Location: Breaker Failures

Where a circuit breaker will fail...

A circuit breaker has limitations as it is a mechanical device. Unfortunately, physics AND electronics must both be associated with best practices regarding Breakers. A breaker literally throws a switch internally to interrupt the flow of electricity when it "BREAKS". Below are some examples of how a breaker can literally fail, allowing higher amperages than rated:
  1. Breaker can be disrupted by G-Forces
    as seen in aircraft, holding the breaker open.

  2. Breaker can be disrupted by Cold
    as seen in outdoor installs, the breaker has to see current well in excess of rating to open.

  3. Breakers can be Disupted by Heat
    as seen in desert installs. A derating of 70% or higher is required to avoid breaker interruption under moderate heat. Under extreme heat, breakers are not applicable.

  4. Breaker can be disrupted by Liquids:
    as seen in outdoor installs, the breaker remain dry to "sense" current. Water creates a bypass, allowing well in excess of rating.

  5. Breakers can be disrupted by Age
    every time a breaker opens, there is a small amount of arcing between the contacts as they separate. This arcing scars the electrode, making it much less conductive. Over time, this leads to failure.
Fuses on the other hand, being inert, are able to go into places where a breaker simply can not. Please click here to see more about fuses.

Remember, be safe. Breakers do not work under all circumstances, electricity does funny things under very high current conditions, very high altitudes, underwater, in exceptionally dry conditions and many more. Therefore there are limits to where a breaker can operate properly.

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