It apparently did it's job. But apparently it was given the wrong job. It is accused (by the manufacturer, of course) that someone entered the wrong amperage that it should do its job at. Unlike home circuit breakers which come in specific amperage levels (and vary from unit to unit by plus or minus 10 percent which is considered acceptable), these relay devices, which are a component in an overcurrent protection system, cannot be made at fixed amperage levels due to economics. They are quite expensive to replace with another just to tweak the settings due to changes made elsewhere in the power distribution network, and the number of different amperage values needed would be very large. They can be expensive also because either they directly connect to current transformers that have high open circuit voltage potential, or operate from digital sensors on the current transformers. They are also expected to have accurate at better than one percent.