Comnet - Modular expansion base - card cage with dual PSU - rack-mountable

The design approach employed by ComNet for equipment mounted within the card cage rack unit (C1-CH) with modular power supply (C1PS), provides for the elimination of a single-point failure in the event of a major fault within any module located within the chassis rack. This is accomplished through the use of automatic electronic current limiting within each rack-mountable module, rather than providing the current limiting within the power supply unit which supports the power requirements for equipment located within the rack. In nearly all competing designs, a major fault within a module, located within the chassis rack, results in the power supply unit going into a current limiting condition, and as a result, all of the modules within the rack shut down. The rack design employed by ComNet eliminates this possibility, as only the faulty module shuts down, and the operation of the other modules within the rack continue unimpaired. This automatic current limiting feature is also self-resetting, should the fault or overload be of a temporary or intermittent condition. Furthermore, all modules located within the chassis rack are hot-swappable, so that it is not necessary to power-down the rack when removing or replacing modules.