Re: [PSES] Surface mount resistors failing short circuit

2014-11-17 Thread Charlie Blackham
Subject: Re: [PSES] Surface mount resistors failing short circuit In message 052386ecbaec46bb9a46af06a46b1...@sehste15d1be4.hs20.netmailto:052386ecbaec46bb9a46af06a46b1...@sehste15d1be4.hs20.net, dated Mon, 17 Nov 2014, Charlie Blackham char...@sulisconsultants.commailto:char...@sulisconsultants.com

Re: [PSES] Surface mount resistors failing short circuit

2014-11-17 Thread CR
On 11/17/2014 5:27 AM, John Woodgate wrote: In message 052386ecbaec46bb9a46af06a46b1...@sehste15d1be4.hs20.net, dated Mon, 17 Nov 2014, Charlie Blackham char...@sulisconsultants.com writes: The NRTL insist on short-circuiting the single 560R current limiting resistor and I am unable to

Re: [PSES] Surface mount resistors failing short circuit

2014-11-17 Thread John Woodgate
In message c0b6a3945850415a954ab740399ae...@sehste15d1be4.hs20.net, dated Mon, 17 Nov 2014, Charlie Blackham char...@sulisconsultants.com writes: The equipment, circuit diagrams and component specifications are examined to determine those fault conditions that might reasonably be expected to

Re: [PSES] Surface mount resistors failing short circuit

2014-11-17 Thread Greg McClure
Charlie, The spacing between the pads where the SMT resistor is mounted may be so small that the resistor failure mode doesn't matter. The creepage distance itself may require consideration of a short between the pads as a valid single fault condition.. Gregory H. McClure Lexmark Product Safety

Re: [PSES] Surface mount resistors failing short circuit

2014-11-17 Thread jral...@productsafetyinc.com
Did you do the test to see what happens? Maybe the battery drains before there's a risk of fire?? On Nov 17, 2014, at 7:22 AM, Greg McClure gmccl...@lexmark.commailto:gmccl...@lexmark.com wrote: Charlie, The spacing between the pads where the SMT resistor is mounted may be so small that

Re: [PSES] Surface mount resistors failing short circuit

2014-11-17 Thread Bill Owsley
Yes sir they can fail to a short circuit.  And some do it gradually so you can watch it happen.We were amazed and watched it over and over, having never seen anything like it before.It started with brief pulses of over voltage in an AC application, No DC to continue the brief arc.  After the

Re: [PSES] Surface mount resistors failing short circuit

2014-11-17 Thread Richard Nute
Hello Charlie: I suggest you go ahead with the short-circuit test. I can’t imagine a coin-cell battery failing the criteria specified in 60950-1. These tests shall not result in any of the following: − chemical leaks caused by cracking, rupturing or bursting of the battery