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Working out the overload on this motor fan unit?

Discussion in 'Electrics UK' started by markymark2406, 23 Jul 2019.

  1. markymark2406

    markymark2406

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    Just trying to work out the overload setting for this motor, I calculate by the information on the plate of the motor that it should be set to 0.53A is this correct.
    Just a confirmation ?
     

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  2. conny

    conny

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    The full load current is 0.94A This is what the running current will be when the unit is under full load. If you set the trip to 0.53 you may have nuisance trips once the unit starts working. The FLC is the maximum safe working current that the unit is designed to run at when fully loaded so unless you know what load you will be running it under 0.53 is too low. Inrush currents above 0.94A will have no adverse effect on the windings and will drop once the unit is up to speed. Motor overloads should be no more than 115%-125% of the nameplate current rating. The clue is in the word 'overload'.
    Based on this I would suggest you set your trip to no more than 1.4A
     
  3. Echo the husky

    Echo the husky

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    You would also need to check with the overload manufacturers instructions, many new ones say set the overload to FLC vaule, many older ones say set it to FLC+10%
     
  4. AdrianUK

    AdrianUK

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    Why do you feel it should be 0.53A?

    Have you divided by root(3) thinking this somehow gets you the phase current?

    The FLC current quoted on the motor is the current in EACH phase, not some kind of total current.
     
  5. mikeyd

    mikeyd

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    Seriously? Not sure why it should have an overload but set it 1 (plus a tweak) Amps and move on.
     
  6. AdrianUK

    AdrianUK

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    He can't! That O/L unit is 0.4 to 0.63A .... its the wrong one for that motor!
     
  7. Simon35

    Simon35

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    Set it to motor FLC, job done.
     
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