How low is 'low'? The simplest way is to make it a Limited Current Source then the relay is not a safety critical component (and redundant) can be purely functional and the operator will not feel any pain if it fails.
Best regards Gregg -----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of [email protected] Sent: Tuesday, December 10, 2002 3:34 PM To: [email protected] Subject: High Voltage Relay HELP!!! Happy Holidays Group, Let me set the scene for you: We have a piece of laboratory equipment that has a 10,000 volt low current power supply that puts a high potential onto a small metal sample as it is being tested. When the operator opens a door to remove the sample we have to turn off the high voltage to protect the operator. We have been looking for a High Voltage Relay to do the job without luck. We have found several that are rated for 10,000 volts, but the creepage and clearance spacing between the pins don't seem to match what the IEC61010-1:2001 standard says. If I am reading the standard correctly, the creepage is the big problem. Table 7 calls for a spacing of 40mm on pc cards pollution degree 1. This seems like a lot. The clearance would be 30.3mm - 31.6mm according to Table 5. We have one relay that is rated 10,000 volts, but it only has 23mm between the contact and the coil pins. How can this be? Am I looking at something wrong here? I can't find any high voltage relays with any kind of agency approvals. 1. Am I figuring out the creepage distance correctly or am I missing something? 2. If I do have to meet the spacings listed above, does anyone know of a good source for a compliant relay? 3. Anyone have tips and suggestions how to minimize spacings in high voltage circuits? Thanks to all. Brian Kunde LECO Corp. ------------------------------------------- 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"
