think I am all set Chris, we are a final end user as you noted, thus havnet been subjected to fault hipot tests. as our internal temps are low, thus not warranting any more hipot tests.. thnak you for your clear reply on this. regards. Richard.
Richard A. Stone Excel Switching Corporation Compliance 75 Perseverance Way Hyannis, MA. 02601 508 862 3311 ph. 508 862 3020 fax This email message and any attachments to it contain confidential information that is intended only for the person or entity to which it is addressed. Any review, retransmission, dissemination, printing, or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please delete it or inform the sender. From: Chris Maxwell [mailto:[email protected]] Sent: Tuesday, February 10, 2004 10:08 AM To: Stone, Richard; Chris Wells; emc-pstc Subject: RE: IEC61010-1 multiple Overvoltage catagories in one circuit??? Richard, (answering message below) Most safety testing is by inspection of PCB layout, component specs and component ratings. For instance, if you use an approved power supply, the lab usually won't pull any single fault hi-pot tests on your unit. They'll probably be satisfied with performing a hi-pot test on the complete unit. You can rest assured that the manufacturer of your power supply probably suffered through numerous single fault hi-pot tests. As such, they won't be repeated on your design. However, if there is any doubt, the lab will produce a single fault and test the circuit for a hazardous condition. This is especially true if you design your own power supply, as we have done a few times. Part of this testing may be a hi-pot test. Furthermore, a design may have to pass a hi-pot test after going through the "blocked fan" single faults that you mention; perhaps only to verify that the elevated temperatures didn't compromise any insulation in the unit. This usually isn't the case; since most blocked fan tests don't cause temperature rises sufficient to exceed the temperature ratings of most insulation. After saying all of that; I have to qualify that it's just my opinion based upon my own experience and my now failing memory (I cycle through all three of my girls' names just to get one). Since I'm a safety lab "client", I'll defer the verification of my statements to someone who actually works at a safety lab. Anybody want to help Richard on this one? Chris Maxwell Design Engineer Nettest -----Original Message----- From: Stone, Richard [mailto:[email protected]] Sent: Tuesday, February 10, 2004 9:40 AM To: Chris Maxwell; Chris Wells; emc-pstc Subject: RE: IEC61010-1 multiple Overvoltage catagories in one circuit??? Chris, for #1 below, are you stating that for a hipot test the NRTL can do a single fault test, remove a part or anything else, being the single fault, then performing a hipot? I dont agree with this logic, please educate me if this is the case. Hipot should be done as a complete unit, intact. with No faults.....willing to learn from this forum.. Temp test is with one fault for heating purposes. hipot? thank you, Richard... Richard A. Stone Excel Switching Corporation Compliance 75 Perseverance Way Hyannis, MA. 02601 508 862 3311 ph. 508 862 3020 fax
