I’m no electrical engineer nor electrician and my job requires a lot of maintenance activities at a plant and I’ve searched and ask engineers but I can’t grasp what they really mean in simple terms.
In: Engineering
In casual usage, they are interchanged as though they mean the same thing. But as another poster points out, “faulting” implies something has gone wrong with the system while “tripping” is the protective devices response to the fault.
Faults are things that are not supposed to happen, like a hot wire conducting to Ground. Trips are protection system reactions to what they determine as a fault. Circuit breakers trip when too much current runs through them and GFCIs trip when the current out the hot wire doesn’t match the current back on the neutral wire.
The idea, in a safe system design, is that faults cause trips. Protection systems are supposed to detect faults and safe the system. It is possible to overdo protection, so that not all trips are the result of a fault. For example, a high current motor can surge when the coils are powering up and trip an incorrectly chosen GFCI. A breaker that’s worn can trip at less than the specified current, annoying the hell out of maintenance electricians.
A fault is something that has gone wrong. A trip is something that shuts things down before a fault happens based on sensing that a fault is about to occur. The trip protects the system from damage that would be caused by the fault.
Fault is an actual occurrence of failure. Trip is a mechanical response to a (supposed) failure condition. You will hear the term “Nuisance Trip”, meaning a device meant to mitigate damage in a fault condition has responded as if a fault exists when none does, because it itself is faulty or there is some “slop” between what’s detected as a fault and what actually is one.
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