Can a Household Refrigerator Work on a Sailboat ?

[a64pilot]

Originally Posted by SVI

Volts does not matter, watts are watts.

That would be why I put in parenthesis still 145 watts of course, I like to use watts as opposed to amps for that exact reason, but for some reason amps are most often used, easy conversion though, just multiply or divide by 10, if your talking 120 V vs 12V.

But yes, we can toss around theories forever, but real world statistical data always trumps theories, until it's measured it's a theory.
Now SC has measured her dorm fridge, we have real world numbers there, but do they scale up or does a high quality full size home fridge come with a much better insulation and better matched evaporators and condenser to the compressor, whereas a dorm fridge may have just used to parts that fit?

[koza50]

I just sold my Lagoon 500.As soon as I purchased the boat I got rid of all those small refrigerators and installed a Samsung 340lt fridge(without freezer).Boat came with 1260amp battery bank,2000w sinewave invertor and 600watt solar panels.We were liveaboards for 5 years,fridge and freezer(110lt frigoboat) ran all the time,no single problem.Energy consumption was nothing more than marine types,I'll go for the same set up in my next boat

[SVI]

Can confirm my 300l LG draws about 150w on average. Starting current is high, about 1000w. We are totally happy, very convenient.
Have 3kw Victron inverter.
I am putting 400ah of CALB LiFePo4 and 900w of solar on the roof.

[Cheechako]

Originally Posted by SVI

Can confirm my 300l LG draws about 150w on average. Starting current is high, about 1000w. We are totally happy, very convenient.
Have 3kw Victron inverter.
I am putting 400ah of CALB LiFePo4 and 900w of solar on the roof.

That's pretty good...I guess you are saying about 1.25 amps then ... or 30 a day... that's a lot better than any 12V system I've had....

[SVI]

Originally Posted by Cheechako

That's pretty good...I guess you are saying about 1.25 amps then ... or 30 a day... that's a lot better than any 12V system I've had....

LOL
150w is 12A on 12v.
But that ok - my teapot takes 250A )

[Cheechako]

Originally Posted by SVI

LOL
150w is 12A on 12v.
But that ok - my teapot takes 250A )

I assumed he was talking 12V... but come to think of it... not sure either makes sense...
12A at 12v would be 288 amps per day... ouch!

[SVI]

Originally Posted by Cheechako

I assumed he was talking 12V... but come to think of it... not sure either makes sense...
12A at 12v would be 288 amps per day... ouch!

Yes, we spend ca 350 amp-hours a day. But who cares if we have solar and generator (i can charge at 200amp consuming only 1liter an hour).

And 100gph watermaker is coming - we do not like to save water

[Cheechako]

My cruising budget was typically 120 amps per day... for everything.... (at anchor)

[Gone2long]

Originally Posted by 44'cruisingcat

You need an inverter. One that has a much higher rating than the fridge/freezer's motor, because on start up they draw much more. Say 3 or 4 times the motors wattage.

It's best to fit the inverter close to the batteries, because they need heavy cable on the 12 volt side.

Household fridges won't be as efficient as a proper boat fridge, they are not as well insulated. An improvement is to use a household freezer with a fridge thermostat.

But they are cheap, and some of the money you save can be spent on generating more power to run them.

Sounds like good advice. I have a similar problem. I bought a used refrigerator to use via shore power on my boat. The fridge was 110 and the power was 220, so I used a 220/110 "dual output" transformer. I plugged the 220 line into the 220 female of the transformer and the refrigerator into the 110 female.

The fridge ran for a while, but conked out after a day. Do you think that the problem was that I fried the fridge because the transformer wattage rating was too low? All comments and advice welcome.

As might seem obvious, I'm kinda new at all this.

Thanks,

G2L

[Cottontop]

Originally Posted by Gone2long

Sounds like good advice. I have a similar problem. I bought a used refrigerator to use via shore power on my boat. The fridge was 110 and the power was 220, so I used a 220/110 "dual output" transformer. I plugged the 220 line into the 220 female of the transformer and the refrigerator into the 110 female.

The fridge ran for a while, but conked out after a day. Do you think that the problem was that I fried the fridge because the transformer wattage rating was too low? All comments and advice welcome.

As might seem obvious, I'm kinda new at all this.

Thanks,

G2L

Wattage might have been the problem. You might also have had a frequency problem. Power is rated for both voltage and frequency. Typical US power, for instance, is 110v @ 60hz. Typical Europe power is 220v @ 50hz. A transformer will transform the voltage but not the frequency. Plugging 60hz devices into 50hz power, or vice-versa, will damage many (most).

[UNCIVILIZED]

I would think that you'd be able to find a 12vdc, or 24vdc motor to run things, in lieu of the AC one, would you not? It'd let you skip doing a lot of that extra wiring, plus the cost of an inverter, and the BIG hit of converting all of that energy from one form to another. The efficiency of doing that is often shockingly low.


Or (assuming I remember my electrical engineering right) if you have an "in" with the local fix-it guy, or McGuyver, just have'em rewire the AC motor to run on DC.


Not to go way OT, but the retro solution is to get a fridge which runs on propane or kerosene. They need to be kept fairly level, but I've seen them hung on bulkheads on big mono's. I had a small propane one when I lived on my Tri, & it worked fine.

[onestepcsy37]

I've heard of lpg and kero fridges but never actually seen one. An electric fridge offers the possibility of running it "for free" via solar and/or wind which makes it a better choice IMHO.

[Gone2long]

Originally Posted by Cottontop

Wattage might have been the problem. You might also have had a frequency problem. Power is rated for both voltage and frequency. Typical US power, for instance, is 110v @ 60hz. Typical Europe power is 220v @ 50hz. A transformer will transform the voltage but not the frequency. Plugging 60hz devices into 50hz power, or vice-versa, will damage many (most).

Hmmmm ... Could be that was the problem. Will check what the transformer says, but, why have a transformer, with a 220 and 110 female if plugging into 220 might harm what is on the 110 side? Seems like that doesn't really make sense; seems like what comes out of the 110 side would be 50 hz.

In such a case, how would one solve the dilemma? Are those "electronic" transformers more capable?

G2L

[GILow]

Originally Posted by onestepcsy37

I've heard of lpg and kero fridges but never actually seen one. An electric fridge offers the possibility of running it "for free" via solar and/or wind which makes it a better choice IMHO.

I have one in my bus, gas/12v/240v. It uses a HEAP of power on 12v since it needs to produce a lot of heat to work, something like a 25 - 30 amp current draw on 12 volts. That's ok when I am driving the engine alternator can produce plenty of power, and when we stop we run it on bottled gas. The amount of potential "heat" in a BBQ gas bottle is extraordinary, which of course, makes them lethal on boats, but they are ok on the bus. A gas bottle will do a year's worth of camping, easily.

It is very intolerant of being other than nearly perfectly upright. If I don't level the bus when we stop for the night it struggles to keep things cold.

All of which makes them pretty useless for boats.

Matt

[UNCIVILIZED]

Originally Posted by Gone2long

Hmmmm ... Could be that was the problem. Will check what the transformer says, but, why have a transformer, with a 220 and 110 female if plugging into 220 might harm what is on the 110 side? Seems like that doesn't really make sense; seems like what comes out of the 110 side would be 50 hz.

In such a case, how would one solve the dilemma? Are those "electronic" transformers more capable?

G2L

Going from 220v to 110v is pretty simple from an "engineering" as well as a practical perspective.
Also, it's not a big deal to change the hz of the power, from a theoretical standpoint either, though it does take more hardware. Plus you'll lose a good bit more energy doing that kind of "swap", than you do just halving or doubling the voltage without changing the electricity's frequency.
And yep, it's possible to do both at once; changing the voltage & the frequency. You just need the right equipment is all.