Technical data, application notes, wiring
PS9031-4820-0001
19
1.0
4.10
Lifetime expectancy
The lifetime expectancy shown in the table indicates the minimum number of operating hours (service life)
and is determined by the lifetime expectancy of the built-in electrolytic capacitors. The lifetime expectancy is
stated in operating hours and is calculated according to the specifications of the capacitor manufacturer. The
manufacturer of the electrolytic capacitors only guarantees a maximum life of up to 15 years (131,400h). Any
number exceeding this value represents a calculated theoretical service life which can be used to compare
devices.
Calculated lifetime expectancy
161,000h
Standby mode, 40 °C
457,000h
Standby mode, 25 °C
4.11
MTBF
MTBF stands for
M
ean
T
ime
B
etween
F
ailure, which is calculated from the statistical failure rate of the
components and indicates the reliability of a device. It is a statistical representation of the probability of
equipment failure and does not necessarily represent the service life of a product.
The MTBF number is a statistical representation of the probability of equipment failure. An MTBF number of
1,000,000h, for example, means that statistically, if there are 10,000 devices in use, one device will fail every
100 hours. However, it is not possible to say whether the failed device has been in operation for 50,000
hours or only 100 hours.
For these device types the MTTF value (
M
ean
T
ime
T
o
F
ailure) is identical to the MTBF value.
MTBF SN 29500,
IEC 61709
2,348,000h
Standby mode, 40 °C
4,231,000h
Standby mode, 25 °C
MTBF MIL HDBK
217F
405,000h
Standby mode, 40 °C, Ground Benign GB40
636,000h
Standby mode, 25 °C, Ground Benign GB25
134,000h
Standby mode, 40 °C, Ground Fixed GF40
198,000h
Standby mode, 25 °C Ground Fixed GF25
4.12
Functional wiring diagram
14: Functional wiring diagram
