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Old 10-08-2017, 07:06 PM   #21
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Did you find the power label yet?
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Old 10-08-2017, 07:23 PM   #22
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If there are no specs on the current draw and you don't have a clamp-on ammeter, buy a $20 Kill-A-Watt meter to measure its start-up and running power requirements.
Ditto on the”Kill-A-Watt meter
Run for several days and average the usage.
Have done this and it pretty acurate.
Back into the wattage to determine your batt bank size and inverter size.
Go with pure sign wave, and go bigger, you will find many more uses for it.
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Old 10-08-2017, 08:29 PM   #23
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Do not buy a much bigger inverter than you need. Their efficiency is usually highest near peak.
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Old 10-08-2017, 09:44 PM   #24
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Interesting side issues but for a dedicated inverter (not my choice by any means) most will be big enough. Typical refrigerator will draw 300 watts during the defrost cycle and less than 200 for operations. A 1000 watt inverter should take care of the start up draw.

But then I am just guessing.


I don't know where you get your 300 watts but my inverter's load meter indicated 800 watts were used for my Summit 8.2cuft fridge in the defrost mode.

And those who plan to purchase a 1KW inverter for a fridge with auto defrost should consider going with a higher wattage unit.....but it's your money
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Old 10-08-2017, 09:46 PM   #25
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Do not buy a much bigger inverter than you need. Their efficiency is usually highest near peak.
If you're that concerned about energy, I suggest you use ice instead of refrigeration
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Old 10-08-2017, 10:04 PM   #26
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You got a good inverter for that price. How long have you been using it?
EDECOA Power Inverter 3500W 7000W Pure Sine Wave 12V dc to ac 120V LCD Display

The seller asked a higher price than I paid because he advertised "or best offer." I just recently (August) purchased and installed it.

I suggested something much lower and he reduced his sale price to that I quoted earlier. Life expectancy! Who knows! This I do know, the inverter that went smokey worked better, lasted much longer than my old Xantrex. And yes indeed, I did kill it with our microwave. Maybe the manufacturer overrated the inverter for sales purposes. And that thought crossed my mind when I could have purchased an inverter with a lower rating than I did.

My inverters have always operated 24/7 and see loads only when there is no dock or genny power available. Efficiency??? Who cares! I have 860 AHs of golf carts providing 12vdc plus 1180 watts of solar. But most modern inverters operate with efficiency greater than 90% at full load. At lower loads the efficiency will drop but the total power consumed will of course be less. If in doubt, check the heat of an idle inverter yourself vs one operating under load.
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Old 10-08-2017, 10:16 PM   #27
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I went the cheap route with a Cheap Chinese Crap (CCC) Xantrex 1000W nine years ago for about $120. Five years later, I fried it by my own fault and replaced it for the same cost, then that one died under the 1-year warranty and Xantrex replaced it no questions. Then I bought another one for $110 that sits in shrink wrap in my onboard spares. So all in, I've got $240 in 9 years of inverter use plus $110 for a spare.

It's used to run a 3 cu ft apt fridge, 900W microwave and an electric skillet. It can run any 2 of the 3 simultaneously.
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Old 10-08-2017, 10:21 PM   #28
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Al-- the inverter I posted the URL to is Chinese. Cost was just over $100/KW
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Old 10-08-2017, 11:30 PM   #29
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Al-- the inverter I posted the URL to is Chinese. Cost was just over $100/KW
I saw that. Good prices for a pure sine wave inverter.
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Old 10-09-2017, 07:03 AM   #30
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Sine wave units are usually required to get the best out of heavy loads, air cond etc.

The cheap square wave units are great at small 120V RV or house fridges.

These reefers do not have TX valves to modulate the refrigerant flow , they simply have a pin hole the refrigerant sprays thru.

The head pressure is bled off very rapidly when the unit stops, so large amperage is not required to start it a few min later.

The house fridge danger is the hot door seals and heaters to dry out the thin insulation is not measured in the annual consumption claim.

These heaters can use as much energy as operating the fridge.

Look up the fridge on line from the mfg repair lit before purchase and see how much energy is required.

Although more expensive RV fridges usually have better insulation and no heaters.
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Old 10-09-2017, 07:57 AM   #31
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Originally Posted by foggysail View Post
I don't know where you get your 300 watts but my inverter's load meter indicated 800 watts were used for my Summit 8.2cuft fridge in the defrost mode.

And those who plan to purchase a 1KW inverter for a fridge with auto defrost should consider going with a higher wattage unit.....but it's your money
Appears I am another victim of relying on what is on the internet to be true. You think I would know better. Googled average watts used by a refrigerator in defrost cycle.
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Old 10-09-2017, 09:42 AM   #32
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Appears I am another victim of relying on what is on the internet to be true. You think I would know better. Googled average watts used by a refrigerator in defrost cycle.

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Old 10-09-2017, 11:21 AM   #33
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For a dedicated inverter don’t go “big”. In between compressor runs a bigger inverter uses more power in standby than a smaller inverter. That’s just wasted Amp-hrs.
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