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enter image description hereenter image description hereenter image description hereIs 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?

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    Can you post photos of the inside of the junction box you're connecting the cooktop to? – ThreePhaseEel Jan 14 at 12:28
  • Even better, add in a picture of the wiring instructions of the cook top, or an exact model number so they can be found online. – FreeMan Jan 14 at 12:29
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    The fact that it's got a 60Hz rating is a positive sign for "manufactured for worldwide use" as opposed to "strictly European market" design. – Ecnerwal Jan 14 at 13:34
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    @Harper-ReinstateMonica citation needed re: "US appliances aren't insulated for 230V from a hot to ground, and Euro appliances aren't insulated for 120V from a neutral to ground". In my experience in the US, it's hard to even find wire rated for less than 300V (the minimum insulation for 120V would be thin enough that it'd tear too easily I'd think), and every Euro appliance I've seen uses the same type of wire insulation on the neutral wire as they do on the hot. There are certainly other problems with using Euro appliances here, but I don't think wire insulation is usually one of them. – Nate S. Jan 14 at 19:30
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    @Harper-ReinstateMonica, see, that's why I'm not so sure that UL (or whatever testing lab they used) didn't test it in that configuration, since they did approve the instructions saying that 60Hz is fine. Either they're testing it for standard US power (which they do for many devices every day, so a standard test setup) or they'd have to build a special test source of single ended 240V 60Hz, which no one else in the world uses, and I can't imagine why they'd bother to certify something no one will ever use. – Nate S. Jan 14 at 19:45
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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!

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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!

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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.

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    The OP does mention its a 50/60Hz rated cooktop. – user1937198 Jan 14 at 14:39
  • I just caught that after reading the comments and edited. It would now come down to if the electronics are isolated similar to us models. – Ed Beal Jan 14 at 14:44
  • Thanks Ed Beal. I just added additional photos which include model number. There has not been much information I could find in the manual other than what is in the photos. What is the best way to check if the "electronics are isolated" and if they are, should I still be connecting EU brown and blue wires to US black and red wires? – Ari-NYC Jan 14 at 17:26
  • A resistance check or continuity from blue to to ground would show a direct short , the problem can be with solid state electronics that are in different states when powered up, the higher frequencies could be using ground but look open to a DC check I don’t have enough experience with these to feel safe as far as the voltage 220-240 when I was an apprentice we called US split phase 220 and the plug voltage was 110-115 , depending on the local system that may be true today so that in itself is not a good indicator, I will try and look more info up at lunch. – Ed Beal Jan 14 at 17:40
  • From the info I found on UK power the neutral is “earthed” at the sub station. Our neutral is also earthed at the sub station or transformer. We additionally bond it at the service that’s the difference in neutrals both are connected to earth with wire. – Ed Beal Jan 14 at 17:48

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