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Over load relay

  1. Mar 26, 2014 #1
    Please See the drawing and Advise......

    Attached Files:

  2. jcsd
  3. Mar 26, 2014 #2
    Overload - is just that - too much load on the motor, this is typically a long time ( relative to Short circuit issues) the OL Relay is configured for this case,, e.g. 150% of full load for 60 Seconds - etc.

    A short circuit - is a fault, and the MCB is set up to protect for these cases, for example 5 to 10 x the Full load current, and this typically will trip in short ( 0.1 to 0.5 Sec after the Current is detected) or Instantaneous (as soon as the current is detected) -

    The two device are protection for different types of problems.

    Google Coordinated Motor Protection - that will probably be helpful.
  4. Mar 28, 2014 #3
  5. Mar 28, 2014 #4


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    Staff: Mentor

    Thread locked.

    ismat143 -- please check your PMs.
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