breaker size calculation for the freezer according to NEC

Discussion in 'General Electronics Chat' started by tahir mehmood, Sep 14, 2015.

  1. tahir mehmood

    Thread Starter New Member

    Jun 28, 2013
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    we have a special type Freezer, it is single phase 240v, 60 hz, the full load amperes are 10A, I need to calculate the breaker size for it according to NEC.
     
  2. tahir mehmood

    Thread Starter New Member

    Jun 28, 2013
    16
    0
    My calculations are:

    FLA * 1.75
    10*1.75=17.5 240.6(A) and 440.22(A) as per NEC.


    Am i doing the correct calculation?
     
  3. #12

    Expert

    Nov 30, 2010
    16,261
    6,768
    It is difficult to know the electrical code when we can't tell what country you are in.
     
  4. Johann

    Senior Member

    Nov 27, 2006
    190
    30
    Where I live, the breaker in the distribution board protects the wiring of the installation and not the appliance plugged into a socket. It should have its own integral protection.
     
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  5. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,450
    1,066
    Same in the USA and CAN; likely also in the EU.

    Breakers at the distribution panel are chosen based on the wire gauge of the branch circuit; not on the individual appliance...
     
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  6. KeepItSimpleStupid

    Well-Known Member

    Mar 4, 2014
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    It's not a continuous load, but you have not specified distance to the load. 500 or 30' could make a difference.
    So the breaker would be the next size up after doing the voltage drop calculations. I believe you want less than 3%.
    If it were continuous - on or more than 3 hours at a time, I believe, sizing would start at 125% or (1/0.8).
     
  7. Johann

    Senior Member

    Nov 27, 2006
    190
    30
    These calculations should be done during the design of the electrical installation. This will ensure correct sizing of the wire gauge of the branch circuit. The size of the breaker will then relate to the current-carrying capacity of the particular gauge of wire used, but as was mentioned before, this has no relevance to the needs of the appliance which should have its own integral overload cut-out or other form of overload protection.
     
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