What size inverter for a chest freezer

[bigislandhikers]

I am looking at getting a chest freezer. The tag on the back says it draws 1.7 amps. So running wattage would be 1.7x120 = 204 watts....right?

The tag didn't say anything about starting amps. Does anyone have a guess about what the starting wattage would be so I can make sure I have an inverter large enough?

Thanks
BIH

[dragogt]

Are you looking for a "plug in" or hard wired??

[bigislandhikers]

Originally Posted by dragogt

Are you looking for a "plug in" or hard wired??

Plug in.

Until I finally get a generator looking for backup power for a day or two.

Thanks
BIH

[dragogt]

Than I would get the Biggest you can find, because the ext cord will add some load to it as well...

Check the pawn shops in your area, I got a 1000W one for like 60 bucks..

[Swampwood]

Bigger the better, at least a 750W. Smaller ones heat up faster. Try to make all your wiring 10g too.

[bigislandhikers]

I called GE and they say I need 3 times the wattage to run this freezer. So that would be about a 600 watt inverter. I also called Cobra Electronics and they said I would need their 2500 watt inverter. Not sure.

[dragogt]

Have you checked the pawnshops yet? I'd pick up about a 1k Watt one and try it out to see how it works...

[Fatbastard]

An inverter should have a little room for starting power. My Cobra 1500 says it will start at 2000.
I had a Vector 1000 for years. I used it when otr trucking for a fridge and microwave in the truck. Then I put it in a service truck and used it to run power tools so I didn't have to buy all cordless tools. It ran everything, grinders, drills, dremels, shop vac, hammer drills, sawzall, skillsaw. I finally smoked it when I was drilling a 5/8 hole in 3/8 inch steel. The bit bound up, and I laid into the trigger on the big 1/2 inch drill and she let the smoke out. After ten plus years of bouncing around with me all over the country.

1000 should be plenty for your freezer and more. The Vectors are cheaper than the Cobras at most places. Truck stops carry a good selection, and I purchased my first one with fuel reward points

Edit: I just noticed the plug in part, I don't think you will get a plug in over 500 or 600. I think both of my plug ins are 400.
My 1000 and 1500 ran on 4 gauge cable directly from the battery top posts. Running it directly off the battery with large cables will help it run cooler and make it less likely to trip the overload sensor. Just remember to fuse it.

[panhapp]

There should be a tag on the compressor that gives the LRA (Locked Rotor Amps) . This is about the max the freezer will draw at start up.

Pan

[bigislandhikers]

Originally Posted by Fatbastard

An inverter should have a little room for starting power. My Cobra 1500 says it will start at 2000.
I had a Vector 1000 for years. I used it when otr trucking for a fridge and microwave in the truck. Then I put it in a service truck and used it to run power tools so I didn't have to buy all cordless tools. It ran everything, grinders, drills, dremels, shop vac, hammer drills, sawzall, skillsaw. I finally smoked it when I was drilling a 5/8 hole in 3/8 inch steel. The bit bound up, and I laid into the trigger on the big 1/2 inch drill and she let the smoke out. After ten plus years of bouncing around with me all over the country.

1000 should be plenty for your freezer and more. The Vectors are cheaper than the Cobras at most places. Truck stops carry a good selection, and I purchased my first one with fuel reward points

Edit: I just noticed the plug in part, I don't think you will get a plug in over 500 or 600. I think both of my plug ins are 400.
My 1000 and 1500 ran on 4 gauge cable directly from the battery top posts. Running it directly off the battery with large cables will help it run cooler and make it less likely to trip the overload sensor. Just remember to fuse it.

Ok, Im slow. I will be running off a battery with cables. I think I misunderstood his previous question.

Whats up with a fuse?

Thanks
BIH

[Skvez]

If it says it draws 1.7A then running VA will be 120V* 1.7A = 204VA
You can assume a unity power factor and say that is 204W (it will actually be a lagging power factor).
Start-up current for a motor is typically 3 to 7 times running current.
Lets say 5 times and you can abuse the inverter for a short while if it's more.
A 1000W inverter should be adequate.

In theory an 8A fuse will blow before the inverter does if you overload it, they're a lot cheaper to replace.
In practice fuses have slow blow characteristics (even 'quick blow' fuses are slow compared to transistors). I'd be tempted to protect this with a 6A MCB (Minature Circuit Breaker)

[LEPER]

How the freezer will be used will affect the inverter choice. Do you want a modified square wave(many people refer to this as modified sine wave, incorrectly) or a true sine inverter. What batteries? The Ah battery rating will let you know how much power is available. Remember to not discharge past 50% How many batteries will you have. Will you have any? Will you be running straight from the genny?

MSW inverters are cheap compared to the true sine counterparts. Both will put their own draw on whatever power source you are using. True Sine will safely power most electronics, MSW can have devastating effects on sensitive electronics. Even something with a digital timer may not work with MSW inverters.

[Fatbastard]

Originally Posted by bigislandhikers

Ok, Im slow. I will be running off a battery with cables. I think I misunderstood his previous question.

Whats up with a fuse?

Thanks
BIH

You need to put a fuse in whatever cable you run from a battery to power the inverter. Mine has 200 amp fuse like you would see for a big car stereo amp. I don't fuse it coming out of the inverter, it has outlets built in.
I thought what was meant by "plug in" was you want to plug it into a power outlet in a car "cigarette lighter". I was assuming you want to use it in a car (now who is slow). You probably meant you want to plug the appliance directly into the inverter.

One thing I like about my Cobra, it has a digital display that toggles between input voltage and output current. Helps me keep an eye on the battery. With the Vector, I would just run the truck if I knew it was a decent load like the microwave or bigger tools.
I have not looked into them much, but I bet the wire in ones that are meant for home use are cheaper, unless they are the "true sine" ones.

Camping world or an rv parts store should have some in stock too. I have seen both plug in and wire in types in rv's and travel trailers. Maybe you have an rv salvage yard in your area?

[sendkeys]

Originally Posted by LEPER

How the freezer will be used will affect the inverter choice. Do you want a modified square wave(many people refer to this as modified sine wave, incorrectly) or a true sine inverter. What batteries? The Ah battery rating will let you know how much power is available. Remember to not discharge past 50% How many batteries will you have. Will you have any? Will you be running straight from the genny?

MSW inverters are cheap compared to the true sine counterparts. Both will put their own draw on whatever power source you are using. True Sine will safely power most electronics, MSW can have devastating effects on sensitive electronics. Even something with a digital timer may not work with MSW inverters.

Other than cleaner power and less damage to what are you are running.
A pure sign invert can be rated lower for surge watts.


An example
I needed to do a remote system for strobe lights. They have high surge requirements but little power usage.

I bought a genetic($100) 1000 watt invert with 2000 watt peak.
You would think "hay 2000 watts thats 16 amps thats more than most normal household sockets"....It couldn't even power 1 strobe without alarming out.

I then bought a samlex($240) pure wave 600 watt 1000 watt peak.
It was able to power two strobe and maybe even more.

[dragogt]

OP

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