SR-332 MIL-HDBK-217F MIL217F - Datasheet Archive

Section 7 - MTBF MTBF's have been calculated using Telcordia SR-332 and MIL-HDBK-217F Ground benign. The modular nature of the

Vega Customer Applications Manual Section 7 - MTBF MTBF's have been calculated using Telcordia SR-332 SR-332 and MIL-HDBK-217F MIL-HDBK-217F Ground benign. The modular nature of the product makes it difficult to determine the MTBF for every combination of output voltages and load, the numbers given are therefore typical. The tables below give the failure rate per million hours (FPMH) for each of the assembly types at different ambient temperatures. Telcordia SR-332 SR-332: Description Converter Single Slot Module (B,C,L) One and a half or two slot module (D, E, F) Twin Module (H) Secondary Option Primary Option (100mA / 300mA) Primary Option (1A) 0°C 0.50 0.12 0.2 0.21 0.10 0.05 0.15 30°C 1.18 0.35 0.47 0.57 0.28 0.22 0.35 40°C 1.59 0.54 0.64 0.85 0.41 0.42 0.51 50°C 2.16 0.87 0.90 1.31 0.61 0.81 0.77 MIL-HDBK-217F MIL-HDBK-217F: Description Converter Single Slot Module (B,C,L) One and a half or two slot module (D, E, F) Twin Module (H) Secondary Option Primary Option (100mA / 300mA) Primary Option (1A) 0°C 5.17 1.19 1.36 1.88 0.22 1.37 1.87 30°C 7.10 1.51 1.75 2.34 0.70 2.37 4.23 40°C 8.72 1.82 2.14 2.80 1.35 3.35 5.55 50°C 10.00 2.13 2.52 3.23 2.06 4.25 7.26 To Calculate the MTBF for a given configuration, sum the FPMH figures for each individual assembly/module to produce a total FPMH. The MTBF is then simply given by 1 /FPMH and is expressed in millions of hours. Examples Vega 650 B1L_N E5H H2/1H MTBF at 40°C Description 650W Converter B Module N Option E Module H Module Total MTBF MIL-HDBK-217F MIL-HDBK-217F 8.72 1.82 1.35 2.14 2.80 16.83 59,417 hrs Telcordia SR-332 SR-332 1.59 0.54 0.41 0.64 0.85 4.03 248,139 hrs MIL-HDBK-217F MIL-HDBK-217F 7.10 1.51 8.61 116,144 hrs Telcordia SR-332 SR-332 1.18 0.35 1.53 653,594 hrs Vega 450 C3 at 30°C Description 450W Converter C Module Total MTBF Note, the above calculations do not include the cooling fan. MIL217F MIL217F and Telcordia model the fan as a motor and as such, if included, the figure generated would dominate the overall MTBF figure. To include the fan then add the FPMH of the fan to the total FPMH: At 30C failure rate = 4.09 At 50C failure rate = 7.51 69211 iss 4 Page 1 of 1