Forum Discussion

sayoung's avatar
sayoung
Explorer
Jul 18, 2016

Refrigerator current draw ?

My 5er is at the lake an hour away is why asking. I was wondering how much power the standard norcold fridge uses on 115v, been thinking if it wouldn't break the bank if adding the dual alternator kit or large single to power inverter on truck . This would go back & plug to a shore power plug already added to front to plug in genny.
May be too much wattage required to keep fridge on this way while traveling, I know that several here keep the propane on but I won't after all my years in the AC/heating business .
  • sayoung's avatar
    sayoung
    Explorer
    Jul 18, 2016
    CA Traveler wrote:
    Since propane is out for you you could go the 12V and inverter route. But be advised that if you refer is 240W it draws 2A AC and about 22A for the inverter. For that DC draw you need much heavier wires from the alternator to the inverter. Installing the inverter in the truck may be the better option.


    Installing on truck is plan as I need 115 v once in a blue moon to run some tools.
    Also, to " We can't Wait", in the Tx sun a 5 to 7 hr drive & not even out of the state is common so the fridge does warm up some. We like the Tx Hill Country when traveling.
  • We_Cant_Wait's avatar
    We_Cant_Wait
    Explorer
    Jul 18, 2016
    If it's only an 1 hr drive and you go on shore power once there I would just turn the fridge off. It's good for 6-7 hrs if you keep the door closed with no power to it.
  • Kayteg1's avatar
    Kayteg1
    Explorer II
    Jul 18, 2016
    The difference could be that at 68F you had the tomatoes at the bottom of the fridge frozen and at 86F not.
    Lot depends on thermostat setting.
    For me 12V consumption is more important and I like mine 15.7amp as I use 30 amp truck charging while on the road.
  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    Jul 18, 2016
    Since propane is out for you you could go the 12V and inverter route. But be advised that if you refer is 240W it draws 2A AC and about 22A for the inverter. For that DC draw you need much heavier wires from the alternator to the inverter. Installing the inverter in the truck may be the better option.
  • pianotuna's avatar
    pianotuna
    Nomad III
    Jul 18, 2016
    Hi,

    I did not guess. I measured the consumption for 24 hours using a kill-a-watt. It seems to make very little difference what the ambient temperature is. I've done this at an ambient temperature of 20 c (68 f) and at 30 C (86 f). The results were practically identical.

    Kayteg1 wrote:
    Don't think it cycles off a lot in our weather.
  • Kayteg1's avatar
    Kayteg1
    Explorer II
    Jul 18, 2016
    My refrigerator with separate freezer is rated 2.8 amp @120V and I did not measure the actual draw.
    At 12 V it is rated 18 amp and actuall is 15.7 amp.
    Don't think it cycles off a lot in our weather.
  • sayoung's avatar
    sayoung
    Explorer
    Jul 18, 2016
    Thank you.
    At that draw probably wouldn't need anything but an inverter as my Duramax has 2 parallel batteries now & I think the alternator is 105 amps max output.
    This would be easy to add rain proof 115 outlet in rear & make short cord .As I mentioned, already added a 50amp plug at front & transfer switch to use a gen to run AC when stopped for break. We have 2 dogs that travel sometimes as they must have daily meds.
  • pianotuna's avatar
    pianotuna
    Nomad III
    Jul 18, 2016
    Hi,

    Absorption fridges use about 5.7 kwh per day. The duty cycle on mine is 2:3. It draws 325 watts when it is in cooling mode. That can easily be handled by a 400 watt inverter.

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