Washing machine from inverter

[gary955]

I have an old hot and cold fill washing machine that I'm thinking of bringing aboard the boat. It has an electro-mechanical programmer rather than an digital one so I think it will still work with the heater disconnected altogether. I have no generator but do have a 1500w psw inverter with a peak output of 3000w. Doable? and if so what sort of a bashing will it give to my 3x 120ah battery's? I could wash while running the engine but I only have a 55A alternator.

[Nightwatch]

If you are filling with hot water it shouldn't be too bad. Regarding your mechanical programme thingy, I've no idea I'm afraid.

[Alan de Enfield]

If it works with the heater element disconnected then you should be fine.

 

As a rough guide every 10 watts takes 1 Ah from your battery.

 

So (for example) running a 1000 watt washing machine for 1 hour would use 100 Ah from your batteries.

 

When your batteries were new you had 360Ah of batteries of which (realistically) 50% (180 Ah was usable), as batteries age they lose their capacity and they could be as low as 50% of what they should be - so you could have available 50% of 50% of 360Ah - or - 90Ah.

It is all speculation without knowing how well you have maintained your batteries and what their current capacity is.

Edited March 25, 2016 by Alan de Enfield

[Robbo]

You may find that the timing is still based on the wave length on the old mechanical ones as well so it may still have issues. Only one way to find out tho. 55amp will be enough to power the machine for the majority of the time (it's only really the heater that would use more, but your batteries will be used as a buffer) if your inverter can cope.

[Martin Megson]

I live aboard and use my washing machine through the inverter. I only use with the engine running which eases the load on the batteries

[Tom and Bex]

We run an old candy washing machine from our msw inverter with heater disconnected and it runs fine. Surprising how little it takes from the batteries with no heating element.

 

Some washing machines however will just sit there and not advance if the water is not up to the expected temperature. If that is the case just advancing it one click on the programme dial should get round the problem. Not something you can do with the modern electronic machines!

 

Tom

[gary955]

Cheers all. I think I'll give it a try

[Nightwatch]

I live aboard and use my washing machine through the inverter. I only use with the engine running which eases the load on the batteries

Ditto. We fill with hot water via a hose at the same time as the machine is taking cold water. Guesstimate the temperature.

 

Works for us. I've even trained the washer woman to do it now, I don't need to get involved now.

 

Martyn

[GUMPY]

It wont work with the heater disconnected as most H&C fill machines only take in cold, unless you are doing a 90deg wash, then heat the water as needed.

[gary955]

It wont work with the heater disconnected as most H&C fill machines only take in cold, unless you are doing a 90deg wash, then heat the water as needed.

Oh Dear. That would be a problem then, would a 1500w invertor run the heater even if the battery bank had sufficient capacity?

[ditchcrawler]

Oh Dear. That would be a problem then, would a 1500w invertor run the heater even if the battery bank had sufficient capacity?

Cant you fill with hot water manually ?

[nicknorman]

Oh Dear. That would be a problem then, would a 1500w invertor run the heater even if the battery bank had sufficient capacity?

It is only for the first fill which is the wash, the remainder of fills are for rinsing and that is always cold. If you fill the wash cycle with cold water and disconnect the heater, chances are the programme will wait in perpetuity for the water to reach the selected temperature before moving on, so to get around that simply fill the washer with hot water mixed with the incoming cold. This could for example be by pouring a couple of kettles full of very hot water into the soap dispenser. Or for a more permanent solution fit a mixer valve before the water input so that you can select warm/hot water for the first fill (wash) and then change it to cold for the remainder of the wash. A washer doesn't used much power for washing except for the heater and certainly a 55A alternator will be more than capable if the heater is disconnected.

[Robbo]

Oh Dear. That would be a problem then, would a 1500w invertor run the heater even if the battery bank had sufficient capacity?

Have a look at the back of the washing machine for the power consumpution figures, or use one of those plug in devices. My guess is that your inverter may be just too underpowered.

[alan_fincher]

Oh Dear. That would be a problem then, would a 1500w invertor run the heater even if the battery bank had sufficient capacity?

 

It is worth noting that even if your 55 amp alternator were capable of delivering 55 amps continually, which it will not be), that running flat out it can only produce about 660 watts. I would be surprised if you will actually better 500 watts.

 

Therefore, if you try driving a 1,500 watt load, only about 1/3 of the requirement will come directly from the alternator, and the remaining 2/3 will still be by depleting the batteries.

 

So even if there is the capacity in the bank to supply this, to put it back again you would need to run the engine for twice as long again at least afterwards, as you have already run it with the 1,500 watt load attached.

[nicknorman]

It is worth noting that even if your 55 amp alternator were capable of delivering 55 amps continually, which it will not be), that running flat out it can only produce about 660 watts. I would be surprised if you will actually better 500 watts.

.

Why do you say it won't be capable of 55A continuously? When using such an alternator to charge batteries yes the rise in battery voltage can cause the alternator to reduce from max output fairly quickly. However when using it to power an inverter it is a different situation - the inverter keeps the system voltage low and so the alternator remains on max output. OK so if the alternator is badly cooled eg not running fast enough or in a very hot engine room, yes there can be some output reduction due to thermal effects but in my experience it's not much.

[GUMPY]

Easy way is to do a cold wash......

Have a read of this

http://www.canalworld.net/forums/index.php?showtopic=27569

Edited March 25, 2016 by Loddon

[gary955]

 

It is worth noting that even if your 55 amp alternator were capable of delivering 55 amps continually, which it will not be), that running flat out it can only produce about 660 watts. I would be surprised if you will actually better 500 watts.

 

Therefore, if you try driving a 1,500 watt load, only about 1/3 of the requirement will come directly from the alternator, and the remaining 2/3 will still be by depleting the batteries.

 

So even if there is the capacity in the bank to supply this, to put it back again you would need to run the engine for twice as long again at least afterwards, as you have already run it with the 1,500 watt load attached.

Are we saying then that the washing machine will draw the whole 1500w for the entire cycle? without the heater!

[Robbo]

It is worth noting that even if your 55 amp alternator were capable of delivering 55 amps continually, which it will not be), that running flat out it can only produce about 660 watts. I would be surprised if you will actually better 500 watts.

Therefore, if you try driving a 1,500 watt load, only about 1/3 of the requirement will come directly from the alternator, and the remaining 2/3 will still be by depleting the batteries.

 

So even if there is the capacity in the bank to supply this, to put it back again you would need to run the engine for twice as long again at least afterwards, as you have already run it with the 1,500 watt load attached.

The majority time of the washing cycle the machine will be pulling in a lot less than 500watt. Edited March 25, 2016 by Robbo

[Tiggs]

If the one click advance suggested by Tom and Bex does not work (or is too much hassle) then you could try and get a circuit diagram for it off the net and see if it is possible to over-ride the temperature sensor (should be possible).

 

You could control the temperature to what you want the input water to be with a thermostatic mixing valve; suggest 40 degrees works for most clothes.

 

Persoanaly, I would't bother trying to power the heater in the machine without a landline or a generator.

Edited March 25, 2016 by Tiggs

[dor]

If the washing machine is one that is designed to heat the water up to a particular temperature, and won't do anything until that temperature is reached, then as well as discinnecting the heater, bypass the thermostat as well. Use some hot water for the main wash which will be on a timer.

 

You won't need anything like the plated power as that will include the heater; you only need to ensure that you have enough inverter capacity to let the motor start. Once running it won't use much power.

 

A 1500W inverter with 3000W peak burst power should be adequate.

[Arthur Brown]

Your washing machine will draw small amps while he motor spins slowly for washing, more amps while in the spin dry part of the program and even MORE amps while the heater warms he wash water. For some periods while he drum is static maybe there will be no current consumed.

 

However washing machines have been reported here as probably the most difficult to drive from an inverter. Do try everything before you install the washer permanently.

[alan_fincher]

Are we saying then that the washing machine will draw the whole 1500w for the entire cycle? without the heater!

No,

 

I was merely picking up on a comment that referred to needing 1500w.

 

[gary955]

A quick google of washing machine heater elements would suggest that most are in the 1700w to 1950w range so I guess that a normal wash cycle would be beyond the capability of my inverter. With a hot fill at 40 degrees though it should be fine with the alternator easily keeping pace with the power consumption. have I got that right?

[Robbo]

A quick google of washing machine heater elements would suggest that most are in the 1700w to 1950w range so I guess that a normal wash cycle would be beyond the capability of my inverter. With a hot fill at 40 degrees though it should be fine with the alternator easily keeping pace with the power consumption. have I got that right?

It may be possible to get a low wattage heater? Will take longer and use the same amount of Ah's, but will save faffing with other methods like filling with hot water before hand.

[ditchcrawler]

It may be possible to get a low wattage heater? Will take longer and use the same amount of Ah's, but will save faffing with other methods like filling with hot water before hand.

I would say that is a very long shot