Is it possible to safely connect European made (for European market) Bosch Induction 2 burner cooktop, 3700w, 220-240v, 50/60Hz in the USA? Cooktop connection diagram comes in 3 wires: brown, blue and green/yellow. Is it safe to connect brown (EU) to black (US), blue (EU) to red (US) and green/yellow (EU) to green (US) or is there a better/safer way to wire it?
First, the US, most countries, and now all countries worldwide have harmonized on safety ground being bare, green, or yellow w/ green stripe. So that's easy. Done.
You will need a letter from Bosch either indicating approval by UL (or some other NRTL) or saying something that will satisfy your AHJ (Authority Having Jurisdiction). This will be required for your permitted work to pass inspection. If you do the work unpermitted, then you are likely to have problems at sale time when the buyer's home inspector spots the alien range and asks questions. It will also be needed to defend your fire insurance should an incident arise which seems related. Consequences for unpermitted work can be severe and have been known to blindside DIYers.
I know the paperwork seems like a lot of nonsense, but state law (NEC) and UL are surrogates for the interests of the fire insurer and mortgage lender. It is, after all, called "Underwriters' Laboratories". However your interests are served also by defining a "bright line" standard for which appliances and work are approved. Convoluted, dragged out, subjective lawsuits are expensive for both sides!
The upshot is that shipping electrical appliances across an ocean (unless it's the Indian Ocean) is usually a bad idea.
As far as the cabling, what's in your walls is a correct and modern 10/3 w/ground intended for a high-end home with a 30A circuit for a cooktop OR oven. (it can't power a combo range-oven typically 40-50A). Ovens need neutral for the oven light. Ranges generally don't need it. Euro ranges definitely don't need it. Simply cap it off and leave it for future use.
However I see a 12/2 NM-B "Romex" cable being used as an extension cord. That's right out. a) it's too small for a 30A circuit, b) it's not cordage (which needs to flex, so must be fine stranded wire), and c) the white wire is not marked to indicate its use as a hot. That marking is especially important around novices, because wouldn't it make sense to attach white to white? If you use black-white-green cordage mark the white wire with red phase tape. Boom, it all makes sense!
The specs indicate that it's compatible with what's common in the USA, specifically 240V, 60Hz.
What you need to do, however, is refer to the installation manual and hook up the two HOT wires to your two service HOT wires and the GROUND connection to the GROUND wire.
Do not rely on colors as these are not guaranteed!
In the USA, the two HOTs for 240V are usually BLACK and RED with the GROUND being GREEN. But ALWAYS check to make sure it's hooked up as you expect.
As far as the appliance colors, you need to check the manufacturers specifications to be sure which wire is which connection.
DO NOT ASSUME ANYTHING!
With the information provided I would say NO. The blue wire is there 240v common it is usually similar to our neutral this being the first NO because our 240v is split each leg has 120v that are out of phase both are hot if this is the case that is a direct short to ground with split 240 power.
The second NO is that a majority of there power is 50Hz jumping the frequency 10hz is a 20% increase can the electronics handle this frequency shift? Remember that induction cooktops are converting the power and coupling it to the cookware to create the heat it’s all electronics and the coils.
If you can provide the mfg and model number we might be able to look up the schematics and because of several different power types in the UL it could be possible but with the information provided I would say NO.
Electrically a 1:1 transformer can convert our split phase to 240v like the system is used and it did say 50/60 so the frequency may be ok. But without verifying that it can safely handle split phase I still would say NO.