Using the Microwave with the Inverter

[Aurora_WA]

I was out crabbing Saturday, and went to go use the Microwave while underway (with the inverter on), and it was acting weird. It would run for 5 seconds and then turn off. I turned off all the other breakers, and it still wouldn't work. When I got back to the dock, and plugged in, the microwave worked fine.

I was wondering if anyone has had the same experience or knew of a solution?

Thanks,
Nick

 

[Dog Islander]

Make sure all the electrical connections at the inverter are clean and tight.

Ray

 

[Osprey]

The suggestion by "Dog Islander" could well be correct. The current drawn by an inverter could be, depending on the microwave design, 100A or more. To maintain the required input voltage to the inverter, very sound connections are necessary. However, another cause may be the problem. It well be that you are overloading the inverter. The inverter can handle the initial start up surge, but shuts down once the continuous power drawn exceeds the maximum continuous inverter power rating. This could be particularly true if you have the optional microwave / convection design. Be aware that the nominal power specification for a microwave oven relates to the output cooking power. The input power is generally much greater. For example a typical 1000W (cooking power) oven will draw 1500 W or more from the electrical supply.
I have a friend with a C26 who has discovered that the above applies to his boat.

 

[wthron]

You may have gotten into a Modified-Sine wave vs Pure-Sine Wave inverter situation in that some electronics do not work well with less sophisticated Modified-Sine Wave inverters as are installed on our Cutwaters. Web search will provide some interesting info.

Below is a very "basic" commentary on the difference:

In short:

Modified-sine-wave inverters are relatively simple and cheap products that generally will use battery power more efficiently than pure-sine-wave inverters.

Only basic products such as normal lights bulbs and induction or shunt motors can safely be run on a modified sine wave.

Pure-sine-wave inverters require many components and therefore come at a higher cost. They produce current that is close to identical to that of grid AC, making them perfect for running sensitive electronics.

If in doubt as to whether your appliances can run on a modified sine wave, always check with the manufacturer.

 

[Aurora_WA]

Thank you all for your responses.

The Microwave is the optional Microwave/Convection that is installed by Cutwater, and the Inverter is standard one installed by Cutwater. (I am a little surprised that this would be an issue with manufacturer installed equipment.) I will check the connections this weekend, but if that is not the issue, is there something I can do to run the microwave without replacing the inverter? (i.e. running at 50% power)

Has any other Cutwater owner had/solved this issue?

Nick

 

[knotflying]

It is my understanding that when you set the power level on the microwave it is actually still giving full power but does it intermittently so that the exposure is the percentage that you set over the period of time. Therefore I suspect that using 50% power will still be blasting full power for half the time on and off and the other half the light is on, the timer is going and the tray spins, but no microwave is blasted.
I think that if you are using the microwave in the convection mode that is where you may be having an issue because besides the microwave going you are also taking power for the heating coil.
Let us know how this progresses for you.

Mike Rizzo