RE: Safety regulations
Bonjour Benoit: The devil is in the details. If the Card Cage is LISTED and it has a particular model number and now you add data cards to it and you sell the Card Cage under a different model numbers ( that will vary depending upon your various configurations ) the Card Cage then becomes no longer LISTED. You have to advise UL and have them include all of the new model numbers in the LISTING and provide info as to what that changes are.*and that will cost you about 800 US DOLLARS. ALL OF THE ABOVE PRESUPPOSES THAT YOU ARE THE APPLICANT ( THE OWNER OF THE FILE ) . Best Regards Reg Henry Reginald Henry Electrical Engineer Please think before printing this e-mail Tel: (631) 952-2288Ext: 310 Tel: (800) 645-9116Ext: 310 Web: <http://www.vicon-cctv.com/ http://www.vicon-cctv.com/> >< /U> From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of rn...@san.rr.com Sent: Friday, May 02, 2008 2:21 PM To: 'Benoit Nadeau' Cc: 'EMC-PSTC' Subject: RE: Safety regulations Bonjour Benoit: If a PCB manufacturer buys a card cage that includes a fully listed power supply (approved by UL or CSA or ETL or any NRTL), and stuff this cage with his own PCBs (not listed) with no harmful external voltages or access to, and resell this as a whole new product. Can he put that on the market without having to re-list the new product as long as the markings on the power supply are still visible from outside the box? If the card cage is LISTED, then probably okay. If a product is LISTED, then it meets safety requirements for its intended purpose, namely a card cage with cards provided by another entity. Be careful that the card cage is LISTED rather than RECOGNIZED. If RECOGNIZED, then it is intended as a part of some host equipment, and the host equipment will need to be independently certified (LISTED). If the card cage is LISTED, and you put another name on it to make it look like a different product, or make it look like another manufacturer, then you will need to get a "COMPLEMENTARY LISTING." This is where t he certification house lists both you and the card cage as manufacturers, and that the card cage manufacturer is the actual manufacturer. I hope this answers your question. Best regards, Rich - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/em c-pstc CONFIDENTIALITY NOTICE: This transmission may contain information that is privileged, confidential and/or exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information contained herein (including any reliance thereof) is strictly prohibited. If you receive this transmission in error, please immediately contact the sender and destroy the material in it's entireity, whether in electronic or hard copy format.The views expressed in this communication may not necessarily be the views held by the company. Thank you.
Re: Safety regulations
On May 1, 2008, at 8:37 AM, Benoit Nadeau wrote: So the question is: If a PCB manufacturer buys a card cage that includes a fully listed power supply (approved by UL or CSA or ETL or any NRTL), and stuff this cage with his own PCBs (not listed) with no harmful external voltages or access to, and resell this as a whole new product. Can he put that on the market without having to re-list the new product as long as the markings on the power supply are still visible from outside the box? I think there are two or three answers. 1)The label on the power supply pertains to the supply and the card cage. It says nothing about the cards placed within it. If the system (cards, card cage, and power supply) needs a safety approval then the cards must have their own approval. 2)There is no uniform requirement for safety approvals in the USA. Certain municipalities require safety approvals, and many customers require them. However (with the exception of telecom equipment) there is no federal requirement (although OSHA has requirements as noted in another message). Most manufacturers conduct safety approvals to enable their products to be sold everywhere and to anyone. The manufacturer needs to determine the safety standard appropriate for the product based on the market. Most manufacturers consider it a good investment to have a third party do the approval. This validates the design and is helpful in the case of litigation. ; 3)Every product has a manual and product documentation which states approvals. If you have your own designs inside the card cage then in my opinion they need approval before you can claim anything about safety. If you claim nothing about safety then I would take pains to ensure customers do not see the power supply approval label as saying anything about the cards. Curt - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Safety regulations
Bonjour Benoit: If a PCB manufacturer buys a card cage that includes a fully listed power supply (approved by UL or CSA or ETL or any NRTL), and stuff this cage with his own PCBs (not listed) with no harmful external voltages or access to, and resell this as a whole new product. Can he put that on the market without having to re-list the new product as long as the markings on the power supply are still visible from outside the box? If the card cage is LISTED, then probably okay. If a product is LISTED, then it meets safety requirements for its intended purpose, namely a card cage with cards provided by another entity. Be careful that the card cage is LISTED rather than RECOGNIZED. If RECOGNIZED, then it is intended as a part of some host equipment, and the host equipment will need to be independently certified (LISTED). If the card cage is LISTED, and you put another name on it to make it look like a different product, or make it look like another manufacturer, then you will need to get a "COMPLEMENTARY LISTING." This is where the certification house lists both you and the card cage as manufacturers, and that the card cage manufacturer is the actual manufacturer. I hope this answers your question. Best regards, Rich - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald: emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Safety regulations
Hi Benoit, You state that the built-in power supply is “fully listed and approved by UL or CSA or ETL or any NRTL” (I’m not sure what that statement actually means). Generally, such a power supply is not Listed, but is a Recognized Component and as such it likely has Conditions of Acceptability associated with the Recognition meaning that the power supply must have those conditions addressed in the end system by the system manufacturer to satisfy those safety concerns. I am a bit amazed that OSHA regulations haven’t been brought into this discussion before this, but as a “card cage” type of product, is this product intended to be marketed within the US workplace and is it not considered to be a consumer product? If so, then OSHA regulations from 29CFR Part 1910 Subpart S would apply. Regardless of circuit class and excerpt from 29CFR Part 1910 Subpart S (1910.399) specifically states: “Acceptable. An installation or equipment is acceptable to the Assistant Secretary of Labor, and approved within the meaning of this Subpart S: (1) If it is accepted, or certified, or listed, or labeled, or otherwise determined to be safe by a nationally recognized testing laboratory recognized pursuant to § 1910.7; or (2) With respect to an installation or equipment of a kind that no nationally recognized testing laboratory accepts, certifies, lists, labels, or determines to be safe, if it is inspected or tested by another Federal agency, or by a State, municipal, or other local authority responsible for enforcing occupational safety provisions of the National Electrical Code, and found in compliance with the provisions of the National Electrical Code as applied in this subpart; or (3) With respect to custom-made equipment or related installations that are designed, fabricated for, and intended for use by a particular customer, if it is determined to be safe for its intended use by its manufacturer on the basis of test data which the employer keeps and makes available for inspection to the Assistant Secretary and his authorized representatives.” So, if the “whole new product” is to be intended for the US workplace, then any of the 3 conditions above must be applied. Marketing such a system into the workplace without first being acceptable to OSHA could introduce liability(ies) to the marketer/integrator. And, consumer products don’t need to adhere to OSHA regulations, but it would be wise to exercise due diligence in regard to this product’s safety to reduce any safety liabilities to the user, integrator and/or marketer. Please note that this is pure speculation (educated guess?) since there was not enough information provided in your original product description to formulate a sound response. Comments? Best regards, Ron Pickard RPQ Consulting 7372 West Luke Avenue Glendale, AZ 85303 +623.512-3451 tel, +623.848-9033 fax rpick...@rpqconsulting.com www.rpqconsulting.com From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Benoit Nadeau Sent: Thursday, May 01, 2008 6:38 AM To: EMC-PSTC Subject: Safety regulations Bonjour, I’m much more fluent in EMC than safety and this is why I respectfully seek advice in this matter. I have a question coming from the designers and I’ve been looking in the US regulations (the NEC mainly) to find the answer but I didn’t. I think this is more like an interpretation than anything else. So the question is: If a PCB manufacturer buys a card cage that includes a fully listed power supply (approved by UL or CSA or ETL or any NRTL), and stuff this cage with his own PCBs (not listed) with no harmful external voltages or access to, and resell this as a whole new product. Can he put that on the market without having to re-list the new product as long as the markings on the power supply are still visible from outside the box? For me this would be like having an external Power Supply that feeds very low voltage to a box (like a laptop computer), Thank you for the time you are going to take to answer this. Regards, == Benoit Nadeau, ing. M.ing. Gérant du Groupe Conformité (Conformity Group Manager) Matrox 1055 boul. St-Régis Dorval (Québec) Canada H9P 2T4 Tél: (514) 822-6000 (2475) FAX: (514) 822-6275 bnad...@matrox.com www.matrox.com == - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.
RE: Safety regulations
> From: Benoit Nadeau > Sent: Thursday, May 01, 2008 6:38 AM > > If a PCB manufacturer buys a card cage that includes a fully > listed power supply (approved by UL or CSA or ETL or any > NRTL), and stuff this cage with his own PCBs (not listed) > with no harmful external voltages or access to, and resell > this as a whole new product. Can he put that on the market > without having to re-list the new product as long as the > markings on the power supply are still visible from outside the box? I think you can tell from the speculative nature of the responses so far that You don't provide enough information about the approval of the power supply or its electrical ratings for sound advice. If the responses haven't already provided you with the guidance you were seeking, please be more specific. Also, provide the details of the certification markings on the power supply, since it's unusual, though not unheard of, for a 'fully approved' power supply to be used in an application for building into a card cage. Regards, Peter L. Tarver, PE ptar...@ieee.org CONFIDENTIALITY This e-mail message and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail message, you are hereby notified that any dissemination, distribution or copying of this e-mail message, and any attachments thereto, is strictly prohibited. If you have received this e-mail message in error, please immediately notify the sender and permanently delete the original and any copies of this email and any prints thereof. ABSENT AN EXPRESS STATEMENT TO THE CONTRARY HEREINABOVE, THIS E-MAIL IS NOT INTENDED AS A SUBSTITUTE FOR A WRITING. Notwithstanding the Uniform Electronic Transactions Act or the applicability of any other law of similar substance and effect, absent an express statement to the contrary hereinabove, this e-mail message its contents, and any attachments hereto are not intended to represent an offer or acceptance to enter into a contract and are not otherwise intended to bind the sender, Sanmina-SCI Corporation (or any of its subsidiaries), or any other person or entity. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Safety regulations
> From: Curt McNamara > Sent: Friday, May 02, 2008 7:38 AM > > Wow! The chart shows 2A at 45V for Class II, or 100VA as you > note. This is a lot of energy to me, and can certainly result > in ignition given the correct conditions. Perhaps, but not enough to start a fire, cause an electric shock (in dry conditions). Keep in mind that the 45 V, the 2 A and the 100 VA are note measured at the same loading condition are unlikely to occur simultaneously. Voltage is most often open-circuit, current is at some very low impedance load condition (possibly a short-circuit) and power is into a Thevenin equivalent impedance. > I note that the > standard also shows voltages above SELV as permissible. You don't specify a standard, but presumably you're referring to 60950-1. While the OP failed to mention any voltage, current or power output from the "Listed" power supply, it's most probably limited to SELV, though not necessarily to LPS (an approximation of NEC Class 2). > The implication in the original question was information > technology (as far as I could tell). Even with approved > supplies and only SELV levels safety investigations are still > required. Not necessarily. Ted's proposition that a Class 2 or LPS output power supply would not *require* a safety evaluation was accurate. A safety evaluation might be a wiser course, but it's not strictly necessary. > Some examples: > Flammable material (the laptop plastic case). > Fault (5V to ground) causes part to fall off board through > vent hole, igniting material on table. > There are lots of ways to design unsafe products using only > SELV (not even considering Class II). Or without using any electricity. Though I think your point might have been that SELV alone is insufficient rationale to not perform a safety evaluation, since SELV has no current or power limitations associated with it. SELV alone only addresses electric shock, not fire or energy hazards. Nonetheless, Ted's proposition was correct, unless the product contains some other type of circuit that draws the product into a different category of equipment, where evaluations are required, regardless of voltage input. Telecom equipment is a good example. In some markets, radio equipment. Regards, Peter L. Tarver, PE ptar...@ieee.org CONFIDENTIALITY This e-mail message and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail message, you are hereby notified that any dissemination, distribution or copying of this e-mail message, and any attachments thereto, is strictly prohibited. If you have received this e-mail message in error, please immediately notify the sender and permanently delete the original and any copies of this email and any prints thereof. ABSENT AN EXPRESS STATEMENT TO THE CONTRARY HEREINABOVE, THIS E-MAIL IS NOT INTENDED AS A SUBSTITUTE FOR A WRITING. Notwithstanding the Uniform Electronic Transactions Act or the applicability of any other law of similar substance and effect, absent an express statement to the contrary hereinabove, this e-mail message its contents, and any attachments hereto are not intended to represent an offer or acceptance to enter into a contract and are not otherwise intended to bind the sender, Sanmina-SCI Corporation (or any of its subsidiaries), or any other person or entity. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Safety regulations
Where is limited power/voltage/current required for Class II construction ? Did you intend to say Class 2 power source ? luck, Brian From: emc-p...@ieee.org [mailto:emc-p...@ieee.org]On Behalf Of Curt McNamara Sent: Friday, May 02, 2008 7:38 AM To: ted.eck...@apcc.com Cc: emc-p...@ieee.org Subject: Re: Safety regulations Wow! The chart shows 2A at 45V for Class II, or 100VA as you note. This is a lot of energy to me, and can certainly result in ignition given the correct conditions. I note that the standard also shows voltages above SELV as permissible. The implication in the original question was information technology (as far as I could tell). Even with approved supplies and only SELV levels safety investigations are still required. Some examples: Flammable material (the laptop plastic case). Fault (5V to ground) causes part to fall off board through vent hole, igniting material on table. There are lots of ways to design unsafe products using only SELV (not even considering Class II). If your product needs a safety approval then an investigation is required. To phrase this another way: someone else's label (the power supply manufacturer) is not a valid indicator that a product has a safety approval. Curt For help, send mail to the list administrators: - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
RE: Safety regulations
LPS designated power supplies are specified for ITE when there is no fire
enclosure (i.e., plastic enclosure not qualified for fire enclosure).
Other standards achieve fire protection by specifying a maximum of 15W power
source if there is no fire enclosure (IEC 60065).
Don Umbdenstock
Manager Compliance Engineering
Tyco Safety Products / Sensormatic
6600 Congress Avenue
Boca Raton, FL 33487 USA
Phone: 561.912.6440
djumbdenst...@tycoint.com <mailto:djumbdenst...@tycoint.com>
From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Curt McNamara
Sent: Friday, May 02, 2008 10:38 AM
To: ted.eck...@apcc.com
Cc: emc-p...@ieee.org
Subject: Re: Safety regulations
Wow! The chart shows 2A at 45V for Class II, or 100VA as you note. This is a
lot of energy to me, and can certainly result in ignition given the correct
conditions. I note that the standard also shows voltages above SELV as
permissible.
The implication in the original question was information technology (as far as
I could tell). Even with approved supplies and only SELV levels safety
investigations are still required.
Some examples:
Flammable material (the laptop plastic case).
Fault (5V to ground) causes part to fall off board through vent hole, igniting
material on table.
There are lots of ways to design unsafe products using only SELV (not even
considering Class II). If your product needs a safety approval then an
investigation is required.
To phrase this another way: someone else's label (the power supply
manufacturer) is not a valid indicator that a product has a safety approval.
Curt
in real life
Curt McNamara, P.E. // principal electrical engineer
Logic Product Development
411 Washington Ave. N. Suite 400
Minneapolis, MN 55401
T // 612.436.5178
F // 612.672.9489
_www.logicpd.com_ http://www.logicpd.com/>
On May 2, 2008, at 7:24 AM, ted.eck...@apcc.com wrote:
The output of a Class 2/LPS circuit does not have the voltage or energy to
be a shock or ignition risk as long as that voltage is used without any
changes. I could design a circuit with an inverter and step-up transformer
that would give me a hazardous voltage. The Class 2 limit is 100 W. In
theory, I could get 1000 VAC RMS at 100 mA. Even with losses due
efficiency limits, there would be enough current to kill somebody.
I will say that in general, if you are using a power supply that meets the
60950 LPS or the NEC Class 2 limits (they are basically the same) then you
can hang circuits off the output without problems. However, it still needs
to be investigated in a case by case basis.
Ted Eckert
APC-MGE
http://www.apc.com/
The items contained in this e-mail reflect the personal opinions of the
writer and are only provided for the assistance of the reader. The writer
is not speaking in an official capacity for APC-MGE or Schneider Electric.
The speaker does not represent APC-MGE's or Schneider Electric's official
position on any matter.
scott barrows
To
Sent by: Curt McNamara ,
emc-p...@ieee.org peter merguerian
cc
05/02/2008 07:10 Benoit Nadeau ,
AMEMC-PSTC
Subject
Re: Safety regulations
If the power supply is an NEC class 2 (vs a class II insulation system) or
an LPS construction, then there is not enough current available to be a
fire hazard.
Scott
Curt McNamara wrote:
What if a short occurred on one of these PCBs? Is there enough flammable
material to constitute a fire hazard? Could a component get hot enough to
melt connections and drop off, igniting material underneath the product?
As you can see, there may be other cases to consider. Given that an event
could initiate legal action, it may be wise to have a third party verify
safety.
Curt
On May 1, 2008, at 10:37 PM, peter merguerian wrote:
If the power supply is Listed/Certified Class 2 (power limited
outputs) and there are no hazardous energy levels, I see no
problems.
Peter Merguerian
Benoit Nadeau wrote:
Bonjour,
I’m much more fluent in EMC than safety and this is why I
respectfully seek advice in this matter.
I have a question coming from the designers and I’ve been looking in
the US regulations (the NEC mainly) to find the answer but I didn’t.
I think this is more like an interpretation than anyt
RE: Safety regulations
Curt writes:
To phrase this another way: someone else's label (the power supply
manufacturer) is not a valid indicator that a product has a safety approval.
If I understand the original question correctly, this is what it really comes
down to. The power supply may be Listed by itself, but that does not mean that
the end product using it is then somehow covered by the power supply Listing,
even if no additional hazards are present in the end product outside the power
supply. If there is a requirement for the end product to be Listed, then it
must be evaluated separately. Allowing the power supply Listing mark to be
visible in the end product in such a way that the customer is led to believe
that this mark covers the end product is a no-no.
Scott Aldous
Compliance Engineer
Advanced Energy
Tel: 970-407-6872
Fax: 970-407-5872
From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Curt McNamara
Sent: Friday, May 02, 2008 8:38 AM
To: ted.eck...@apcc.com
Cc: emc-p...@ieee.org
Subject: Re: Safety regulations
Wow! The chart shows 2A at 45V for Class II, or 100VA as you note. This is a
lot of energy to me, and can certainly result in ignition given the correct
conditions. I note that the standard also shows voltages above SELV as
permissible.
The implication in the original question was information technology (as far as
I could tell). Even with approved supplies and only SELV levels safety
investigations are still required.
Some examples:
Flammable material (the laptop plastic case).
Fault (5V to ground) causes part to fall off board through vent hole, igniting
material on table.
There are lots of ways to design unsafe products using only SELV (not even
considering Class II). If your product needs a safety approval then an
investigation is required.
To phrase this another way: someone else's label (the power supply
manufacturer) is not a valid indicator that a product has a safety approval.
Curt
in real life
Curt McNamara, P.E. // principal electrical engineer
Logic Product Development
411 Washington Ave. N. Suite 400
Minneapolis, MN 55401
T // 612.436.5178
F // 612.672.9489
_www.logicpd.com_ http://www.logicpd.com/>
On May 2, 2008, at 7:24 AM, ted.eck...@apcc.com wrote:
The output of a Class 2/LPS circuit does not have the voltage or energy to
be a shock or ignition risk as long as that voltage is used without any
changes. I could design a circuit with an inverter and step-up transformer
that would give me a hazardous voltage. The Class 2 limit is 100 W. In
theory, I could get 1000 VAC RMS at 100 mA. Even with losses due
efficiency limits, there would be enough current to kill somebody.
I will say that in general, if you are using a power supply that meets the
60950 LPS or the NEC Class 2 limits (they are basically the same) then you
can hang circuits off the output without problems. However, it still needs
to be investigated in a case by case basis.
Ted Eckert
APC-MGE
http://www.apc.com/
The items contained in this e-mail reflect the personal opinions of the
writer and are only provided for the assistance of the reader. The writer
is not speaking in an official capacity for APC-MGE or Schneider Electric.
The speaker does not represent APC-MGE's or Schneider Electric's official
position on any matter.
scott barrows
To
Sent by: Curt McNamara ,
emc-p...@ieee.org peter merguerian
cc
05/02/2008 07:10 Benoit Nadeau ,
AMEMC-PSTC
Subject
Re: Safety regulations
If the power supply is an NEC class 2 (vs a class II insulation system) or
an LPS construction, then there is not enough current available to be a
fire hazard.
Scott
Curt McNamara wrote:
What if a short occurred on one of these PCBs? Is there enough flammable
material to constitute a fire hazard? Could a component get hot enough to
melt connections and drop off, igniting material underneath the product?
As you can see, there may be other cases to consider. Given that an event
could initiate legal action, it may be wise to have a third party verify
safety.
Curt
On May 1, 2008, at 10:37 PM, peter merguerian wrote:
If the power supply is Listed/Certified Class 2 (power limited
outputs) and there are no hazardous energy levels, I see no
problems.
Peter Merguerian
Re: Safety regulations
Wow! The chart shows 2A at 45V for Class II, or 100VA as you note. This is a
lot of energy to me, and can certainly result in ignition given the correct
conditions. I note that the standard also shows voltages above SELV as
permissible.
The implication in the original question was information technology (as far as
I could tell). Even with approved supplies and only SELV levels safety
investigations are still required.
Some examples:
Flammable material (the laptop plastic case).
Fault (5V to ground) causes part to fall off board through vent hole, igniting
material on table.
There are lots of ways to design unsafe products using only SELV (not even
considering Class II). If your product needs a safety approval then an
investigation is required.
To phrase this another way: someone else's label (the power supply
manufacturer) is not a valid indicator that a product has a safety approval.
Curt
in real life
Curt McNamara, P.E. // principal electrical engineer
Logic Product Development
411 Washington Ave. N. Suite 400
Minneapolis, MN 55401
T // 612.436.5178
F // 612.672.9489
_www.logicpd.com_ http://www.logicpd.com/>
On May 2, 2008, at 7:24 AM, ted.eck...@apcc.com wrote:
The output of a Class 2/LPS circuit does not have the voltage or energy
to
be a shock or ignition risk as long as that voltage is used without any
changes. &nbs p;I could design a circuit with an inverter and step-up
transformer
that would give me a hazardous voltage. The Class 2 limit is 100 W. In
theory, I could get 1000 VAC RMS at 100 mA. Even with losses due
efficiency limits, there would be enough current to kill somebody.
I will say that in general, if you are using a power supply that meets
the
60950 LPS or the NEC Class 2 limits (they are basically the same) then
you
can hang circuits off the output without problems. However, it still
needs
to be investigated in a case by case basis.
Ted Eckert
APC-MGE
http://www.apc.com/
The items contained in this e-mail reflect the personal opinions of the
writer and are only provided for the assistance of the reader. The
writer
is not speaking in an official capacity for APC-MGE or Schneider
Electric.
The speaker does not represent APC-MGE's or Schneider Electric's
official
p osition on any matter.
scott barrows
& nbsp;
To
Sent by: Curt McNamara ,
emc-p...@ieee.org peter merguerian
&nb sp;
cc
05/02/2008 07:10 Benoit Nadeau
,
AMEMC-PSTC
&nb sp;
Subject
Re: Safety regulations
If the power supply is an NEC class 2 (vs a class II insulation system)
or
an LPS construction, then there is not enough current available to be a
fire hazard.
Scott
Curt McNamara wrote:
What if a short occu rred on one of these PCBs? Is there enough
flammable
material to constitute a fire hazard? Could a component get hot enough
to
melt connections and drop off, igniting material underneath the product?
As you can see, there may be other cases to consider. Given that an
event
could initiate legal action, it may be wise to have a third party verify
safety.
Curt
On May 1, 2008, at 10:37 PM, peter merguerian wrote:
If the power supply is Listed/Certified Class 2 (power limited
outputs) and there are no hazardous energy levels, I see no
problems.
Peter Merguerian
Benoit Nadeau wrote:
Bonjour,
I’m much more fluent in EMC t han safety and this is why I
respectfully seek advice in this matter.
I have a question coming from the designers and I’ve been looking
in
the US regulations (the NEC mainly) to find the answer but I
didn’t.
I think this is more like an interpretation than anything else.
So the question is:
If a PCB manufacturer buys a card cage that includes a fully
listed
power suppl
Re: Safety regulations
This message has been converted via the evaluation version of Transend Migrator. Use beyond the trial period specified in your Software Evaluation Agreement is prohibited. Please contact Transend Corporation at (650) 324-5370 or sales.i...@transend.com to obtain a license suitable for use in a production environment. Thank you. - In message , dated Fri, 2 May 2008, ted.eck...@apcc.com writes: >I will say that in general, if you are using a power supply that meets >the 60950 LPS or the NEC Class 2 limits (they are basically the same) >then you can hang circuits off the output without problems. However, >it still needs to be investigated in a case by case basis. There is also the matter of stored energy. The input power may be only 1 W, but if the energy is stored over time in batteries and/or very high-value capacitors, there is a hazard. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Murphy's Law has now been officially re-named The Certainty Principle John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list.Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org For policy questions, send mail to: Jim Bacher: j.bac...@ieee.org David Heald:emc-p...@daveheald.com All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: Safety regulations
This message has been converted via the evaluation version of
Transend Migrator. Use beyond the trial period specified in
your Software Evaluation Agreement is prohibited. Please contact
Transend Corporation at (650) 324-5370 or sales.i...@transend.com
to obtain a license suitable for use in a production environment.
Thank you.
-
The output of a Class 2/LPS circuit does not have the voltage or energy to
be a shock or ignition risk as long as that voltage is used without any
changes. I could design a circuit with an inverter and step-up transformer
that would give me a hazardous voltage. The Class 2 limit is 100 W. In
theory, I could get 1000 VAC RMS at 100 mA. Even with losses due
efficiency limits, there would be enough current to kill somebody.
I will say that in general, if you are using a power supply that meets the
60950 LPS or the NEC Class 2 limits (they are basically the same) then you
can hang circuits off the output without problems. However, it still needs
to be investigated in a case by case basis.
Ted Eckert
APC-MGE
http://www.apc.com/
The items contained in this e-mail reflect the personal opinions of the
writer and are only provided for the assistance of the reader. The writer
is not speaking in an official capacity for APC-MGE or Schneider Electric.
The speaker does not represent APC-MGE's or Schneider Electric's official
position on any matter.
scott barrows
To
Sent by: Curt McNamara ,
emc-p...@ieee.org peter merguerian
cc
05/02/2008 07:10 Benoit Nadeau ,
AMEMC-PSTC
Subject
Re: Safety regulations
If the power supply is an NEC class 2 (vs a class II insulation system) or
an LPS construction, then there is not enough current available to be a
fire hazard.
Scott
Curt McNamara wrote:
What if a short occurred on one of these PCBs? Is there enough flammable
material to constitute a fire hazard? Could a component get hot enough to
melt connections and drop off, igniting material underneath the product?
As you can see, there may be other cases to consider. Given that an event
could initiate legal action, it may be wise to have a third party verify
safety.
Curt
On May 1, 2008, at 10:37 PM, peter merguerian wrote:
If the power supply is Listed/Certified Class 2 (power limited
outputs) and there are no hazardous energy levels, I see no
problems.
Peter Merguerian
Benoit Nadeau wrote:
Bonjour,
I’m much more fluent in EMC than safety and this is why I
respectfully seek advice in this matter.
I have a question coming from the designers and I’ve been looking in
the US regulations (the NEC mainly) to find the answer but I didn’t.
I think this is more like an interpretation than anything else.
So the question is:
If a PCB manufacturer buys a card cage that includes a fully listed
power supply (approved by UL or CSA or ETL or any NRTL), and stuff
this cage with his own PCBs (not listed) with no harmful external
voltages or access to, and resell this as a whole new product. Can
he put that on the market without having to re-list the new product
as long as the markings on the power supply are still visible from
outside the box?
For me this would be like having an external Power Supply that feeds
very low voltage to a box (like a laptop computer),
Thank you for the time you are going to take to answer this.
Regards,
==
Benoit Nadeau, ing. M.ing.
Gérant du Groupe Conformité (Conformity Group Manager)
Matrox
1055 boul. St-Régis
Dorval (Québec)
Canada H9P 2T4
Tél: (514) 822-6000 (2475)
FAX: (514) 822-6275
bnad...@matrox.com
www.
