chimp1
Member
- Location
- Palm Bay, FL US
When a panel is fed through a 3 phase breaker and one of the phases is higher than the rated current does the breaker trip.
3 Phase Breaker
- Thread starter chimp1
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All of your questions appear to be homework or study questions, is this the case?
Roger
Common breakers are "inverse time" rather than "instantaneous trip" type. They will trip on overcurrent, but how long and if it in fact does varies with the amount of time and level of overcurrent. Google "breaker time curves".
chimp1
Member
- Location
- Palm Bay, FL US
3 Phase Breaker
No, these are not homework questions.
No, these are not homework questions.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Wow, this is the first time you have replied to anyone. I was beginning to think you only wanted answers.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Each pole of a breaker has its own current sensing device, so each one, or rather any one, can initialed a trip by releasing the trip mechanism. All poles will open even if only one caused the trip. In fact, you could say that it is ALWAYS only one that causes the trip, because it is virtually impossible for more than one pole to carry the absolute exact same amount of current.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Not to mention that it is impossible to make all the trip points precisely equal.
So even on a phase-to-phase load/fault, one phase's trip mechanism will fire first, but all the poles should open simultaneously.
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