Forum: Reliability & Maintainability Questions and AnswersTopic: Reliability & Maintainability Questions and AnswersTopic Posted by: Reliability & Maintainability Forum (src_forum@alionscience.com )Organization: System Reliability Center Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998
Original Message:Posted by: AnanyaDate posted: Tue Oct 4 10:29:58 US/Eastern 2005 Subject: Why failure rate of a capacitor is higher for non-operating vs operating condition Message: Hi, In RAC Prism, if you calculate the failure rate of a system which contains 1 capacitor; at (negative) -10C, 100% duty cycle, GS operating environment, Military Ground operating profile, relative humidity 40, vibration level 0, cycling rate 1, year of manufacture 2005, capacitance 0.1uF, operating volatge 0.001V and rated voltage 50V; you get 0.001131 fpmh. This is the "operating condition". If you calculate the failure rate of a system which contains 1 capacitor; at (negative) -10C, 0% duty cycle, GS operating environment, Military Ground operating profile, relative humidity 40, vibration level 0, cycling rate 0, year of manufacture 2005, capacitance 0.1uF, operating volatge 0.001V and rated voltage 50V; you get 0.002333 fpmh. This is the "non-operating condition", with 0% duty cycle and 0 cycling rate. Why is the failure rate under non-operating (dormant) condition higher than the failure rate under the operating condition? Shouldn't it be the other way around? Thanks for your help in advance. |