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Estimating operating temperature of wire.

  1. Dec 21, 2013 #1
    Estimating operating temperature of solenoid winding.

    Greetings everyone,

    I am currently doing a design project on solenoids/electromagnets. What I need to specifically calculate is the operating temperature of the solenoid winding under operating conditions. The solenoid is within a metal casing with specified thermal properties and I have values of voltage, ambient temperature, coil resistance (at 25degrees), power, current and number of turns. Is it possible to estimate the temperature of the wire? I'm thinking that solving this requires the use of the heat equation in 1d and treating the winding as just a simple length of wire, but the fact that there is an ambient temperature also influencing the temperature of the winding confuses me greatly. Any help would be much appreciated.

    Last edited: Dec 21, 2013
  2. jcsd
  3. Dec 22, 2013 #2


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    Welcome to PF.

    The limiting coil temperature will be set by the durability of the coil insulation.
    You must calculate the temperature rise above the maximum specified ambient operating temperature.

    Coil resistance will most probably be proportional to absolute temperature.

    I assume you are using DC current. DC and AC solenoids behave differently since the inductive component of the coil limits AC current without the heat generation.
  4. Dec 22, 2013 #3


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    A huge factor in this will be the cooling provision you make. If you want something you can really rely on then you really ought to look at the specifications and on what is actual practice in manufacturing. Trying just to base any design on theory alone risks catastrophic failure. There must be loads of readily available design figures for motors and transformers, to help you with this. The cost of a failure makes it worth even paying for some reliable advice. The right solution will cost you less in the end.
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