At 17:14 -0500 7/5/03, Eric Penne wrote: >I've been doing some research on getting a battery charger tested for >EMC and safety in the EU. > >The battery chargers range in outputs for 48V DC to 144V DC battery packs. >The output max currents range from 10A to 35A with 230V 50Hz input. I >started with the LVD which pointed me to 60335-1 and 60335-2-29 for >battery chargers. > >I have an older 60335-2-29:1991 that says the maximum output OC voltage of >the battery charger is 42.5 Volts. This means that I need to find another >standard to cover the safety for the chargers.
No, not necessarily. It may mean that you can't make a battery charger for household use which exceeds this voltage without violating the ESR's of the LVD. So far as I am aware there is no case law to back this up, but if the LVD standard for battery chargers places a limit on the battery voltage, it's probably because the BOGSAT [1] who wrote the standard considered this was the maximum safe voltage in the context of the scope of the standard and the other measures which it requires for the safety of the equipment. If you read the standard thoroughly you will find that this is because this voltage is the upper limit for SELV, and the standard assumes that battery chargers for household use will generally be used with batteries which have accessible contacts. Ergo, for consistency, the output has to be SELV and cannot exceed the SELV voltage limit. If you are making a charger for a domestic or other non-industrial application, you may have to accept that the battery terminal voltage cannot exceed 42.5V. Sorry, but it's back to the drawing board with your battery design. If you are making a charger for non-domestic battery applications, you can still use 60335-2-29, but since your design cannot meet the SELV limit for terminal voltage, you need to find an alternative method of protection which is as good. It looks like you will have to ensure that the user of the batteries (and the charger) are always protected from contact with the terminals by double insulation, including the creepage and clearance distances. For a definition of double insulation, see the relevant parts of EN 60335 and take into account the actual terminal voltage you are using when determining breakdown voltages and creepage and clearance distances, etc. You might be able to use this solution to make a charger for domestic applications as well. The whole point about the LVD is that you, the manufacturer, have to make your own mind up about how you are going to apply the standards and ensure your products are safe. Unless, of course, you want to pay someone else to make your mind up for you. That's what electrical safety consultants are for, and we all charge very reasonable rates! >I can't find anything else >that would cover these chargers. Where do I need to look to find safety >testing information for these chargers? You've already got it, you're just not using it properly! regards Nick. [1] - Bunch Of Guys Sat Around Talking This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
