I found a "free" inverter in my van!

[Daleford]

I am new to this and I have a couple electrical questions. I just bought a used cargo van [2020 Transit Connect] It has a bunch of shelving in the back and hiding in a corner was a 1000 watt Vanner pure sinewave inverter. I felt like I won the lottery! Now I am trying to figiure out what it will run as far as electrical appliances. I have 1990 small 120 volt microwave I was praying I could use. It has 7.3 amps, so it has 876 Watts. Am I going to be able to use it?

Next question: I am going to look at a "dorm" size small 120 volt refrigerator tomorrow morning. I will figure the watts once I see it, but I am wondering usually what do these small fridges have for watts draw?

 

[FlipperFla]

You would be pushing your inverter pretty hard, math is correct, should work. My 4.5 cf Danby Spec sheet says 1A, the meter on the inverter says 70W so somewhere between 115-70. We used to have a smaller one but we put so much stuff in it, it didn’t work correctly letting cold air to circulate between all the items. The 4.5 was a great improvement. The Danby was the only one I could find that was energy star rated. Found it on Amazon.

 

[maki2]

I put the little compact 700watt microwave I had on a kilowatt meter and it drew almost 1200 watts of AC. 700 watts is the smallest size microwaves I know of. Microwaves power ratings are funny that way. They pull more power than stated on the box advertising. It not the same technology as the electric coil heating elements such as found in electric skillets, griddles.

For your further information using lower power settings on a microwave does not mean it can be run on lower wattage. The microwave heat is controlled by fewer or more pulses per minute, however each pulse has the same power draw. That is also true for induction power cooking, it too is done with pulses that draw the same power. More frequent pulses are higher power cooking, less frequent are for lower temperature, slow cooking. So on those devices while your power use over time will be less for cooking at the lower temperature settings the size of the inverter needed stays the same no matter what you set the controls on.

But the electric coil type of heating device that is rated for 1,500 watts, the kind where you have a dial to control temperature, could be used on its lower heat settings on your 1,000 watt inverter.

So for that 1,000 watt inverter, electric skillet cooking on low or medium is a yes, but microwave cooking or induction cooktop burner cooking is a resounding no can do. There are two different electrical cooking technologies driving that situation.

 

[Daleford]

You would be pushing your inverter pretty hard, math is correct, should work. My 4.5 cf Danby Spec sheet says 1A, the meter on the inverter says 70W so somewhere between 115-70. We used to have a smaller one but we put so much stuff in it, it didn’t work correctly letting cold air to circulate between all the items. The 4.5 was a great improvement. The Danby was the only one I could find that was energy star rated. Found it on Amazon. ----------------------------------------------------------------------------------------------------------------------------- Amazingly with all the fridge brands out there this is a Danby as well ! Here is a pic. It has the energy star on the front. The seller doesn't know the size or the specs so I will check that out when I go see it tomorrow. Thanks for the help.

 

[FlipperFla]

A good ballpark rule of thumb with microwaves is whatever it advertised at the wattage to run it will be 2X so if your have a 800w microwave it’s going to take 1600w to run it. I found a GE microwave with a rounded back to fit in a corner on a countertop. Rated at 400 so it takes 800 to run it. Works great.

 

[tx2sturgis]

Actually, electric skillets use the same on-off principle to vary the temperature. A 1500 watt electric skillet will draw the full 1500 watts untill it reaches the desired setting, then it will maintain the temp by turning on and off.

But you can now buy small 600 watt electric skillets, I have not used one, and they probably cook slower than the bigger models, but that might allow one to be used on a smaller inverter.

But!

Heating and cooking with electrical appliances on battery/solar requires a large financial input to the hardware required for the production of power, or you can do the same job with propane for much less money.

 

[Happy Camper]

Regarding standard microwaves, the advice above is correct.

You can get an inverter microwave. They use 50% power at 50%. Not 100% half the time. The downside is that they are a bit larger. But if you have space, it would work for you.

Panasonic makes some good ones. Worth checking into if you are set on using a microwave.

 

[justanothermaroon]

I put the little compact 700watt microwave I had on a kilowatt meter and it drew almost 1200 watts of AC. 700 watts is the smallest size microwaves I know of. Microwaves power ratings are funny that way. They pull more power than stated on the box advertising. It not the same technology as the electric coil heating elements such as found in electric skillets, griddles.

For your further information using lower power settings on a microwave does not mean it can be run on lower wattage. The microwave heat is controlled by fewer or more pulses per minute, however each pulse has the same power draw. That is also true for induction power cooking, it too is done with pulses that draw the same power. More frequent pulses are higher power cooking, less frequent are for lower temperature, slow cooking. So on those devices while your power use over time will be less for cooking at the lower temperature settings the size of the inverter needed stays the same no matter what you set the controls on.

But the electric coil type of heating device that is rated for 1,500 watts, the kind where you have a dial to control temperature, could be used on its lower heat settings on your 1,000 watt inverter.

So for that 1,000 watt inverter, electric skillet cooking on low or medium is a yes, but microwave cooking or induction cooktop burner cooking is a resounding no can do. There are two different electrical cooking technologies driving that situation.

My Duxtop induction cooker varies wattage from 100-1800 depending on the temp setting.

 

[hugemoth]

Microwave ovens do not work well on modified sine wave inverters. They make a lot of noise and opperate at reduced power output. Dorm refrigerators, at least the ones I have, work fine on modified sine wave inverters. I used to use one powered by a 175 watt inverter so a 1000 watt should have no trouble running it.

 

[Daleford]

I put the little compact 700watt microwave I had on a kilowatt meter and it drew almost 1200 watts of AC. 700 watts is the smallest size microwaves I know of. Microwaves power ratings are funny that way. They pull more power than stated on the box advertising. It not the same technology as the electric coil heating elements such as found in electric skillets, griddles.

For your further information using lower power settings on a microwave does not mean it can be run on lower wattage. The microwave heat is controlled by fewer or more pulses per minute, however each pulse has the same power draw. That is also true for induction power cooking, it too is done with pulses that draw the same power. More frequent pulses are higher power cooking, less frequent are for lower temperature, slow cooking. So on those devices while your power use over time will be less for cooking at the lower temperature settings the size of the inverter needed stays the same no matter what you set the controls on.

But the electric coil type of heating device that is rated for 1,500 watts, the kind where you have a dial to control temperature, could be used on its lower heat settings on your 1,000 watt inverter.

So for that 1,000 watt inverter, electric skillet cooking on low or medium is a yes, but microwave cooking or induction cooktop burner cooking is a resounding no can do. There are two different electrical cooking technologies driving that situation.

 

[Daleford]

Thanks everybody. So I will go with no microwave but be able to use a small fridge, which I just bought. A Danby 150 watt.

 

[Happy Camper]

Microwave ovens do not work well on modified sine wave inverters. They make a lot of noise and opperate at reduced power output. Dorm refrigerators, at least the ones I have, work fine on modified sine wave inverters. I used to use one powered by a 175 watt inverter so a 1000 watt should have no trouble running it.

He has a pure sine wave inverter, gifted by the van gods.

He could run a smaller microwave or inverter microwave at lowered settings easily.

 

[Zerpersande]

You haven’t mentioned what you plan to use as a power source. I never even considered using my car battery.

 

[user 36441]

Anytime you invert 12VDC to 120VAC you are going to have losses. Is it really that important to you to be able to heat something quickly? There are 12V cooking appliances out there, and propane. And a 12V refrigerator will serve you better too. Just something to think about when you can afford it.

 

[Zerpersande]

Anytime you invert 12VDC to 120VAC you are going to have losses….,..

Yep, seems to be around 20%. Not sure on the ballpark figure but it’s high.

There are 12V cooking appliances out there, and propane. And a 12V refrigerator will serve you better too.

Again, agree. My solar system was intended to support lighting, a refrigerator and a limited use air conditioner. All three of which are either 12V or 24V. I have a 24V system and a 24V-12V converter, and that conversion has really low losses.

 

[Daleford]

You haven’t mentioned what you plan to use as a power source. I never even considered using my car battery.

Thanks for asking. I was hoping to use a 100 amp hour deep cycle "golf kart" battery as my secondary. [lead acid] I am a mover, not a sitter, so the vehicle will recharge this battery each day

 

[Daleford]

Anytime you invert 12VDC to 120VAC you are going to have losses. Is it really that important to you to be able to heat something quickly? There are 12V cooking appliances out there, and propane. And a 12V refrigerator will serve you better too. Just something to think about when you can afford it.

You are right. I will give up on the microwave. I just had an older, smaller one here that I was hoping would work, but I will pass on that. I will have propane on board to power a new Camco Wave Catalytic heater so will "T" off and have a small burner stove.

 

[bullfrog !]

Good ventilation is key to reducing condensation which can and is for many a big problem when using unvented propane appliances inside.

 

[Zerpersande]

Thanks for asking. I was hoping to use a 100 amp hour deep cycle "golf kart" battery as my secondary. [lead acid] I am a mover, not a sitter, so the vehicle will recharge this battery each day

I’ve read where some people run into problems when the vehicle’s alternator doesn’t have high enough capacity to charge a second large battery.

 

[maki2]

Thanks everybody. So I will go with no microwave but be able to use a small fridge, which I just bought. A Danby 150 watt.

Sorry to tell you this but return that Danby 150 to the store. What you purchased is not a refrigerator, it is a thermo electric cooler. In hot weather it will not operate at food safe temperatures. It can only lower temperatures to 20 degrees below the air temperature. Food safe temperature is 40 degrees. So add 20 degrees to 40 and you will realize it can not work for food safe storage when it is more than 60 degrees in your vehicle or outside.