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Solar dishwasher is up and running

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OperaHouse:
My wife had been complaining about washing dishes at the camp.  Came home a couple weeks ago from town recycling with a 2 year old GE dishwasher.  Guy was about to toss it in the dumpster when I asked to have it said it was hit by lightning. It had indeed taken a major strike, but the protection devices had done their job and damage was limited to power section.

Turns out the major load of a dishwasher is the heating element.  Pumps and everything else is limited to 100W peak and generally runs at about 65W.  I have 120F water and the control system will fault if water temps don't reach 120F during wash cycle.  120V heating element is 17 ohms. At 60V panel DC buss that will give about 1/4 the heating and these don't really use that much water each cycle.  A fill doesn't consume enough water to get hot water to the washer.

My initial solution was to add extra insulation to the housing, externally power the heater from the 60V PV buss switched on and off by the dishwasher control, and run the discharge pump for 20 seconds anytime the fill valve is operated.  I had noticed when testing the washer in the garage that the discharge pump would turn on and off every couple seconds for a few times.  Figured that was some feature to prevent screen clogging.  When dishwasher was finally installed, for the first 20 seconds of fill the water would just dribble out.  Turns out this on/off cycle was to get rid of air trapped in the pump.  Moving on I just removed the interval on timer and decided to see how it would work without it. 

So far with three washings water temp hasn't been an issue. Normal cycle takes about 80WH in a 50 minute period.  I only ask her to run hot water at the sink for a minute to warm up the pipes and do dishes mid day.  And heated dry doesn't really cost me anything. No need for a big inverter.  I use a 700W MSW with the fans removed to save power.  The control system fits nicely in this old alarm cabinet.

kitestrings:
Sounds like a good solution, and nice re-use of an appliance headed for the curb.

We have a "dish drawer" I think it's called.  F& P makes a split dishwasher that has a separate upper and lower drawer, with the idea being that you run just the upper section for the normal, light duty, day to day, and the lower section for pots and pans.  We have just the upper section and just try to be more creative about loading it.  Similarly, I try to run the hot water tap for a couple minutes to get the water from our on-demand (LPG) water heater to the kitchen before kicking it off.

Most days, particularly in the summer we use the built in timer - many newer models you can press to turn on, or press and hold to scroll to a 1, 2, 3 ,4-hr delay - to set it to begin mid-afternoon so it coincides with our solar production for the day.

OperaHouse:
The more things change, the more they stay they stay the same.  I was cooking breakfast and was looking for  particular pot. Asked my wife if the dishes in the washer were clean, "No, I'm waiting for the sun."  The delay timers are nice.

I have some washing machine fill valves.  Instead of running the pump, I think I'll just have this valve open to dump some water before the fill valve is operated.  So far it has not thrown any temp faults so that is in the that would be nice list to do.  Next year I will mod up a large LG washer to work on solar and avoid generator noise.

kitestrings:
Regarding "are they clean?"...

We put together a magnetic photo frame where in one half there's a picture of one of the kids contemplating a puddle, if you flip it you see the same kid after his decision...

Bruce S:
OperaHouse;
If you run the fill valve , won't the water level sensor in the tub part of the dishwasher kick in and pump that water out?
OR is this what you intend to do so it cycles the temperate water?

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