Power Supply PS1000-D2-24.40.RM
Lifetime Expectancy and MTBF
20
21
-1
1
13
7
Lifetime Expectancy and MTBF
The redundancy module has two input channels which are completely independent
from each other. Each control circuit, auxiliary voltage source, or other circuitry in the module
are designed separately for each input. The dual input redundancy module can be considered
as two single redundancy modules combined together in one housing. The only common point
is the circuit trace that ties the two separate circuits together at the output.
The MTBF figures below are for the entire dual input module. If the MTBF number of only
one path is needed, simply double the value from the table.
Input / output current conditions
Input: 2x10A
Output: 20A
Input: 2x20A
Output: 40A
Lifetime expectancy
1
672 000h
1
255 000h
1
at 24V and 40°C
1 900 000h
1
720 000h
1
at 24V and 25°C
MTBF
2
SN 29500, IEC 61709
7 234 000h
4 533 000h
at 24V and 40°C
12 445 000h
8 218 000h
at 24V and 25°C
MTBF
2
MIL HDBK 217F
325 000h
294 000h
Ground Fixed GF40 (24V and 40°C)
438 000h
392 000h
Ground Fixed GF25 (24V and 25°C)
1 588 000h
1 457 000h
Ground Benign GB40 (24V and 40°C)
2 159 000h
1 964 000h
Ground Benign GB25 (24V and 25°C)
1
The
Lifetime expectancy
shown in the table indicates the minimum operating hours (service life) and is determined by the lifetime
expectancy of the built-in electrolytic capacitors. Lifetime expectancy is specified in operational hours and is calculated according
to the capacitor’s manufacturer specification. The manufacturer of the electrolytic capacitors only guarantees a maximum life
of up to 15 years (131 400h). Any number exceeding this value is a calculated theoretical lifetime which can be used to compare
devices.
2
MTBF
stands for
M
ean
T
ime
B
etween
F
ailure, which is calculated according to statistical device failures, and indicates reliability
of a device. It is the statistical representation of the likelihood of a unit to fail and does not necessarily represent the life of a product.
The MTBF figure is a statistical representation of the likelihood of a device to fail. A MTBF figure of e.g. 1 000 000h means that
statistically one unit will fail every 100 hours if 10 000 units are installed in the field. However, it can not be determined if the failed unit
has been running for 50 000h or only for 100h.
