Comments by "SeanBZA" (@SeanBZA) on "The Engineering Mindset" channel.

  1. US breakers are specified slightly differently to EU and rest of the planet. There that rip current, say 10A, is a current it will trip at within a certain time, and normal operation you derate to around 70% for continuous loads. Short peaks for start up are allowed, but long term, over say an hour, will trip them at the face plate current. Unlike the DIN and others, which are rated to not trip at the rated current. Incidentally a hot breaker will trip at a lower overload, at least till it cools down, and a breaker in a board with adjacent hot running breakers will also trip closer to the minimum of the curve. conversely a breaker outside, in very cold weather, might not trip at all other than on the short circuit current, which is why you often will find the feed to a house is provided by a series connection of a fuse and a breaker, as the fuse, normally at the supplier tap off, will be guaranteed to always fail after a period of moderate overload, while the breaker is possible to have fail shorted.
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