Inverter for 4 Ring Induction Domestic Hob?

[brightontrader]

And replaced an old ceramic one that was re-wired (modified by previous owner) to run just one ring off the current 1.5KW Victron pure sine inverter and with a sensor/relay switch to shorepower/generator when on.

I have ditched the sensor/relay set up and just connected the unmodified whirlpool hob to 240 ring main that is either inverter, generator or shorepower powered.

The hob draws a maximum of 7.2kw and has 4 different sized hobs, from small to quite large and I am assuming they draw different amounts of power.?? nothing in manual about this though.

I did this as to be honest, most of the time the boat is in a marina on shorepower so great, full on cooking ability, keeps the wife happy, she gets sea sick anyway..but I do the passages and will inevitably spend time at anchor so am looking now to upgrade inverter. (Generator produces 6.6kw) so I know I will never be able to use all the rings when not connected to SP.

I am looking at larger inverters and they all seem to be charger/ inverters made for solar panel management these days, ie:ZODORE HFV 5000w Peak 15000w Solar Pure Sine Wave Inverter with Charger/built in with 40amp Mppt Solar Charger.

Are these any good for marine use and what are the drawbacks apart from needing a huge battery bank.

When people buy these for boats do they use them as chargers as well, say when on shore power?

Any help appreciated as this is a grey area for me and I don't want to have to run the genny every time I cook as its a noisy one and I have a alternator on the prop shaft anyway.

[AnchorageGuy]

Perhaps if folks knew you are talking about a 4 burner cooktop, you might get more responses. Just a thought. Chuck

[brightontrader]

Is that like ;we say tomato you say tomato?

Fortunately wasn't looking for a lot of replies, one good one will suffice. I did see a number of posts re single "plate" cooktops"...sort of camper van (or RV in your terms) ones but this "cooktop" uses a lot more juice..

Can't edit title now but will know for the future posts to do a translation from my language English to, erhh, what language do you speak again?

Merci, thanks, dzięki and have a nice day

[Sailmonkey]

Huge inverters are readily found as nothing other than inverters. An your different sized rings are in fact different wattages.

Google 5000 watt inverter and you'll find plenty.

I personally think it's nuts to run an electric cooktop on an inverter, but it's technically achievable.


Sent from my iPhone using Cruisers Sailing Forum

[ryon]

Why would you run such a large inverter, and a sine wave inverter at that, just to make heat for cooking? You could damn near cook your dinner with the waste heat from your inverter!

Run an ordinary heating element from D.C. and dispense with the inverter, or better yet, put in a proper CNG stove for a lot less than all those batteries are going to cost and be cooking with gas.

[hellosailor]

In the States, "hob" is variously defined as a particular lacrosse score, a hobgoblin, a shelf in the back of a fireplace, and a machine for cutting gear teeth. No fast mention of anyone using it to refer to a stovetop.


Please bear in mind that after the unpleasantness with George III, the US colonies won the exclusive rights to the English language. The peace treaty only allows you to continue using it if you don't abuse it, otherwise, you'll have to go back to AngloSaxon. Really. It's all in the treaty.

[transmitterdan]

Originally Posted by ryon

Why would you run such a large inverter, and a sine wave inverter at that, just to make heat for cooking? You could damn near cook your dinner with the waste heat from your inverter!

Run an ordinary heating element from D.C. and dispense with the inverter, or better yet, put in a proper CNG stove for a lot less than all those batteries are going to cost and be cooking with gas.

An induction cooktop probably won't work on DC. They are not heating elements. They have inside the stove a converter that changes the AC power to a higher frequency. This frequency is electromagnetically coupled to the "iron" in the bottom of the cooking pot/skillet/whatever. The loss in the iron converts that energy into heat localized at the bottom of the pot. The stove top itself doesn't get hot except for what heat radiates off the bottom of the pot. These are significantly more efficient than resistive heating elements.

[brightontrader]

My strategy for this boat, new to me, is to go all electric and not have gas although my last boat did. There is a large freezer, full size "American" fridge, tower PC, halogen lighting on dimmers and more already on board, plus electric furling....its a juicy boat powerwise.

The sort of thing I am thinking is in for a penny in for a pound. Induction cooktops work really well, better than gas, more efficient. I remember when I sailed in the tropics before with gas the boat got so hot it was ridiculous, I am surprised there is some hostility (not everyone) to these types of cookers on this forum given how good they are..and doing with gas danger potential to boot.

My question really was that do cruisers who use large inverters use the other features, ie: charging, solar panel management etc that these products seem to have? I have seen Mastervolt Dakar 5000 on ebay here and bids end at 5PM GMT, thats why I am asking.

I do appreciate the replies

[skipmac]

It might cost a bit but not a big problem to get enough inverter power to run whatever load you want. The Victron unit allow you to parallel several units to get more power.

The problem is how to power the inverter. A relatively small model of 2000 watts output when you factor in the losses due to inefficiencies will draw close to 200 amps at 12V DC. If you are trying to run several electric hobs (?) and drawing 4-5000 watt one hour of cooking would pull minimum 400 amp hours from a 12V battery bank. You would want to have 1200-1600 amp hour capacity in your battery bank just for that one load.

So first you will need a huge stack of batteries but then, how are you going to recharge them unless you hook up at the dock or run the generator. May as well just run them off the generator to begin with and save a lot of trouble, time, weight, expense, cost and complexity with the battery/inverter setup?

[hellosailor]

Well as long as you are in for a pound and starting from scratch...


Ran across an infomercial for the Wolfgang Puch "pressure oven". This possibly clever gadget is the size of a microwave oven, but uses two conventional electric heating elements (top and bottom) and a lever to pressure seal the oven, like a pressure cooker.


Not cheap at $250-300 (plus rotisserie if you want one) but...doesn't everything look good on tv?(G)

[ryon]

Originally Posted by transmitterdan

An induction cooktop probably won't work on DC. They are not heating elements. They have inside the stove a converter that changes the AC power to a higher frequency. This frequency is electromagnetically coupled to the "iron" in the bottom of the cooking pot/skillet/whatever. The loss in the iron converts that energy into heat localized at the bottom of the pot. The stove top itself doesn't get hot except for what heat radiates off the bottom of the pot. These are significantly more efficient than resistive heating elements.

Right. That's why I don't think inductive is a good idea in this application. It's not efficient, or cheap, to "save" all that energy that he'll be blowing out the inverter fans.

[ryon]

Originally Posted by brightontrader

My strategy for this boat, new to me, is to go all electric and not have gas although my last boat did. There is a large freezer, full size "American" fridge, tower PC, halogen lighting on dimmers and more already on board, plus electric furling....its a juicy boat powerwise.

The sort of thing I am thinking is in for a penny in for a pound. Induction cooktops work really well, better than gas, more efficient. I remember when I sailed in the tropics before with gas the boat got so hot it was ridiculous, I am surprised there is some hostility (not everyone) to these types of cookers on this forum given how good they are..and doing with gas danger potential to boot.

My question really was that do cruisers who use large inverters use the other features, ie: charging, solar panel management etc that these products seem to have? I have seen Mastervolt Dakar 5000 on ebay here and bids end at 5PM GMT, thats why I am asking.

I do appreciate the replies

No hostility. It's just not practical. If you're in the tropics, use any extra electrical capacity to run an AC instead. It will dehumidify as well.

[sea-bee]

Our house is off grid, with about 2000w solar and 400AHr LiFePO4 batteries. On these hot summer days we have excess power, and use a single induction hotplate for quick cooking off the inverter. Draws about 100 amps.

Chris

[StuM]

My 2c worth:

Induction cookers are great when:

a: in a marina on shore power
b: running the genset to top up the batteries, make water, aircon the cabins etc and you have excess AC capacity.

Anything more that short use of a single induction element at lower power settings through an inverter will be hell on your batteries.

[transmitterdan]

Induction cooking is now where near as efficient as propane fire. It isn't even close. You can cook many meals from a single 10kG propane bottle. I doubt you can generate enough electricity from solar to cook more than a meal every few days. You need to do the math on it. Big batteries are only part of the problem. You have to put back more energy into the batteries than you take out else the batteries will be flat dead in a very short time. I sense a generator in your future if you don't have one yet.