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Vox Power Limited | Unit 2, Red Cow Interchange Estate, Ballymount, Dublin 22, D22 Y8H2, Ireland | T +353 1 4591161 |
DOC-MN-008-03, VCCS300 User Manual
Reliability
The VCCS300 series has undergone extensive testing, including HALT and Environmental testing. Reliability data is collected on an ongoing basis. Please contact Vox
Power or your distributor for the most up to date reliability data.
The reliability data quoted in the datasheets are the calculated
failures per million hours (FPMH) using the Telcordia SR-332, issue 2 standard. The procedure defined
in SR-332 allows several different techniques to be used for calculating MTBF and when evaluating competing MTBF figures it is important that only the same
techniques are compared.
The quoted VCCS300 reliability figures use Method I Case 3, Ground, Fixed, controlled which specifies an ambient temperature of 30°C and an upper confidence level
of 90%. It is also assumed that the product is operated at 100% duty cycle, has an input voltage of 120V
RMS
, an output power of 300W and that the baseplate
temperature is the same as the ambient temperature.
The variation in FPMH is shown in the graph and table below.
Ambient Temperature
0
10
20
30
40
50
60
70
80
Failure Rate (FPMH)
0.46144630
0.613015302
0.815511105
1.0879098
1.45771725
1.96498947
2.66813507 3.65047088
5.0317409
MTBF (Hrs)
2167099.35
1631280.64
1226224.87
919193.78
686004.089
508908.57
374793.61
273937.26
198738.37
0
1
2
3
4
5
6
0
10
20
30
40
50
60
70
80
FP
M
H
Ambient Temperature (°C)
FPMH Vs Temperature
