[PSES] SV: [PSES] Stripline - discontinuity in adjacent ground planes

[Amund Westin]

GND1-Signal = 200um 

Signal-GND2 = 220um

So there are slightly differences of the distances.

 

I have found two possible alternatives to change layout so the high speed
lines in Signal layer will have 100% GND return coupling all the way.

They should must have priority when interfering other signal /crtl. lines 

 

 

Regards Amund

 

 

Fra: James Pawson (U3C) 
Sendt: 18. mars 2020 09:51
Til: 'Amund Westin' ; EMC-PSTC@LISTSERV.IEEE.ORG
Emne: RE: [PSES] Stripline - discontinuity in adjacent ground planes

 

Hi Amund,

 

Are the distances from GND1-Signal the same as Signal-GND2 i.e. is the
Signal layer equidistant between the two GND layers? 

 

If so, broadly speaking, half of the field is going to be between GND1 and
signal and the other half will be between GND2 and signal. If the signal
layer is biased towards one or the other GND layer then you'll have
proportionally more field on one side than the other.

 

This isn't ideal but every layout is a compromise. Provided you can via
through from GND2 to GND1 at either side of the split this should keep the
return path controlled. It will still result in an impedance discontinuity
which could cause signal integrity issues. There's also the strong
possibility of crosstalk from the high speed lines onto the GND2 trace they
are crossing. Questions you need to ask yourself include what is this trace
and where does it go? Is it filtered at any point?

 

If GND2 is an internal layer then additional emissions should be minimal
provided GND1 remains solid.

 

HTH

James

 

 

 

James Pawson

EMC Problem Solver

 

Unit 3 Compliance

EMC Testing / Design for EMC / Problem Solving / Pre Compliance /
Consultancy / Environmental & Vibration

 

  www.unit3compliance.co.uk

07811 139957

2 Wellington Business Park,

New Lane, Bradford, BD4 8AL

 

From: Amund Westin mailto:am...@westin-emission.no> > 
Sent: 18 March 2020 08:38
To: EMC-PSTC@LISTSERV.IEEE.ORG  
Subject: [PSES] Stripline - discontinuity in adjacent ground planes

 

Let's say, part of a pcb stack looks like this  --- GND1 - SIGNAL - GND2

 

GND1 is solid copper fill

SIGNAL layer consists of high frequency lines LVDS, USB3.0, etc.

GND2 should be solid copper fill, but some traces are in that layer due to
space utilization reason. These traces are crossing 90 degrees the traces in
SIGNAL layer.

 

These traces in the GND2 will create gaps and therefore problems for the
return current for the high frequency lines I SINAL layer. 

 

But does it matter, as long as the GND1 layer is 100% filled, and there is
no disruption of the return current path for the traces in the adjacent
SIGNAL layer? 

 

 

Best regards

Amund Westin

 

 

-


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
mailto:emc-p...@ieee.org> >

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 mailto:sdoug...@ieee.org> >
Mike Cantwell mailto:mcantw...@ieee.org> > 

For policy questions, send mail to:
Jim Bacher mailto:j.bac...@ieee.org> >
David Heald mailto:dhe...@gmail.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:
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 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

[PSES] SV: [PSES] Stripline - discontinuity in adjacent ground planes

[Amund Westin]

Note that the worst situation may occur when both planes are equal,

 

In this PCB, they are more or less equal. It's an 8-layer stack (bottom/
Layer8=GND, Layer7=Signals, Layer6=GND, and .). But the signal traces in
Layer7 have now continuous return path in both L8 and L6.

 

Regards

Amund

 

.

 

 

 

 

Fra: Gert Gremmen 
Sendt: 18. mars 2020 09:52
Til: Amund Westin ; EMC-PSTC@LISTSERV.IEEE.ORG
Emne: Re: [PSES] Stripline - discontinuity in adjacent ground planes

 

Any signal flowing in the SIGNAL layer, will when getting to the load have
to choose between 2 ground layers. (when ordinary vias are used)

The signal layer with the lowest impedance is that where a good mutual
coupling between SIGNAL current and GNDX

is assured al along. So just verify the trace of SIGNAL in both GND's and
you have your answer.

Note that the worst situation may occur when both planes are equal, because
the ground current may

be cut in 2 parts and you lost easy control on what happens. Therefore use
just 1 ground plane only.

(in this 3 layer situation). Note that 1% corresponds to 40 dB, so if 99%
flows where you want it to,

1% may choose the wrong route and create a possible EMI problem and 40 dB
less is not much.

Buried via may be he answer to your plane problem, but does increase the
costs quite alot, where the 

single ground layer solution saves money.

The situation changes in 6 or 8 layer PCBS. There you will couple to the
closest

groundplane using buried vias only.

The generic answer is : control your return current, and avoid ambiguities.

Gert Gremmen

On 18-3-2020 9:38, Amund Westin wrote:

Let's say, part of a pcb stack looks like this  --- GND1 - SIGNAL - GND2

 

GND1 is solid copper fill

SIGNAL layer consists of high frequency lines LVDS, USB3.0, etc.

GND2 should be solid copper fill, but some traces are in that layer due to
space utilization reason. These traces are crossing 90 degrees the traces in
SIGNAL layer.

 

These traces in the GND2 will create gaps and therefore problems for the
return current for the high frequency lines I SINAL layer. 

 

But does it matter, as long as the GND1 layer is 100% filled, and there is
no disruption of the return current path for the traces in the adjacent
SIGNAL layer? 

 

 

Best regards

Amund Westin

 

 

-


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
mailto:emc-p...@ieee.org> >

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 mailto:sdoug...@ieee.org> >
Mike Cantwell mailto:mcantw...@ieee.org> > 

For policy questions, send mail to:
Jim Bacher mailto:j.bac...@ieee.org> >
David Heald mailto:dhe...@gmail.com> > 

-- 
Independent Expert on CE marking 
EMC Consultant
Electrical Safety Consultant

-

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:
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 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] ESD - Floating metal knob, otherwise grounded equipment

[Paolo Roncone]

Hi all,

in these cases (floating metal parts of EUT) we connect the floating part
to Earth Ground with a 2x 470kohm cable similar (or same) as that used for
VCP/HCP.

See IEC/EN 61000-4-2 sec. 7.2.4 Ungrounded Equipment:
"A cable with 470 kohm bleeder resistors, similar to the one used with the
HCP and VCP is the preferred device to remove charges; see 7.2"

Regards
Paolo

On Thu, Mar 12, 2020 at 7:08 PM Paasche, Dieter <
dieter.paas...@christiedigital.com> wrote:

> Hi
>
>
>
> I had a similar situation.  We ended using the alternative test method,
> with just extending the time between discharges. As per IEC 61000-42
> Section 7.4.2.1:
>
>
>
> Therefore as an alternative, the following options may be used:
>
> − the time interval between successive discharges shall be extended to
> the time necessary to allow natural decay of the charge from the EUT;
>
>
>
> Sincerely,
>
>
>
> Dieter Paasche
>
> Senior Product Developer, Electrical
>
> CHRISTIE
>
> 809 Wellington Street North
>
> Kitchener, ON N2G 4Y7
>
> Phone: 519-744-8005 ext.7211
>
> www.christiedigital.com
>
>
>
> This e-mail message (including attachments, if any) is confidential.  Any
> unauthorized use, distribution or disclosure is prohibited.  If you have
> received this e-mail message in error, please notify the sender by reply
> e-mail or telephone and delete it and any attachments from your computer
> system and records.
>
>
>
> *From:* DEREK WALTON <00734758d943-dmarc-requ...@ieee.org>
> *Sent:* Thursday, March 12, 2020 1:31 PM
> *To:* EMC-PSTC@LISTSERV.IEEE.ORG
> *Subject:* Re: [PSES] ESD - Floating metal knob, otherwise grounded
> equipment
>
>
>
> Oh Boy Elliott,
>
>
>
> you’ll get a few answers here, lol.
>
>
>
> My 10 cents is that when you are not discharging each time you are adding
> more and more charge to the isolated control, that eventually will snap
> over At that point you are discharging quite a significantly higher level
> of chart than an individual event.
>
>
>
> I would not call that a realistic “ compliance” test.
>
>
>
> OTOH, if it’s possible that may happen in the real world with an operator
> continually adding charge as they use your EUT, you may want to find a way
> of adding some way to bleed charge over a few seconds.
>
>
>
> Interesting problem, lets see what others say,
>
>
>
> Sincerely,
>
>
>
> Derek
>
> LFResearch and SSCLabs.com
> 
>
>
>
>
>
> On Mar 12, 2020, at 10:53 AM, Elliott Martinson <
> elliott.martin...@subzero.com> wrote:
>
>
>
> Hi Everybody,
>
>
>
> We’re having some disagreements regarding the 61000-4-2 standard. In the
> section “ungrounded equipment”, it states that ungrounded equipment or
> part(s) of equipment shall have the charge removed in between ESD pulses in
> order to not over-test.
>
> We have a product that only fails pre-compliance when repeated ESD pulses
> are applied to a floating metal knob without removing the charge in between
> (eventually there is a second discharge between the knob and the
> enclosure). The product as a whole is “grounded equipment”.
>
> Since the issue only happens when the charge isn’t removed in between
> pulses, is this a pass or a fail?
>
>
>
> Thanks,
>
>
>
> Elliott Martinson
>
> Controls Engineer
>
> Sub-Zero/Wolf
>
> elliott.martin...@subzero.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 <
> emc-p...@ieee.org>
>
> 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
> 

[PSES] Fwd: Emergency Stop Function

[Brian Kunde]

If any of you have a Case of Corrona, I hope it is the type that comes in
bottles or cans.

First, there is a guy in this group who I chatted with in the past who is
like an expert in the E-Stop function.  He has a Blog or Website dedicated
to this topic which I cannot currently find.  Can anyone help me get in
contact with him?

My area of need is with integrating the E-Stop function with a Variable
Frequency Drive (inverter).  I have to meet the international requirements
as well as the USA and Canadian requirements.

What I have is 3-phase AC power, through a Contactor, to a VFD, which
powers a 3-phase motor.  The VFD has the motor brake feature built in.
Under a normal STOP command, the VFD engages the motor brake.  All is
fine.

The VFD manufacturer's documentation shows to connect the E-STOP to the
motor Contactor which OPENs power to the VFD.  When the E-Stop is engaged,
power to the VFD is shut down; the motor continues to spin for up to 30
seconds or more before coming to a stop.  The motor Brake does not engage
because it is a feature of the VFD which is powered down.  This makes no
sense to me.

The E-STOP is supposed to stop motion as quickly as possible without
causing additional Risk (according to the MD and NFPA 79 cat.2).  So how is
the E-Stop function supposed to work with a VFD?  How is this typically
done?  Are we buying the wrong VFD?

Thanks to all.

The Other Brian

-

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:
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 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

[PSES] Product Safety Job Opportunity at Thermo Fisher Scientific - Boston Area

[Kapur, Ken]

We have the following product safety/ compliance position currently open in the 
Boston, MA area.

Product Safety and Compliance Specialist job in Chelmsford, Massachusetts at 
Thermo Fisher Scientific:
https://jobs.thermofisher.com/global/en/job/114265BR/Product-Safety-and-Compliance-Specialist



  *   Responsible for the coordination, evaluation and implementation of 
division's regulatory strategy and compliance programs through the review, 
consultation, training and support of each discipline (Engineering, Operations, 
Quality, Sales, Sourcing etc) to fulfill their business goals in a compliant 
manner.
  *   Liaise between the respective disciplines and 3rd Party regulatory 
agencies (UL, CSA, TUV, Notified Bodies, FDA, ISO registrars, etc) and ensures 
this interaction follows the established best practice model for the division.
  *   Should have a working knowledge of and eagerness to expand knowledge of 
the applicable standards and regulations that apply to division  (product 
safety standards like IEC 61010-1, EMC standards, etc) to filter and 
disseminate applicable information to the respective disciplines inside 
division and the regulatory agencies for a consistent compliance approach.


Go ahead and send me a note if interested.


Best Regards,
Ken Kapur
Director, Global Product Compliance
Thermo Fisher Scientific
ken.ka...@thermofisher.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:
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 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] **External**[PSES] Fwd: Emergency Stop Function

[Jim Hulbert]

I think you need a VFD with Safe Torque Off (STO) function.

Jim Hulbert

From: Brian Kunde [mailto:bkundew...@gmail.com]
Sent: Thursday, March 19, 2020 1:19 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: **External**[PSES] Fwd: Emergency Stop Function


If any of you have a Case of Corrona, I hope it is the type that comes in 
bottles or cans.

First, there is a guy in this group who I chatted with in the past who is like 
an expert in the E-Stop function.  He has a Blog or Website dedicated to this 
topic which I cannot currently find.  Can anyone help me get in contact with 
him?

My area of need is with integrating the E-Stop function with a Variable 
Frequency Drive (inverter).  I have to meet the international requirements as 
well as the USA and Canadian requirements.

What I have is 3-phase AC power, through a Contactor, to a VFD, which powers a 
3-phase motor.  The VFD has the motor brake feature built in. Under a normal 
STOP command, the VFD engages the motor brake.  All is fine.

The VFD manufacturer's documentation shows to connect the E-STOP to the motor 
Contactor which OPENs power to the VFD.  When the E-Stop is engaged, power to 
the VFD is shut down; the motor continues to spin for up to 30 seconds or more 
before coming to a stop.  The motor Brake does not engage because it is a 
feature of the VFD which is powered down.  This makes no sense to me.

The E-STOP is supposed to stop motion as quickly as possible without causing 
additional Risk (according to the MD and NFPA 79 cat.2).  So how is the E-Stop 
function supposed to work with a VFD?  How is this typically done?  Are we 
buying the wrong VFD?

Thanks to all.

The Other Brian
-


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 
mailto:emc-p...@ieee.org>>

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 mailto:sdoug...@ieee.org>>
Mike Cantwell mailto:mcantw...@ieee.org>>

For policy questions, send mail to:
Jim Bacher mailto:j.bac...@ieee.org>>
David Heald mailto:dhe...@gmail.com>>

This email message may contain confidential, proprietary and/or privileged 
information. It is intended only for the use of the intended recipient(s). If 
you have received it in error, please immediately advise the sender by reply 
email and then delete this message. No one 

Re: [PSES] Fwd: Emergency Stop Function

[MIKE]

Brian —
Look on the web for Doug Nix. Good guy, knows his stuff.
Mike

Sent from XFINITY Connect Mobile App

-- Original Message --

From: Brian Kunde
To: EMC-PSTC@LISTSERV.IEEE.ORG
Sent: March 19, 2020 at 12:19 PM
Subject: [PSES] Fwd: Emergency Stop Function

If any of you have a Case of Corrona, I hope it is the type that comes in 
bottles or cans.

First, there is a guy in this group who I chatted with in the past who is like 
an expert in the E-Stop function. He has a Blog or Website dedicated to this 
topic which I cannot currently find. Can anyone help me get in contact with him?

My area of need is with integrating the E-Stop function with a Variable 
Frequency Drive (inverter). I have to meet the international requirements as 
well as the USA and Canadian requirements.

What I have is 3-phase AC power, through a Contactor, to a VFD, which powers a 
3-phase motor. The VFD has the motor brake feature built in. Under a normal 
STOP command, the VFD engages the motor brake. All is fine.

The VFD manufacturer's documentation shows to connect the E-STOP to the motor 
Contactor which OPENs power to the VFD. When the E-Stop is engaged, power to 
the VFD is shut down; the motor continues to spin for up to 30 seconds or more 
before coming to a stop. The motor Brake does not engage because it is a 
feature of the VFD which is powered down. This makes no sense to me.

The E-STOP is supposed to stop motion as quickly as possible without causing 
additional Risk (according to the MD and NFPA 79 cat.2). So how is the E-Stop 
function supposed to work with a VFD? How is this typically done? Are we buying 
the wrong VFD?

Thanks to all.

The Other Brian -


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-p...@ieee.org (mailto:emc-p...@ieee.org)

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) 
(http://www.ieee-pses.org/list.html)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas sdoug...@ieee.org (mailto:sdoug...@ieee.org)
Mike Cantwell mcantw...@ieee.org (mailto:mcantw...@ieee.org)

For policy questions, send mail to:
Jim Bacher j.bac...@ieee.org (mailto:j.bac...@ieee.org)
David Heald dhe...@gmail.com (mailto:dhe...@gmail.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:
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 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] **External**[PSES] Fwd: Emergency Stop Function

[David Nyffenegger]

Brian,



Depending on your requirement you may need a risk assessment to something
like ISO 12100 or ISO 13849-1.  From that would be determined the minimum
performance level of the safety control system.  A single contactor could
be used as the VFD manufacturer suggests. For higher performance levels two
contactors in series with monitoring of the contacts may be required.   But
the contactor is brute force and doesn’t allow for controlled shutdown as
you have noted.  A VFD with STO input is an easier and cleaner approach and
allows controlled shutdown providing the performance level of the STO is
adequate for your requirements.  There more books, white papers, and
seminars than you can imagine on this topic.  The OEMs of the safety
control system components are more than happy to share their view and
documentation on the subject.



Note that a fundamental general requirement for an E-STOP is that releasing
the E-STOP does not in itself restart any motion.  If you are dropping a
VFD with a contactor or STO it will probably not re-start when the E-STOP
is released.  But in other cases a safety controller may be appropriate to
use with the E-STOP and STO or contactors.


-Dave

On Thu, Mar 19, 2020 at 1:31 PM Jim Hulbert 
wrote:

> I think you need a VFD with Safe Torque Off (STO) function.
>
>
>
> Jim Hulbert
>
>
>
> *From:* Brian Kunde [mailto:bkundew...@gmail.com]
> *Sent:* Thursday, March 19, 2020 1:19 PM
> *To:* EMC-PSTC@LISTSERV.IEEE.ORG
> *Subject:* **External**[PSES] Fwd: Emergency Stop Function
>
>
>
>
>
> If any of you have a Case of Corrona, I hope it is the type that comes in
> bottles or cans.
>
>
>
> First, there is a guy in this group who I chatted with in the past who is
> like an expert in the E-Stop function.  He has a Blog or Website dedicated
> to this topic which I cannot currently find.  Can anyone help me get in
> contact with him?
>
>
>
> My area of need is with integrating the E-Stop function with a Variable
> Frequency Drive (inverter).  I have to meet the international requirements
> as well as the USA and Canadian requirements.
>
>
>
> What I have is 3-phase AC power, through a Contactor, to a VFD, which
> powers a 3-phase motor.  The VFD has the motor brake feature built in.
> Under a normal STOP command, the VFD engages the motor brake.  All is
> fine.
>
>
>
> The VFD manufacturer's documentation shows to connect the E-STOP to the
> motor Contactor which OPENs power to the VFD.  When the E-Stop is engaged,
> power to the VFD is shut down; the motor continues to spin for up to 30
> seconds or more before coming to a stop.  The motor Brake does not engage
> because it is a feature of the VFD which is powered down.  This makes no
> sense to me.
>
>
>
> The E-STOP is supposed to stop motion as quickly as possible without
> causing additional Risk (according to the MD and NFPA 79 cat.2).  So how is
> the E-Stop function supposed to work with a VFD?  How is this typically
> done?  Are we buying the wrong VFD?
>
>
>
> Thanks to all.
>
>
>
> The Other Brian
>
> -
> 
>
> 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-p...@ieee.org>
>
> 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)
>