To further add to the discussion, Subpart C of the FCC part 15 deals with intentional radiators. The limits there have no Class A or B differentiation, but do refer the limits specified as the general limits. So a comparison between the limits in Subpart C and Subpart B (unintentional radiators) finds that the general limits and the Class B limits are the same. Oh myy, what does that imply ??
In an emergency vehicle, that you might find yourself, or your child, in as a patient, as the medics are trying to pick up your heart ECG and transmit it to the hospital so the Doc's can prep for your case when you arrive, and all you hear is the medics cussing about not being able to get a good reading, would you be wondering if they had a Class A product on board? On another point, the Big Three American auto makers have their own industry standards as they are exempted by the FCC. So in order to keep that exemption and not being regulated, the limits that the auto industry specifies are much lower than what the FCC uses. Remember way back when resistor spark plugs came out? Why? Because the FCC was getting off their butts and starting to protect the spectrum license holders like the AM radio stations, which were being interfered with by the old spark plugs. The auto industry responded with a quick will fix that right now. Then the resistive spark plug wires came out to add further protection and margin. Additionally, all the emergency vehicles are purpose built after market rigs and so are not regulated in the USA by either the auto manufacturer or the FCC. But should complaints arise at the FCC, there will be a reaction, since way back, the FCC changed from an "approvals" purposed organization, to an "enforcement" organization. And the FCC mandates that tho' shall not interfere, with spectrum holders, regardless of what your test report says. AU/NZ and EU run a whole different game for their regulations. The EU regulates the manufacturers and the after market folks as well. This popped up on a search for the E-mark. http://www.belemc.com/en/page/Default.asp?pageID=23 I have not looked into this in over 10 years. From: Carl Newton <[email protected]> To: [email protected] Sent: Saturday, January 30, 2016 11:19 AM Subject: Re: [PSES] [EXTERNAL] [PSES] AU CISPR 22 Class B Interpretation Bill, Laptops and tablets are Class B because they are commonly used within homes. A vehicular hard-mounted docking station installed within vehicles is not. I've worked for/with industrial control equipment companies for many years and their panel-mounted PCs are all Class A devices. It depends upon either where it's used or what type of AC mains connection is involved for most emissions standards. If this were an ISM device then CISPR 11 would clearly indicate that it's a Group 1 Class A device because it doesn't connect to the public AC mains. Thanks for your reply, Carl On Fri, 29 Jan 2016 15:23:54 -0500, Bill Stumpf <[email protected]> wrote: > Mr. Newton asked for opinions, so for what it's worth, here is mine. I > hope you will all excuse my rant. Many will interpret the "exclusions" > based on their viewpoint. Not being associated with a manufacturer, my > interpretation may be different than others. The FCC excludes devices > used exclusively in transportation vehicles from the technical > requirements of part 15, but not the general requirements "thou shall > not interfere". This FCC exemption also does not apply to devices that > could be used removed from a vehicle. An example would be a device that > connects to a vehicle USB or cigarette lighter power outlet. I have to > believe that the exemption exists because the FCC considers devices > installed "hard-wired" in transportation vehicles as covered by other > EMC requirements. Canada's exemption (ICES-003) specifically states > that it is only for devices that are factory installed in the vehicle. > Similarly then, for EU compliance I would look at this the same way and! > agree with Mr. McInturff. Laptop & tablet PC's are Class B. > Therefore as a Class B PC peripheral (auxiliary) device, it seems > logical to apply Class B to the docking station. > > Bill > > > > > -----Original Message----- > From: Jim Hulbert [mailto:[email protected]] > Sent: Friday, January 29, 2016 1:33 PM > To: [email protected] > Subject: Re: [PSES] [EXTERNAL] [PSES] AU CISPR 22 Class B Interpretation > > The FCC also exempts a digital device utilized exclusively in an > appliance, e.g., microwave oven, dishwasher, clothes dryer, air > conditioner (central or window), from the its Part 15 technical > requirements, so being rational doesn't always make sense. > > Jim Hulbert > > -----Original Message----- > From: Carl Newton [mailto:[email protected]] > Sent: Friday, January 29, 2016 2:04 PM > To: [email protected] > Subject: Re: [PSES] [EXTERNAL] [PSES] AU CISPR 22 Class B Interpretation > > Gary, > > With regard to auto EMC compliance, that is taken care of already. This > hardware is being subjected to AU/NZS CISPR 22 simply to satisfy AU ACMA > requirements. I appreciate your comments concerning the residential > zone, but I don't agree that simply because a vehicle may travel within > that zone that Class B is warranted. I would still expect the vehicle > to be no closer to homes than 10m in typical scenarios. > > From a pure EMC rationale point of view, consider that in the USA the > FCC exempts auto hardware from Part 15 rules. > > Thanks, > > Carl > > > On Fri, 29 Jan 2016 13:02:33 -0500, Gary McInturff > <[email protected]> wrote: > >> These vehicles travel between residential and commercial zones on a >> regular basis, so on that alone I would agree with the class B >> assessment, but I'm wondering if you don't have lots of other EMC >> issues to deal with - automotive immunity etc. >> >> The only time I've personally seen an exemption for Class A in a >> residential zone was for telecommunications equipment installed into a >> room or facility owned by a telecom company. Doesn't mean there aren't >> other exemptions it just means I am unaware of them. So I think you >> stuck with Class B IMHO >> >> -----Original Message----- >> From: Carl Newton [mailto:[email protected]] >> Sent: Friday, January 29, 2016 9:10 AM >> To: [email protected] >> Subject: [EXTERNAL] [PSES] AU CISPR 22 Class B Interpretation >> >> Group, >> >> My customer builds vehicular laptop and tablet docking stations >> intended for hard mounted use within emergency vehicles such as police >> and ambulance, as well as work trucks and forklifts. The vehicular >> power supply narrowly missed CISPR 22 radiated Class B limits. Then >> their AU Responsible Party told us they called the ACMA and they >> "insisted" this is a Class B device. I then sent my own request to >> ACMA and received the reply below. >> >> In my opinion the ACMA individual is clearly biased toward the Class B >> rating, but the fact that he leaves the door open to the Class A >> rating is enough proof for me that he agrees that it is a Class A >> device. >> However, my customer is looking for safety in numbers. The author >> raises a valid note of caution concerning receivers within vehicles, >> but these systems are already compliant with CISPR 25 and are widely >> used within North America and Europe with no interference problems so >> we're not concerned with that warning. >> >> I would appreciate it if some of you would review this information and >> provide your professional opinion as to whether vehicle mounted ITE >> qualifies as Class A or Class B: >> >> +++++++++++++++ >> >> Dear Mr Newton >> >> Clause 4.1 of AS/NZS CISPR 22 (which is identical to CISPR 22, Ed. 6.0 >> (2008)) includes the following; >> >> Class B ITE is intended primarily for use in the domestic environment >> and may include: >> >> - Personal computers and auxiliary equipment. >> >> Note: The domestic environment is an environment where the use of >> broadcast and television receivers may be expected within distances of >> 10 m of the apparatus concerned. >> >> Given that the class B limits apply to “personal computers” (which >> would also include “tablets”) it would seem logical that your mounting >> stations “for computers and tablets” (which I would think fall within >> the definition of “auxiliary equipment”) should comply with the same >> limits as the devices they are intended to hold. >> >> I would also think that, because police and ambulance vehicles will >> probably have a broadcast (AM/FM) receiver installed in them this >> would probably constitute a “domestic environment”. I would also >> question whether it would be prudent to have a device meeting the >> class A limits installed in a vehicle that relies heavily on two-way >> radiocommunications equipment where said device may interfere with the >> operation of this on-board radiocommunications equipment. >> >> Having said that, clause 4.2 of AS/NZS CISPR 22 includes the >> following; >> >> Class A ITE is a category of all other ITE which satisfies the class A >> ITE limits but not the class B ITE limits. Such equipment should not >> be restricted in its sale but the following warning shall be included >> in the instructions for use: >> >> Warning >> >> This is a class A product. In a domestic environment this product may >> cause radio interference in which case the user may be required to >> take adequate measures. >> >> It is up to you whether you wish to comply with the class A or the >> class B limits however, I would personally err on the side of caution >> – if an ambulance or a police car were unable use its >> radiocommunications equipment and it turned out it was due to >> interference from your device the legal ramifications could be costly. >> >> Regards >> >> XXXXXXXXXX XXXXXXXXX >> Technical Regulation Development Section Australian Communications & >> Media Authority >> >> ++++++++++++++++++++++ >> >> Thanks group, >> >> Carl >> >> >> > > > -- > Using Opera's mail client: http://www.opera.com/mail/ > > - > ---------------------------------------------------------------- > 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 <[email protected]> > > 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 <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> > > ________________________________ > > - > ---------------------------------------------------------------- > 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 <[email protected]> > > 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 <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> > > - > ---------------------------------------------------------------- > 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 <[email protected]> > > 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 <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher: <[email protected]> > David Heald: <[email protected]> -- Using Opera's mail client: http://www.opera.com/mail/ - ---------------------------------------------------------------- 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 <[email protected]> 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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]> - ---------------------------------------------------------------- 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 <[email protected]> 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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
