Power consumption? - Fridge/Freezer and Combi

Discussion in 'Fridges & Ovens' started by Roryboys Dad, Nov 4, 2014.

  1. Roryboys Dad

    Roryboys Dad Read Only Funster

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    We run the Dometic Fridge/Freezer on LPG when parked on site at night and we rarely use EHU.

    As I'm not an electric expert could anyone tell me, from studying the plate in the fridge, what power is required to run the fridge/freezer overnight and how much of a drain is it on the leisure battery.

    We run the temperature on a middle setting, three bars out of 5, and both compartments are usually fairly full.

    Or is the power used so minimal as to be irrelevant?

    Also how much power would a Combi 6E heater consume for a few hours at night now that the temperatures are starting to fall – it's thermal output is 1800W and it says power consumption at 230V is 3.9A/7.8A.

    Any help appreciated.

    Dometic  3.jpg
     
  2. ericroy

    ericroy Funster

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    When running the fridge will consume 170W/12v which is approximately 14Amps. However, it will probably only run for around 25% of the time. So over 10 hours it will consume 10 * 14 * .25 = 35 Amp hours. As your battery is probably around 110Ah, you would be using a third of the capacity just for the fridge. Given that the advice is to not run leisure batteries lower than 80% of their capacity, if you tried this you would risk shortening the life of the battery considerably.

    As you probably also run other 12v equipment such as lights and pumps, you will understand why the usual advice is to NOT run a three way fridge off 12v unless the vehicle engine is running and can provide the necessary power.

    You Truma 6E cannot provide heating from 12v. The 12v is used only to control the gas and/or mains electricity that heats air and water. So I am not sure quite what this part of your question means?
     
  3. pappajohn

    pappajohn Funster Life Member

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    As its an absorption fridge it wont run on 12v except when the engine is running then it will draw around 14amps.

    regarding the heating.....mains voltage or gas only.
    the 12v needed for the fridge and heater control boards is insignificant over a few days
     
  4. pappajohn

    pappajohn Funster Life Member

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    As a point of interest, on gas the fridge will consume approximately 1/4 ltr of gas in a 10hr night
     
  5. tonyidle

    tonyidle Funster

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    Unfortunately there's no thermostat when on 12v so the 170W is consumed constantly. The fridge is only intended for use on 12v when the vehicle is in use.
     
  6. ericroy

    ericroy Funster

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    In that case your battery would be completely expired by the morning!
     
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