I am looking at a Zanussi (Electrolux) ZSF 2420.
Normal cycle:
Water: 7 Litres
Washing time with drying: 94mins
Drying time: 13 mins
Energy: 0.8Kw (800 watts)
Fuse:13amps
Vac: 230VAC/50Hz
Heating Element: 1000w
Power rating 1080w.
So 800watts/230V=3.4Amps for 1.5 hours = 5.2 amp hours
So 5.2 amp-hours and 7 litres of water seems pretty reasonable.
The size is fine for two people and can fit pots and pans etc.
A couple things here. First, what they are calling "Energy" should probably be watt-hours or Kw-hours, which is the right unit for energy.
Since it has a 1000 W heating element, and a power rating of 1080 W (watts is a unit of power), its complete washing/drying cycle probably totals up 800 W-h of electrical energy.
Second, amp-hours is shorthand for energy usage from batteries at 12 volts, not 230. That 800 W-h at 12 v = 800/12 = 66.7 a-h. Xantrex gives an efficiency level of 85% for their Freedom inverters, so this would mean 78.4 a-h drawn from the batteries.
It's not insurmountable, but it might be cheaper overall to invest in a little Honda portable generator and use this to power the dishwasher directly. That'll save the need for a couple hundred extra a-h of battery bank, a big inverter, a big engine alternator and a couple extra hours of main engine use every dishwasher cycle. The little generator would also charge your batteries from regular house loads for less cost than running the engine, too boot.
Tim
you are absolutely right the normal cycle consumes 800 Watt-hours of energy over 1.5 hours. So this mean average power consumption of
800watt-hours/1.5hours=530watts.
So 530watts/12v ~ 45 amp draw.
For 1.5 hrs ~ 67.5ah and so 78 ah @ 85% efficiency.
On Eco it uses 630watt-hours (54mins), so 52.5ah @85%eff ~ 62ah
But yes, quite a lot of power to replace using an alternator, wind gen and solar. So probably need an APU or genset of some kind.
Yes it did seem too good to be true. The heating part of the cycle must consume a lot of power.
I think if guys did the washing up there would be more dishwashers on boats. In any case I think for long term live-aboard away from the marina it would be worthwhile. As would a washing machine.
So the question becomes what size boat and genset/ battery bank would be needed to comfortably generate enough energy (and water) to run this system?
I guess we could round up the required power consumption to include generating 7 litres of water as well as one run of the dishwasher a day to say 100 ah.
A washing machine uses ~45 litres and 1000 watt-hours so 83 amp-hours.
So around 100 amp-hours.
So on average 200 ah every second day would require 100ah perday on top of other energy requirements.
So looks like running a genset or maybe the honda once a day for an hour would the only way to keep up with this sort of drain.
Thanks Tim, I forgot the constant in P=V I is the P.
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