UL2089 covers appliance using the socket. There is no UL or CSA standard covering the socket itself, but there is SAE J563, which provided dimensions and limits the continuous current drawn through lighter sockets by appliances to 8Adc.
The intent is to protect the wiring in behind the lighter socket, because that wiring is based on an intermittent 10-15A load (how often do you light a cigarette?) and is therefore undersized for its overcurrent protection. In a sample of 7 or 8 cigarette lighter sockets and wiring harnesses that I pulled out of different makes of car in the mid 90's, I found wire sizes ranging from No. 16AWG to 22AWG, being protected by fuses ranging from 15 to 30A! In the world of continuous 12Vdc loads - aftermarket accessories like chargers for cell phones and laptops, in-your-car coffee makers and vacuum cleaners, etc - we need to know what continuous load the lighter socket and its harness can sustain. The SAE pegs this at 8A and UL and CSA are enforcing that limit, both in what they will allow a 12Vdc appliance to draw, and in requiring a max. 8A fuse in the lighter plug. Recognizing the limitations on lighter sockets, the automotive industry has come up with the "power point": a cylindrical connector based on the cigarette lighter socket but designed, fused, wired, and rated for continuous loads and lacking the bimetal fingers that release the lighter plug when it's hot. These are usually rated for 15-20Adc continuous, allowing designers to be free of the 8A limit. In theory. However, since the male plugs on 12Vdc automotive appliances will fit both the true lighter socket and these newer power points, UL and CSA will not back down (nor should they) from the 8A limit for a 12Vdc appliance equipped with a male plug that fits a lighter socket. They also will not accept a marking such as "Use only with power points, not with lighter sockets" because too many cars only have lighter sockets. Not sure you're trying to do anything with that kind of power level, but you should be aware of the limitations. Regards, Jim Eichner, P.Eng. Manager, Engineering Services Xantrex Technology Inc. e-mail: [email protected] web: www.xantrex.com Any opinions expressed are those of my invisible friend, who really exists. Honest. No really. Confidentiality Notice: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. -----Original Message----- From: Ron Baugh [mailto:[email protected]] Sent: Wednesday, September 18, 2002 3:41 AM To: 'Charles Blackham'; '[email protected]' Subject: RE: Current from Car 12V cigarette lighter socket Yes Charles it's UL 2089 "Vehicle Battery Adapters." I also have a unit (ITE Listed) that will operate from a auto battery and I have to make sure that all my 12V devices meets this standard. Ron Baugh VeriFone, Inc. -----Original Message----- From: Charles Blackham [SMTP:[email protected]] Sent: Wednesday, September 18, 2002 2:07 AM To: '[email protected]' Subject: Current from Car 12V cigarette lighter socket Some of our equipment runs off 12Vdc. Typically this is provided by a UL Listed ac/dc power supply that meets the Limited Power Source requirement of IEC60950. We wish to be able to power this from the 12V "cigarette lighter" socket in a car: Is there a standard that covers the output of 12V sockets in cars? Do they have to meet something similar to the Limited Power Source requirements of IEC60950? regards Charlie Blackham Senior Approvals Engineer Airspan Communications Ltd. ------------------------------------------- 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] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" ------------------------------------------- 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] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
