Pennwood Wrong Wattage for Pennwood numechron motor

Discussion in 'Electric Horology' started by 78Rus, Dec 8, 2011.

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  1. 78Rus

    78Rus New Member

    Dec 5, 2011
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    Saint-Petersburg
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    Hi! I have two motors (pennwood numechron) for desktop clock. Wattage indicated as 3,7 W. But when connect ammeter is obtained 50mA, which corresponds to 55W. Why so? Thanks!
     

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  2. praezis

    praezis Registered User

    Feb 11, 2008
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    Germany
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    ...because 120V x 50mA gives 6W, no 55W :confused:
    ...because with inductive loads there is a phase shift between AC voltage and current, and then V x A is different from Watt.
    ...because a running motor generates his EMF voltage which is subtracted from his supply voltage.

    Regards,
    Frank
     

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