>
>
> --
>
> 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
> EMC-PSTC@LISTSERV.IEEE.ORG
>
> All emc-pstc postings are archived and searchable on the web at:
> https://www.mail-archive.com/emc-pstc@listserv.ieee.org/
> <https://www.mail-archive.com/emc-pstc@listserv.ieee.org/%20>
>
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>
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> Rick Linford at: linf...@ieee.org
>

Re: [PSES] 61010-1 hazardous live classification

[Ralph McDiarmid]

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)

 

I went back to first principles, did the integration of a d.c pulsed
waveform and then again for an a.c. waveform with same amplitude, same duty
ratio.  I found a much higher effective value (RMS) with the a.c. waveform
having sample amplitude and pulse duty ratio.  For example, Root2 higher for
50% duty cycle and Root10 higher for 10% duty cycle.

 

Now, the NRTL won't be interested in any of that, but you need to weigh the
intent of the standard versus any other risk analysis might do above and
beyond the "letter of the law" before deciding on whether those terminals
are in fact shock hazardous.  It's your product, your call, your corporate
reputation, so whatever the decision, it needs to be justified with due
diligence.

 

I would say your power supply output as described satisfies the criteria of
"limit values for accessible parts" as defined in IEC61010 3rd edition.  (33
Vrms, 33xroot2 Vpeak, and 70 Vdc )   A project holder at an NRTL might
disagree.

 

Ralph

 

From: Richard Nute  
Sent: Monday, February 26, 2024 12:08 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] 61010-1 hazardous live classification

 

 

Hi James:

 

In the pulse mode, 46 volts peak exceeds the 42.4 volts peak limit.  In
accordance with the 61010 standard, the voltage cannot be accessible in the
pulse mode.

 

However, the pulse mode is dc (the current does not reverse).  The RMS of
such a pulse is 46 times the square root of the duty cycle.  The shorter the
duty cycle, the less human sensation of the pulse.  Chances are that the
pulse is not detectable by a human finger any more than 60 volts DC.  But
the standard does not allow such a determination.  

 

You are stuck.

 

Best regards,

Richard Nute

Bend, Oregon, USA

 

 

From: James Pawson (U3C) mailto:ja...@unit3compliance.co.uk> > 
Sent: Monday, February 26, 2024 5:38 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto: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 you, it being Monday
after all.

 

1.  A piece of equipment with a power supply output for driving a lamp.
It has two modes, DC and pulsed.
2.  Both of the output voltage connections are on accessible terminals
(checked using finger probe)
3.  Classifying voltages as per EN 61010-1 clause 6.3.1 (limit values
for accessible parts, normal operating conditions)
4.  DC mode runs at 46Vdc maximum. This is less than 60Vdc so is not
Hazardous Live
5.  Pulse mode runs at 46Vdc pulsed (frequency up to 1kHz, duty cycle
can vary down to 0.01%) which is an AC waveform greater than 42.4V peak so
is Hazardous Live
6.  The output from the equipment is low impedance so is more than
capable of sourcing the required 0.7mA through the IEC 60990 body model.

 

Quick sketch attached to illustrate the concept. I even ran a SPICE
simulation to make sure I wasn't getting something wrong.

 

I would appreciate the sanity check!

 

All the best

James

 

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Re: [PSES] 61010-1 hazardous live classification

[Richard Nute]

 

Hi James:

 

In the pulse mode, 46 volts peak exceeds the 42.4 volts peak limit.  In
accordance with the 61010 standard, the voltage cannot be accessible in the
pulse mode.

 

However, the pulse mode is dc (the current does not reverse).  The RMS of
such a pulse is 46 times the square root of the duty cycle.  The shorter the
duty cycle, the less human sensation of the pulse.  Chances are that the
pulse is not detectable by a human finger any more than 60 volts DC.  But
the standard does not allow such a determination.  

 

You are stuck.

 

Best regards,

Richard Nute

Bend, Oregon, USA

 

 

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 you, it being Monday
after all.

 

1.  A piece of equipment with a power supply output for driving a lamp.
It has two modes, DC and pulsed.
2.  Both of the output voltage connections are on accessible terminals
(checked using finger probe)
3.  Classifying voltages as per EN 61010-1 clause 6.3.1 (limit values
for accessible parts, normal operating conditions)
4.  DC mode runs at 46Vdc maximum. This is less than 60Vdc so is not
Hazardous Live
5.  Pulse mode runs at 46Vdc pulsed (frequency up to 1kHz, duty cycle
can vary down to 0.01%) which is an AC waveform greater than 42.4V peak so
is Hazardous Live
6.  The output from the equipment is low impedance so is more than
capable of sourcing the required 0.7mA through the IEC 60990 body model.

 

Quick sketch attached to illustrate the concept. I even ran a SPICE
simulation to make sure I wasn't getting something wrong.

 

I would appreciate the sanity check!

 

All the best

James

 


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Re: [PSES] 61010-1 hazardous live classification

[Ralph McDiarmid]

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 you, it being Monday
after all.

 

1.  A piece of equipment with a power supply output for driving a lamp.
It has two modes, DC and pulsed.
2.  Both of the output voltage connections are on accessible terminals
(checked using finger probe)
3.  Classifying voltages as per EN 61010-1 clause 6.3.1 (limit values
for accessible parts, normal operating conditions)
4.  DC mode runs at 46Vdc maximum. This is less than 60Vdc so is not
Hazardous Live
5.  Pulse mode runs at 46Vdc pulsed (frequency up to 1kHz, duty cycle
can vary down to 0.01%) which is an AC waveform greater than 42.4V peak so
is Hazardous Live
6.  The output from the equipment is low impedance so is more than
capable of sourcing the required 0.7mA through the IEC 60990 body model.

 

Quick sketch attached to illustrate the concept. I even ran a SPICE
simulation to make sure I wasn't getting something wrong.

 

I would appreciate the sanity check!

 

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 <http://www.unit3compliance.co.uk/>  |
ja...@unit3compliance.co.uk <mailto: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
available/contactable between 1300h to 1730h Mon/Tue/Thurs/Fri.

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

 

 

 

 

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Re: [PSES] 61010-1 hazardous live classification

[John Woodgate]

I think you analysis is correct.

On 2024-02-26 13:38, James Pawson (U3C) wrote:


Hello all,

I hope this safety question is a fairly simple one for you, it being 
Monday after all…


 1. A piece of equipment with a power supply output for driving a
lamp. It has two modes, DC and pulsed.
 2. Both of the output voltage connections are on accessible terminals
(checked using finger probe)
 3. Classifying voltages as per EN 61010-1 clause 6.3.1 (limit values
for accessible parts, normal operating conditions)
 4. DC mode runs at 46Vdc maximum. This is less than 60Vdc so is not
Hazardous Live
 5. Pulse mode runs at 46Vdc pulsed (frequency up to 1kHz, duty cycle
can vary down to 0.01%) which is an AC waveform greater than 42.4V
peak so is Hazardous Live
 6. The output from the equipment is low impedance so is more than
capable of sourcing the required 0.7mA through the IEC 60990 body
model.

Quick sketch attached to illustrate the concept. I even ran a SPICE 
simulation to make sure I wasn’t getting something wrong.


I would appreciate the sanity check!

**

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 
available/contactable between 1300h to 1730h Mon/Tue/Thurs/Fri./


/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./




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--
Signature OOO - Own Opinions Only
Best wishes
John Woodgate, Rayleigh, Essex UK
Keep trying

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