I'll tell you this story and everyone will go aah-huh! I designed (patents pending 38 years ago) and developed a 200,000 volts DC paint spray system. I had the same very large steel net cage area on an isolated second floor with all the safety devices and static drains. After completion of the test the ritual was to slowly drain the charge and remove the hose from the test stanchions. Something went wrong (I can't believe it was sabotage), the hose was OK but the stanchions did not drain and became a giant charged capacitor. I came to (gives a new meaning to field of dreams) awhile later with a strong aversion to the smell of ozone. Dewey -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Inge Sent: Wednesday, July 08, 2009 1:49 PM To: [log in to unmask] Subject: Re: [TN] IPC High Voltage PCB Marking and Spacing I would like a more dramatic label : Warning! You are in Danger! If I saw that I would look around, take a few steps back and go to a safer place. Reminds me when I made some tests in a steel net cage with a 50,000 Volt transformer. Only label was a little sign on the door : Lock the door after you! Another peculiar memory. A engineer had built plexi box for testing TWTs. He had built in security switches so that the high voltage be broken if someone opened the door. One day, we found him on the floor, plexi box door open and security switches taped over. He survived. But high voltage can be fun too. When young, I had very thick rubber shoes. Put finger on 100 Meg resistor connected to red terminal, and charged myself to 20 kV (don't do that with a supply that can generate more than 10 mA !) and walked out in the corridor. Saw some of the others and used index finger, pointed close to the guy's nose and said 'you got something there, have you cut yourself? ' . Well, in one such case of practical joke, I had to run. My victim had a short fuse. And the revenge was not far off. One day, I sat down as usual at my lab bench, rolled the chair closer to the bench and ...SPRZZZT!... 20 kV directly into my leg. They had used a high voltage cable from the other room, connected it to the bench steel frame (standing on nylon feet) and ..you understand what of course. From fun to reality. It's necessary to respect the laws and use safety arrangements. Too many people die every year from current (not voltage). And many are electricians and other technical guys. To be in the game is not the same as being safe. Far from. We who use electrical equipments daily are presumptive victims more often than we think. I will end this little extra with a advice from my days working with dangerous boxes : one hand on screwdriver, the other in the pocket....means: keep and eye on your left hand when your right hand is in a working equipment. Has saved many lives. Inge ----- Original Message ----- From: "Phil Nutting" <[log in to unmask]> To: <[log in to unmask]> Sent: Wednesday, July 08, 2009 9:49 PM Subject: Re: [TN] IPC High Voltage PCB Marking and Spacing Toby, We use the creepage and clearance requirements as outlined in EN60601, EN601, IEC950, etc. For marking I use the European triangle with the lightning bolt/arrow. If wording is used I use the requirements of ANSI Z535.6 to determine the level of hazard presented by the high voltage; Is death or serious injury a credible possibility? If No, then use CAUTION If hazardous situation occurs, how likely is accident? If Possible, then use WARNING If accident occurs, how likely is death or serious injury? If Possible, then use WARNING If accident occurs, how likely is death or serious injury? If Almost Certain, then use DANGER The use of Danger versus Warning is a bit subjective. Take into consideration the voltage and current levels present in the hazard. I hope this helps, Phil Nutting Design for Manufacturing Engineer Kaiser Systems, Inc. 126 Sohier Road Beverly, MA 01915 voice: 978-922-9300 x1310 fax: 978-922-8374 e-mail: [log in to unmask] www.kaisersystems.com -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Toby Carrier Sent: Wednesday, July 08, 2009 3:20 PM To: [log in to unmask] Subject: [TN] IPC High Voltage PCB Marking and Spacing Hi All, Does anyone know of an IPC standard that states a requirement of high voltage spacing and marking? I know that UL requires spacing based on the voltage, but not for sure about IPC. Thanks for the help. Toby Engineering Technician --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- Note: All the information contained in this e-mail and its attachments is proprietary to Kaiser Systems, Inc. and it may not be reproduced without the prior written permission of sender. If you have received this email in error, please immediately return it to sender and delete the copy you received. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------