inverter

[kenk]

Right now I only need power for a 4.5 cu ft fridge and a small microwave. I can get a 2000w pure sine wave for a few dollors more than a 1500w one. do you think the 2000w would be to much over kill?

 

[Bay Pelican]

I found this:
Compact microwaves use between 500 and 800 watts during heating, while a regular sized microwave will use 850 to 1800 watts depending on the model.

My old 4.5 cubic foot refrigerator used 400 watts during the defrost cycle.

Combined the two are at the high end of the power of the smaller inverter.

 

[DavidM]

Are you talking about an inverter with an internal transfer switch which is necessary to switch from shore power to inverter power automatically?

And given the small difference in price that you note, I will bet almost anything that it is one of the cheap Chinese inverters. Caveat emptor.

David

 

[Scratchnsaw]

Make sure you figure in the start up wattage for your microwave, not just the run specs. A typical 800 watt requires 1050 watts to start. But I don't know what size microwave you have.

 

[sdowney717]

Fridge takes more startup power than the MW. 2000 is minimum watts.
I use a 3000 watt inverter MSW, everything runs except my AC on it.

I ran 2/0 wire since I already had some. Round Trip for wire is about 10 feet. Ad I put in a fast acting 500 amp fuse.

 

[boomerang]

We have a 3000W too. It is a sine wave which is a little easier on some appliances and a tad more efficient than the modified inverter of the same wattage. The coffee pot is the real killer for us. The refrigerator is DC only and the microwave we probably could've gotten by with a 2kW easily but like I said, the morning coffee chews up the current!

 

[sdowney717]

Our MW is large and uses about 13 amps all by itself. It uses about the power of the AC Cruisair, but the AC on startup draws maybe 70 amps and the inverter could not do it. Which really I would never do that as it would flatten my 2 house batteries quick, AC needs to run continuously. For AC we have shore or gen power.

 

[CharlieJ]

I have never worked on a boat that reduced its appetite for alternating current.

 

[FF]

"I have never worked on a boat that reduced its appetite for alternating current."

Some cruisers will retrofit LED , DC fans , swamp cooler, car radio, and DC TV and DC or propane reefers to reduce the electrical load.

Some will stick on a solar panel or two to ease the load.

If air cond is not required living with no noisemaker is not difficult.

 

[Bay Pelican]

I have never worked on a boat that reduced its appetite for alternating current.

On Bay Pelican we replaced the Subzero refrigerator and freezer (400 amp hours per day) to Isotherm units (140 amp hours per day) as well as switched the lights to LEDs. Result was we cut the generator run time to less than half of the original time.

 

[FlyWright]

I run a ~4 cu ft fridge, 900W microwave and a fan simultaneously from a 1000W MSW inverter. It works fine.