Running Dishwashers Off-grid

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Oggi
Oggi Registered Users Posts: 2 ✭
in Advanced Solar Electric Technical Forum #1
Just wondering if there have been any developments with dishwasher manufacturers providing lower wattage elements in their machines? My 240v dishwasher in AU pulls about 2000watts for the element when on which usually causes my off-grid inverter to switch to mains power. If the dishwasher had a 1000w element my 4.5kw off-grid PV array could manage that a lot better. Any news on this?
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #2
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    I just planned ahead and got a big inverter.    Dishwashers have pretty unique elements and the element is used for both heating the water and to dry.   I do a quick rinse with hot water to get the dishes and machine up to temp quicker than the heater can, but it adds 5 minutes to the cycle and an extra 2 gallons of water
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  • NANOcontrol
    NANOcontrol Registered Users Posts: 261 ✭✭✭
    #3
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    I have a newer dishwasher and it uses less than 100W without the heater element and 100WH per cycle.  I added extra insulation as these cabinets have a lot of heat loss and already have 120F water close. Instead of powering the element, I use that to turn on a relay. The heating element is powered by the 60V PV array.  So, the wife even has heated dry.  Just have to wash dishes mid day which isn't a problem. At reduced voltage the element is about 250W.   Heated dry is a 50/50 duty cycle each minute and I use a three minute timer to keep it on. Unconventional, but it works.
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  • Oggi
    Oggi Registered Users Posts: 2 ✭
    #4
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    Thanks for the comments. I have connected the DW to hotwater so running a rinse cycle before the wash cycle is a good idea although I have been advised that most dishwashers don't have thermostats, but the rinse is still a good idea if only using the shortest wash cycle so reducing the voltage to the element sounds like the easiest way to reduce overall current draw.
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  • NANOcontrol
    NANOcontrol Registered Users Posts: 261 ✭✭✭
    #5
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    "been advised that most dishwashers don't have thermostats"  Perhaps you shouldn't listen to that person. Any recent one does and it will throw an error code if it can't get the temp up to 120F after a couple of wash cycles.
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