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Having a doubt in breaker and cable selection

  1. Sep 13, 2014 #1
    i have got a 150A breakerMCCB and the cable connected is 95sqmm and load current is 135A
    is this correct or any changes is to be made?
    what will happen if the supply is given from 420v 3phase system
  2. jcsd
  3. Sep 13, 2014 #2
    You have to state:
    1) the conductor: copper, aluminum?
    2) insulation: PVC, XLPE?
    3) single-core or multi-core cable?
    4) in air at 40oC, in conduit, in underground [in duct?]
    5) if it is embedded in Earth what is Earth temperature and what is the thermal resistivity.
    6) how many other cables are in close vicinity?
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