3-way fridge - am I missing something?

Discussion in 'The Beginner' started by Gary217, May 15, 2016.

  1. Gary217

    Gary217 Funster

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    Thought i'd better go back to the 'beginner's class' for this question...

    We've just had a week away on our van, and this one has a Dometic 3-way fridge while our previous VW just a little (but very effective) Weaco compressor fridge. The old compressor fridge was easy, turn it on and it ran and so long as the leisure battery got a charge within around 36 hours (either driving or on hook up) it did its stuff with no need to do anything.

    Our new 3-way requires us to switch it between the various sources, when driving red switch for leisure battery, when hooked up green switch for mains and when parked away from hook-up, turn on the gas and orange switch to fire it up. On our trip, yep, a couple of times I forgot to switch from leisure battery to gas when parking up and leaving the van for a few hours. I'm also just a teeny bit nervous about leaving the gas running while we go off on our hikes.

    Surely if it is charged the leisure battery could cope with running the fridge for a period while we are parked up to save having to put on the gas each time? I've double checked and our fridge does not run off the leisure battery unless the engine is running (and we also found out by having a warmish fridge after 5 hours away from the van...I was not popular!).

    I appreciate that having the gas option is great if parked up overnight away from mains power, but I'm wondering if their is a way of over-riding the switch that stops the fridge running on leisure battery when the ignition/engine is off so we could let it run on when we park up for just a few hours away from power?

    Thanks
     
  2. NickNic

    NickNic Funster Life Member

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    It doesn't run from the leisure battery.

    The 12V setting is power from the engine battery which is why it should only be used on that setting when driving.
     
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  3. icantremember

    icantremember Funster

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    As NickNic says 12v is only for while the engine is running.

    It should be perfectly safe to leave running on lpg.
     
  4. pappajohn

    pappajohn Funster Life Member

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    The 12v supply is via a split charge relay which is triggered by the alternator running.
    You could bypass the relay but rest assured....you WILL flatten the battery at some point ans as its the engine battery you can't start the engine to charge it.
    Thousands of vans all over the world.run the fridge on gas while unoccupied but you very rarely hear of vans catching fire.
     
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  5. Gary217

    Gary217 Funster

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    Thanks for the prompt replies...not surprised by what you said and we'll just have to get used to it.

    Thanks!
     
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  6. NickNic

    NickNic Funster Life Member

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    Also the 12v setting is the least effective of the three. All it's really meant for is to maintain the temperature whilst you're travelling, not to actually get it cold in the first place.
     
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  7. Hils and Glenns

    Hils and Glenns Funster

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    Hmmm I didn't know you could run the fridge from the battery while driving. We always set ours to gas. What does it run on if you set it to auto while you're driving?
     
  8. scotjimland

    scotjimland Funster Life Member

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    agreed but the 12v heaters are now much better than they used to be...

    typically the 12v heater is 130watt and the mains heater being 135watt .. so not a huge difference.. smaller units are 120 watt / 125watt

    setting off from home without pre cooling it will still cool down perfectly well .. not the best idea of course as it will take a while.. we always pre cool on mains overnight before setting off
     
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  9. NickNic

    NickNic Funster Life Member

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    On Auto it runs on 12V when the engine is running

    Remember that it does not run from the leisure battery, it takes power from the engine battery/alternator.

    The only situation where running it on 12V is intended is whilst driving.
     
  10. Zigisla

    Zigisla Funster

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    I used to switch on 12 v on auto when I picked up the MH from storage and then load the fridge at home and set off. When parked up or stopped for good always switches to gas. Unless of course I forget to turn it on:rolleyes: As the MH is on the way to work, I now switch on the fridge and turn on gas so that when I come back collect it at mid day the fridge is now much cooler than it was before. As I drive away it switches back to 12 v to maintain temp. Keep forgetting to turn on gas when I stop or park up though so may have to invest in a crash valve thingy so I can drive with it switched on. (y)
     
  11. JJ

    JJ Funster

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    The fridge you used to have was, as you know, a compressor fridge.

    The one you have now is an absorbtion fridge.

    The former used less electrical power because it was switched on and off regularly by the thermostat. The latter doesn't... so keeps drawing a LOT of electricity all the time it is switched on.

    Almost all motorhomes have their fridges wired to the engine battery and will only use 12 volts when the engine is actually running.

    When parked it should be on gas or 240 volt when available.

    When parked, I have used my 3 way fridge on gas for years and years and years without any problems whatsoever.

    JJ :cool:
     
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  12. scotjimland

    scotjimland Funster Life Member

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    are you sure about this JJ ;)

    since you mentioned it.. what happened to your compressor fridge ?:whistle:
     
  13. JJ

    JJ Funster

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    Well Jim, I am CERTAIN where ALL the absorbtion fridges I have ever owned are concerned, but the modern ones may be different now...

    The posh compressor fridge I had in the Wagon let all its gas escape... I had only had it for 10 years(ish).

    The bloody expensive, poorly designed on several levals, Engle (portable if you are an accomplished weight lifter) fridge is called into service here a QMJ. For all its many faults, the one thing it really does do really well is make things cold (or frozen).

    It gets its power (it needs lots as the compressor cooling fan runs permanently whether the compressor is running or not) from the old Wagon's two remaining solar panels.

    JJ :cool:
     
  14. scotjimland

    scotjimland Funster Life Member

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    Mine is 15 years old and I can say for certainty that it has a thermostat on 240v ..

    but correct, not on 12vdc when travelling.

    I believe the new 7 Series have a thermostat in 12v energy mode

    I found your old thread and tale of woe with the Engle .. :LOL: what a saga

    EDIT

    just found this

    Running on 12 Volts

    The 12V operation is for ‘on the road’ use and will only operate when the towing vehicle engine is running, but it is not a ‘second best’. On the contrary, cooling in this mode is just as good as it is on gas or mains electricity. However, remember that in 12v operation, cooling only operates at the maximum setting – there is no thermostat fitted in the 12V circuit unless you have one of the new Dometic 7 series refrigerators. Also, because of the relatively high current consumption of a refrigerator when on 12V (approximately 7 - 13 amps depending on model), mains or gas should be used whilst on site.
     
  15. Old Soldier

    Old Soldier Funster

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    My old fridge in Elle has a warning lamp in the 12v toggle switch so even if the switch is still "on" It does not light up if the engine is not running. I always leave that 12v switch turned on, it does not affect the running of the fridge when on either gas or mains, but always tops it up when on the move.
     
  16. tonyidle

    tonyidle Funster

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    On Dometic fridges I've always left both mains and 12v switched on (where possible - some had a combined switch) on the basis that if the van is moving it isn't on mains & if it's stopped it isn't getting 12v. When gas is in use it is only because the van is stationary & not on EHU. I've never understood the need for either mains or 12v controls - let alone AES.
     
  17. glenn2926

    glenn2926 Funster

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    When EHU is available I use it, when not it runs on gas. Yes even when on the move( ducks and waits for the in coming) I have done this ever since we had the gas tank fitted and all has been fine. The van is permanently on EHU at home, so fridge is always cold. This sometimes useful if the fridge in our house is full and more room is required.
     
  18. scotjimland

    scotjimland Funster Life Member

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    brave post ....:LOL:

    [​IMG]
     
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  19. TheBig1

    TheBig1 Funster Life Member

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    a point about newer 3 way fridges, there is an extra terminal that means they can be wired to solar panels.
    everything seems to evolve, and i well remember using just gas powered fridges, then 2 way, then 3 way, then AES automatic energy source. none of them were rocket science and you have to teach your brain to throw switches or set the temperature. nothing worse than warm beer
     
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  20. scotjimland

    scotjimland Funster Life Member

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    likewise

    an early one I had was lit using a wheel and flint.. like a Zippo lighter fitted near the gas jet..

    when it wouldn't light I used lit piece of newspaper .. threw it underneath :eek:.. that got the sucker lit :cool: :LOL:
     
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