To invert or not to invert

[Ed-N-Dani]

Hello everyone, been absent for a little. Have my hands full with a ton of work on the remodel. I ended up going with a standard 115VT mini fridge and thought Id take it to the next step and connect an inverter (if this is possible) to keep it running while we are traveling between home and the CGs etc. I found a fairly inexpensive one on Amazon and according to their specs it will handle a mini fridge.

My question is can I power the inverter right from the 12VT feeding the camper from the trailer plug? Just grab the hot and the common?

Second, what is the best way to switch it between the inverter and a standard 115vt line. I can install the inverter behind the fridge and just access it from the exterior Dometic service door and move the plug from one to the other once we have the standard service connected or should I install a throw switch to switch between power supply's? Does it really matter with the exception of convenience to install a switch?

Thanks!

Ed

Thanks!

Ed

[Ed-N-Dani]

I get all excited to do this then when I read the technical requirements I want to hold off. Thats what I think I'm going to do. Rather then rush into this I'm going to take some time over the winter and learn a little about the solar game and the inverters etc. I feel if I rush into this I'm going to end up with two of everything and or things that wont work for my application.

I hope to find some USA made items for the kit but from what I seen on a simple search online there isn't much of this stuff made in the US. Doesn't surprise me.

Will throw a shout out to Dewalt, I recently learned that they moved 80% of their manufacturing back to the US and working on the last 20%. Would explain how Dewalt lost the end isle space at Homedepot.

Thanks again guy, I'm gonna do some reading and work on this in the spring.

Kindest regards
Ed

[wa8yxm]

Well. Speaking from experience on this
When I pulled a trailer one of the campgrounds I visited regularly (My favorite iun fact) started charging for electricty.. I had been buying ICE, lots of it some months, for the Coolers but since they were charging for Power.. I went to SEARS and came home with a big box (Dorm/office size fridge, or "mini") same as you have, 100 watts it said on the ID label, but a 450 Watt inverter would not kick start it. I now have a 750 that might (I think) but alas, no longer have the fridge, a 1,000 DID (Ok so that was a Genrac Generator). with power left over.

Connecting the inverter to the Battery......

When you break 100 watts you need Big Heavy Wires.. Most of the wiring in an RV can handle 100-200 watts but the voltage drop may cause the inverter to crash (Error out) over 100 watts... 500 watts or more is a serious overload on the existing wiring.

How to fix

Get ye to Auto-Zone, Discount Auto, Store AUTO dept, NAPA, ____ Auto Parts (you fill iun the blank)

And pick up the following
One short RED starter cable
one "T" Fuse and holder, size depends on inverter, about 11 or 12 amps per 100 watts is a good guide line.. Or if the inverter has a DC fuse get the next size up.

A longer RED starter cable
And a BLACK cable

How long the long cables (Red and black) are comes next

ON THE Rv. Find a compartment as close to the batteries as possible but NOT in teh same air space. You do not want the inverter to "Breath" battery fumes.

Find a place to mount the inverter
Now measure for cable length.

Connecting.

Connect Black (negative) and Red (Positive) to the Inverter, Tighten nuts well, Tape the red and black wires side by side together (like lamp cord) till you get to the end of the red, Attach the fuse holder and the short red cable, Connect First red, then Black to battery (Again red to positive)

Turn on inverter and test

Run an extension cord (I like 12ga cords but for a short run and a small 'Fridge 14 shoudl do) to the Fridge.

NOTE: your batteries WILL run down in transit. The tow vehi8cle will NOT charge fast enough.

Note two: 1000 watt iverters the recommended MINIMUM battery is a 4D or a pair of GC-2 Golf car batteries.. Add a 2nd one (or pair) for each thousand watts.

Half the recommended will work, but will run down faster.

[time2roll]

Kit is fine if those are the exact components you need.
Cables etc need to be the right length for example.
1500w inverter? I would go 2000w sine wave or 300w or less for inverters.
Yes I would build my own kit.

[westend]

You can buy the pieces of a similar setup cheaper by the piece than buying that kit or any other kit.
Also, if you want to stick to that "buy USA" mantra, the kit is loaded with Asian products.

[Ed-N-Dani]

Ok, here I go. I'm ahead of schedule on the repairs to the camper so I have the time to revisit the solar/power inverter. Since I did away with the Dometic fridge Id like to get the solar running so we can run the fridge when on the road.

Wanted so feed back on this unit from Amazon.

WindyNation 200 Watt (2pcs 100 Watt) Solar Panel Kit + 1500W Power Inverter + 200ah 12 Volt AGM Deep...

Thanks!

Ed

[BFL13]

We have a 120v 3.2 cu ft fridge in the truck camper. The fridge starts and runs perfectly from the MSW inverter no sweat. Don't need no stinkin PSW! 🙂

It is a big inverter designed to run induction loads though. (Vector 2000w MSW SST)--overkill for the fridge, but it also does the microwave, toaster, and kettle as required.

I gather some smaller watt MSW inverters are not designed to run induction loads, so that might be the difference here, no idea.

[darsben1]

Ed-N-Dani wrote:

darsben1 wrote:

Ed-N-Dani wrote:
OK, thank you. I think I'm going to hold off until next spring to tackle this one. I really dont have the time to do it correctly right now and we only have one trip to take before I put it away for the winter. Ill pick your brains in the spring and use ICE packs for this trip. Its only a 5 hour drive. I freeze it up over night before we leave.

Thanks again

Ed

Or buy some dry ice

I thought about that. We use to have a place in Glassboro NJ that sold it which is only 20 minutes from home.

Thank you

There is a guy in Runnymede

[Ed-N-Dani]

darsben1 wrote:

Ed-N-Dani wrote:
OK, thank you. I think I'm going to hold off until next spring to tackle this one. I really dont have the time to do it correctly right now and we only have one trip to take before I put it away for the winter. Ill pick your brains in the spring and use ICE packs for this trip. Its only a 5 hour drive. I freeze it up over night before we leave.

Thanks again

Ed

Or buy some dry ice

I thought about that. We use to have a place in Glassboro NJ that sold it which is only 20 minutes from home.

Thank you

[darsben1]

Ed-N-Dani wrote:
OK, thank you. I think I'm going to hold off until next spring to tackle this one. I really dont have the time to do it correctly right now and we only have one trip to take before I put it away for the winter. Ill pick your brains in the spring and use ICE packs for this trip. Its only a 5 hour drive. I freeze it up over night before we leave.

Thanks again

Ed

Or buy some dry ice

[DrewE]

You do need the inverter close to the battery. The charge line from your truck may be able to keep up with the running power needs of the fridge, but it is entirely insufficient for the starting surge.

Either moving the plug or installing a DPDT switch as a transfer switch would be safe and workable. You could also leave the fridge connected to the inverter all the time and rely on the converter in the trailer to supply adequate 12V power when plugged in.

You need a pure sine wave inverter that's around 1000 watts or larger to operate the fridge. A typical modified sine wave will not play nicely with the compressor motor, and a smaller one will have trouble with the startup surge.

[Ed-N-Dani]

OK, thank you. I think I'm going to hold off until next spring to tackle this one. I really dont have the time to do it correctly right now and we only have one trip to take before I put it away for the winter. Ill pick your brains in the spring and use ICE packs for this trip. Its only a 5 hour drive. I freeze it up over night before we leave.

Thanks again

Ed

[landyacht318]

While the fridge might only draw 80 watts after the compressor is running, it mght very well require a 1200 watt inverter to handle the start up surge of the compressor.

I'd test the warm fridge on your proposed inverter before expending any more effort wiring it up.

And short and fat cabling is fairly mandatory when wiring an inverter to a battery, even if 10awg can safely pass the 80 watts it might consume after the start up surge

[time2roll]

Surge rating should be 10x the running wattage rating of the fridge.
And I can only recommend sine wave.
Inverter should be close to the battery or the wire size goes up exponentially.
I recommend a small transfer switch to integrate with the 120v power.
15a ts $50

[darsben1]

"My question is can I power the inverter right from the 12VT feeding the camper from the trailer plug? Just grab the hot and the common?"

Depends upon the input power requirements of your inverter, the gauge of wire you have feeding the trailer and what amp fuse/breaker you have on the tow vehicle feeding that line to the camper.