Electric Boat - Microwave/Convection, Induction Cooktop

This thread seems to be devolving quickly....

Dw,
We recently purchased a 36 Shannon Voyager that does not have a generator and we will not put one in since we will not be anchoring that much.
I have taken out the Force 10 propane stove and am installing a "True Induction" 2 Burner cook top and Samsung Micro/convection ( the door drops down like a oven) as a replacement.
The reason we settled on those brands is that a friend is having a AT built and that is what they are getting.
With the A/C on the induction will not heat the cabin up so much as the propane stove would.
As a backup we will have a Single Burner Butane stove but will most likely never use it.
Bill R.

Bay Pelican said:

Remember, there are many appliances and ac adapters that won't work or will be ruined with a non-pure sine wave inverter. Learned this the hard way.

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Although my Haier 5000but a/c unit works fine on my square (modified) sine wave inverter the microwave would not. I bought a 700 watt Rival -- thinking being the power would not be so big a strain on the inverter. My square wave was 1000 watts continuous/3k surge.

The microwave turntable turned, the clock went down however the sound was "wrong" and the food/water did not heat.

Mine is a digital microwave. I've heard/seen the older dial microwaves work on modified sine wave inverters. Indeed we had one that worked on our 40'er back in the late 70's.

We did burn up a microwave in the 60's -- a $1500 microwave and the inverter did not get along. The next microwave was "only" $400 and they've come down in price a long way since then.

Stepping off Memory Lane...

Bill R. said:

As a backup we will have a Single Burner Butane stove but will most likely never use it.

Click to expand...

Hello Bill. As a side note that may be of use... the camping butane stoves do have an adaptor that will change from the small butane containers to the larger 1 pound green propane bottles. I've got one.

On Amazon they are $22 and if you use any butane at all will quickly pay for itself. It's a sturdy well made unit. Let me find a link for you...




Amazon.com : Kovea LPG Adaptor, Small, Silver : Camping Stove Accessories : Sports & Outdoors

Janice,

Thank you for the info and I had another boat with an inverter and a digital clock would not work on that either but I never thought of a microwave not working.

Thanks,
Bill

Induction cooktops might also be a problem for an inverter.

CaptTom said:

My experience is identical to David's. The run-time is reduced considerably, or sometimes not at all, if we're underway during the day and only stopping overnight. We can go for weeks this way.

I have a 7.5 KW genset but find I have to work hard to load it up. For example, heat water, run the range and battery charger simultaneously. Or run the reverse-cycle heat or AC along with one or two other big loads. We could certainly get by nicely on 3.5 KW.

Obviously, if you find it inconvenient to think about your usage patterns, and just want everything to work at the flip of a switch, you go bigger.

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You, as many do, way over estimate the need to "load up" your generator. Actually, any one of the loads you mention will be just fine for it. You just want some load on it, and avoid no load after a brief warm up or cool down cycle.

I have a 3000 watt 'Peak' inverter MSW, which runs a 1600 watt microwave perfect. It sounds ever so slightly different.

Looks like this one. It runs my LED tv, fluorescent lights, computer, power saws, fridge, fans. But don't run a 16k Cruisair heat pump, it wont work, it might burn it out!
I put a lockout circuit relay on the heat pump, so if inverter comes on, it open the power relay cutting power inline to the heat pump. Makes it sort of dummy proof.
Relay causes a delay, so energy first goes into the solenoid pulling the contacts open.

Mine I bought on ebay for $150.
http://www.amazon.com/Peak-PKC0AW-3000-Watt-Power-Inverter/dp/B0027VT0I8

I have a digital power meter, it reports about 15 amps running the microwave.
Interestingly, the meter says the volts go from 110 vac to 117 vac when running the microwave, so the inverter might boost the power on a bigger load.

I run this into my boats AC power system. I found that it works fine with Leviton and Hubble GFCI with no buzzing. Other GfCI did buzz. I bough new 20 amp Hubbell GFCI, they are good quality on Ebay cheap. I put the inverter output through a GFCI so it makes it much safe, IMO.

So I also opened the inverter, and hard wired, bypassing its output plugs, into a metal box I made having the cutout relay for the heatpump and a GFCI.

Any MSW inverter, you must never ground the neutral, it will either damage the inverter or it will just turn off on overload protection. Some inverters, you can ground the inverters. MSW inverters carry 60 volts ac on each power wire.

Neutral is never a ground anyway in any electrical system except at a generator or grid power, or a distribution panel. Regardless of any type AC system, power always flows on the neutral. My boat panel has no neutral to ground connection, it is like a sub panel, the neutral ground connection is onshore.

My boat gen has the neutral ground bond, but it is disconnected when off on both poles, hots and neutrals, so not a problem with the MSW inverter powered neutral wire.

All disconnecting power sources must on a boat disconnect hots and neutrals anyway, so everyone's boats should already be wired correctly.

caltexflanc said:

You, as many do, way over estimate the need to "load up" your generator. Actually, any one of the loads you mention will be just fine for it. You just want some load on it, and avoid no load after a brief warm up or cool down cycle.

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Of all the old wive's tales (or old men's tales) this just seems to be one of the most common. Don't listen to what John and Joe and Jack and Jill and James and Josh are saying. Listen to and read what the generator manufacturer is saying. No where are any of them ever saying you must keep at 50% or above. Most are targeting 30-70% or so as the ideal target zone and advising to maintain at least 25% or so. 25% vs 50% eliminates a lot of the concern over loads. Also, by increasing the size you're not overloading either. Many who are so concerned about maintaining 50% minimum loads are constantly hitting well above 75% load and regularly hitting 90% load.

Our experience has been that the minimum items we always have on exceed the minimum target load, just things like refrigeration, lights, electronics, and air conditioning plus some galley work push toward the maximum target loads.