Whirlpool Induction cooktop only half works on inverter

[brightontrader]

Hi, I posted a while back that I was fitting a 4 ring induction and today I tested it on a 1.6kw Victron 24v and to my surprise it :

Made clicking noises, the display went on and off, heated the water but slowly, got the impression that it was half working. Changing the power setting made no difference (having read here that they work by going full power then reducing once heat reaches a certain point seemed to be exactly what was happening.)

The inverter had no trouble delivering power and did not try to shut down on overload, I only tried one ring..at a time, tried all 4, different sizes but they all reacted the same.

Everything I had read on here lead me to believe it would work, maybe it still will by changing something. I have also bought but not installed a 5kw Mastervolt bought on ebay very cheap, was hoping not to install and get away with existing Victron at least to run one ring.

I am well aware that this inverter (if it works) will only drive one ring.

Any suggestions on changes to make this work welcome.

[gamayun]

This may be a silly response, but here goes. It took me a while to figure out that my new, one-burner induction cooktop needed ferromagnetic pans to work...apologies if that is a no-brainer to you.

[TeddyDiver]

Dunno how this particular model works but checkup if it's supposed to have three phase current and might have to be connected differently from a single phase source???

[brightontrader]

Its a domestic induction 220-240v cooktop (hob), so single phase. Very little in the UK is 3 phase outside of industrial machinery needs, and very large yachts/trawlers and the like.

Was very surprised it didn't work given its all within specification. Am contacting Whirlpool about it, and Victron.

[transmitterdan]

What is the full power rating of one cook top ring? The inverter has to be able to drive that with some margin to spare or it will probably never work. Also, is the Victron a pure sine or modified sine inverter?

[brightontrader]

Its a pure sine wave, and the rings are small 2x 1.2kw large 2x2.1kw =7.2 total, output on Phoenix 1.6 is peak 2.5kw. I shut down all other main appliances and batteries were full with 220amps on line across 4xred tops 55s. Small ring should by rights have worked.

Like I said, its a mystery, have emailed Whirlpool in US to see if they have any suggestions.

[transmitterdan]

The large rings will probably never work on a 1.6kW inverter. Is it the small rings that don't work right? Have you measured the AC voltage at the input to the hob when it is "half working"?

[MarkSF]

Have you calculated the losses in the cables between battery and inverter, when you're trying to take 150A or so? What gauge are they?

[BigBeakie]

This will be very interesting to hear what the resolution is. I am considering putting a similar induction unit into a new boat, so will be eagerly awaiting some further news on this.

Thanks for posting on it

[BigBeakie]

My curiosity was piqued by this topic so I called a technician at Bosch to ask what factors may be involved in an induction cooker not working with an inverter.

He identified that the main problem people have patchy results is that the pots are not giving good feedback to the induction coils. The coils sense the quality (iron content) and size of the cookware used, and can give variable results, less power included.

So a common issue is using a pan that is either too big for the coil area or too small. The pan size should match the size of the coil area in order for the coil to properly deliver the full kW capacity.

Also he said to make sure the induction cooker has been properly setup to deliver full power because they can be tweaked to deliver less than full power.

Also if the pot has an aluminium content in the steel, it may not get full power. He said to try the right size cast iron pan or pot on the coil, and if that doesn't fix the problem, and the unit has been setup correctly as per instructions, then start checking exactly what kW is being delivered to the induction cooker. They do not sound like they are very voltage sensitive.

Hope that helps

[transmitterdan]

How does any of that have any relation to an inverter? Presumably the OP has run the cooktop on shore power and all is well. At least I hope that's true.

[BigBeakie]

That's true, it doesn't have anything to do with the inverter, but that's the point of my post.

If the OP has used it at home with the SAME pots successfully, and got different results on the boat, then the search continues for the cause.

But from what I have found out, there is no strange electrical factor to consider. They are very voltage tolerant ( on 240V house supply they work down to 170V) and as long as they are getting enough juice and is setup correctly, it should work.

[transmitterdan]

I would bet that these devices are sensitive to things like source impedance of the power supply. An inverter is a lot different source than the power grid. If it works on shore power but not on the inverter that would not be surprising. The first thing to check is the mains voltage at the hob. If it's low that could be the problem. Another issue is inrush current. At the moment of turn on the inrush current might be higher than the inverter can supply. For shore power this is no big deal. For an inverter with limited current capability it can resulting an endless loop of start, over current, stop, start, over current, stop, ...

[brightontrader]

to all recent replies:

It worked fine on SP, used it with good pans etc, have used induction at home for some time now and am experienced induction cook.....so the pan is not part of the problem..

Whirlpool have unhelpfully come back asking for serial number. receipts etc even though they have model number, need to drive to boat to get these......

Tranmitterdan seems to have hit on what I suspected was happening from the way it clicked and half heated, seemed to be trying to get going, the Inverter though should supply quite a large peak but I was not aware that induction had a start up load...maybe there is one and I just need to to install teh 5kw inverter I bought on ebay after all... was hoping ot re sell it and stick with the 1.6.

I am not sure how easy it is to see with a regular DIY store meter current usage at start up, it maybe the end of me, will wear rubber soled shoes...

[colemj]

Being an inductive load, could it have a low power factor and be outside the inverter capacity?

Mark