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All, <br>
<br>
MTBF is and has been a valid measurement in the electric/electronics<br>
manufacturing world for many years, used by all manufacturers. I have not<br>
looked, but I suspect all inverter manufacturers could give an equivalent<br>
number for their products.<br>
<br>
It is not something new or whiz-bang.<br>
<br>
However it remains a purely theoretical method of quantifying a failure rate<br>
on a product that has few years of 'in-the-field' lifetime to back it up,<br>
and should not be confused with MTTR (mean time to replace), which also is a<br>
valid tool used for many years.<br>
<br>
Coming from a manufacturing field, I can verify that it is a time-consuming<br>
calculation with arms reaching into MIL-SPEC as well.<br>
<br>
-Glenn Burt <br>
<br>
-----Original Message-----<br>
From: <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a><br>
[mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>] On Behalf Of Marv Dargatz<br>
Sent: Thursday, March 26, 2009 1:38 PM<br>
To: RE-wrenches<br>
Subject: [RE-wrenches] MTBF<br>
<br>
All,<br>
<br>
Mean Time Between Failure (MTBF) is a statistical number that is based on<br>
failure rates of components in a piece of equipment, under specific<br>
operating conditions. Numerical analysis, with testing and historical data,<br>
results in this calculated number. MTBF can be applied to a number of real<br>
world mechanisms. For example, the MTBF of most solar modules is on the<br>
order of 600 years. The MTBF of an average American 30-something year old<br>
male is 900 years. Enphase will shortly be publishing a white paper that<br>
explains how MTBF ratings are determined and gives more details about the<br>
MTBF rating of our micro-inverter.<br>
<br>
If you would like, I'll post a notification on this list when the paper is<br>
available.<br>
<br>
See Ya!<br>
<br>
Marv<br>
Enphase Energy<br>
707 763-4784 x7016<br>
<br>
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