1 phase sorted - Why the other 2 phase is OK ?

Discussion in 'General Electronics Chat' started by Mentis, Jan 21, 2011.

  1. Mentis

    Thread Starter New Member

    Oct 27, 2006
    Hi everybody,
    Recently i experience a interesting problem, here it goes:
    I have a 3 phase load , each phase protected by a Circuit Breaker.
    Due to maintenance lapses, 1 of the phase is shorted. melting the connector pin in the process. The associated circuit breaker "extended" which is normal for that to happen. But the 2 remaining load's circuit breaker did not "extent"
    the interesting thing is that pins for the remaining 2 phases also showed signs of melting. I need to know why ?
  2. debjit625

    Well-Known Member

    Apr 17, 2010
    May be this is the reason not sure.....

    Their are two types of 3 phase power configuration Y or star type and another is Delta ,in delta type each load is connected to each phase and having a greater phase current compared to star type.Now if any phase is open in a delta connection (as circuit breaker tripped) the other two will continue without problem but if the any source phase winding opens then their will be a increase in the phase current.

    May be this increase cause the other two breaker to show signs of melting.