Don: I’m not a safety expert and I don’t know the nature of your cells but I can tell you from an electrical standpoint, that there are many components, such as batteries, where it is not a good idea to have combinations of parallel and series cells. This is because there is no guarantee the current will divide equally and one cell may receive excess current. Again in the case of batteries one cell can over heat and possibly explode.
Fred Townsend _____ From: [email protected] [mailto:[email protected]] On Behalf Of MacArthur, Don Sent: Monday, August 13, 2007 12:02 PM To: [email protected] Subject: ATEX Requirement for Cell Connection EN 60079-15: 2005 which is titled Electrical apparatus for explosive gas atmospheres – Part 15: Construction, test and marking of type of protection “n” electrical apparatus, and other hazardous locations standards have cell connection requirements which are as follows: “Cells shall be connected in series except for the specific case where two cells are connected in parallel with no further cells connected in series.” My questions to the group are: 1. Why is the above statement a requirement? Worded another way… 2. What is the safety issue when cells are connected in series with some in parallel when the cells are used in an explosive gas atmosphere? I’ve asked around various safety agencies and have not received a response let alone any response that makes sense. Kind Regards, Don Don MacArthur Compliance Engineer General Dynamics - Itronix Corporation 12825 E. Mirabeau Parkway Spokane Valley, WA 99216 ph: 509-742-1342 fax: 509-742-1672 email address: <mailto:[email protected]> [email protected] “This email message is for the sole use of the intended recipients and may contain GDC4S confidential or privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not an intended recipient, please contact the sender by reply email and destroy all copies of the original message.” ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ - ---------------------------------------------------------------- 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 [email protected] 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 [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - ---------------------------------------------------------------- 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 [email protected] 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 [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
