A redundant fault protection architecture for a DC electrical system with a hybrid relay sensing current on a DC rail as primary protection, and a pyrofuse, either self-triggering or externally triggered, as secondary protection. The pyrofuse is set to trigger after a delay to enable the hybrid relay to clear the fault (overcurrent). If the hybrid relay fails to clear the fault within a certain time duration, the pyrofuse subsequently is triggered and clears the fault.

A redundant fault protection architecture for a DC electrical system with a hybrid relay sensing current on a DC rail as primary protection, and a pyrofuse, either self-triggering or externally triggered, as secondary protection. The pyrofuse is set to trigger after a delay to enable the hybrid relay to clear the fault (overcurrent). If the hybrid relay fails to clear the fault within a certain time duration, the pyrofuse subsequently is triggered and clears the fault.