Mark, Can't help with the specifics of your request. However, as a side note, I once had a problem with an ultrasonic welder. It was located about 800 meters from our product in another building and was used in the diaper making process. The EMI from that welder caused our product to exhibit serious performance problems while operating. The only solution was to move our product to another area in the building, farther away from the source of the problem. Since the problem was located across the world from me, I was never able to determine if the problem was power line conducted or purely radiated. I never heard very much more after I gave my list of possible causes and solutions to the problem reported so, presumably, the problem was solved by relocation.
Scott [email protected] ECRM Incorporated Tewksbury, MA USA -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Tuesday, October 12, 1999 12:30 PM To: [email protected] Subject: EMI from nearby welding The query I'd like to put to the readers of this list is not exactly EMC related, but is close enough that I hope you'll forgive me asking. Can anyone give me an idea of the voltages likely to be induced in the unprotected input wiring of a process plant control system, when welding is carried out nearby? Or point me to a resource that may give me some help? The welding cables will be close (within a metre of the inputs to the control system, perhaps even touching the control system metal case). The welding transformer will be tens of metres away. The process plant control system is an old logic design based around 4000 series CMOS. The control system will not be energised when the welding is going on, so my main worry is induced voltages/currents blowing up the CMOS. Should I worry, or sleep happy? All advice gratefully received (except if someone tells me to throw away the control system and get something better protected, as that's not an option...) Regards, Mark -- Mark Hone Wellman CJB Limited Email: [email protected] Airport Service Road Tel: +44 (0)2392 629239 (Direct) Portsmouth, Hampshire Tel: +44 (0)2392 664911 PO3 5PG, ENGLAND Fax: +44 (0)2392 697864 --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators). --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
