ČSN EN 16603-20-20

The target applications covered by this standard are all missions traditionally provided with power distribution and protection by LCLs/RLCLs (science, earth observation, navigation) with exclusion of applications for which the power distribution and protection is provided by fuses (e.g. most of the GEO telecom satellites). The present standard applies to power distribution by LCLs/RLCLs for power systems, and in general for satellites, required to be Single Point Failure Free. The present standard document applies exclusively to the main bus power distribution by LCLs/RLCLs to external satellite loads. A particular case of LCLs (Heater LCLs, or HLCLs) is also treated. The HLCLs are the protections elements of the power distribution to the thermal heaters in a spacecraft. Internal power system protections of LCLs/RLCLs are not covered. Paralleling of LCLs to increase power supply line reliability is not covered by the present standard, since this choice does not appreciably change the reliability of the overall function (i.e. LCL plus load). In fact, a typical reliability figure of the LCL (limited to the loss of its switch-on capability) is 20 FIT or less. If the load to be connected to the LCL line has a substantial higher failure rate than this, it is not necessary to duplicate the LCL to supply that load. This standard may be tailored for the specific characteristic and constrains of a space project in conformance with ECSS-S-ST-00.