Brent, On 27 Jun 2003 at 13:26, [email protected] wrote:
> > I got some weird "feedback" from one of our sales people in the Czech > republic. One of the local folks said they were concerned that a metal > cased piece of medical electrical equipment didn't have a separate ground > for when it was used on internal batteries. I'm an EMC guy so I was > wondering if any of the safety experts out there could tell me if this > makes any sense from a regulatory standpoint. > This may be a reference to a Potential Equilization Terminal. This is not mandated by IEC 60601-1, but may be required by local authorities or hospital policy, particularly for use in operating theatres or intensive care units. The terminals on different pieces of equipment are connected together to ensure that all earth potentials are the same in order to prevent possible current loops through the patient. Theoretically, it could also be necessary for battery powered equipment connected via a communication line to equipment in another room. If the patient were to accidently touch the metal enclosure, a current loop could be closed, if the connection caused the enclosure to be earthed at a potential different from that of other equipment to which the patient may be connected. Regards, Jon Griver http://www.601help.com The Medical Device Developers Guide to IEC 60601-1 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
