240v cooktop for 120v outlet, a bad idea ?

[DerekShepherd]

I've always been under the impression that a 240v commercial grade induction cooktop wouldn't function if plugged into a 120v outlet. The other day, a friend of mine connected a 120v plug to a 240v cooktop, and surprisingly, it powered on and seemed to work fine on a standard 15A breaker. At 120v, it draws about 10 amps, so in theory, it's within limits. I do understand that 240v is essentially two 120v legs with a neutral and ground, whereas 120v setups have one hot leg, neutral, and ground. my friend said he had an idea of the setup from something he saw online and I know this and a part of me knows isn't how it's supposed to work so I feel weird about it but apart from the increased amp draw, its pretty functional
Is there a real risk of damaging the circuit or causing failure in the long run?

 

[FlipFlopDude]

few factors can shorten the lifespan of a device, and this is one of them

 

[Deleted member 119]

I hope you have enough friends to afford to lose one

 

[PGB1]

Perhaps the reason that the thing works is that it has a Switched-Mode Power Supply. Such devices are very common in items with electronics. The intent is to allow different input voltages, but maintain line wattage among all voltages. (Amps remain the same). Something has to be diminished or sacrificed when the input voltage drops.

Many SMPS devices will "work" far out of the intended range of voltage.

Note that "work" is in quotation marks. While you are happily watching water boil at 120 volts, all mighty heck may be breaking loose inside the device. I'd expect the unit to be deceased soon. Possibly a fire will be included free. Who knows which leg has the protective devices?

Testing-
I did a quick check of a wiring diagram and a schematic for a random Samsung induction cooktop. It certainly will operate at 120 volts due to the SMPS.. However the output from the induction coil will be diminished due to a dampened magnetic field (as compared to connecting at the proper voltage) and the internal components on the circuit boards will run much hotter.