# Behavior of an electric stove on 1-phase vs. 3-phase

I want to replace my current electric stove that's powered by a single phase line with a 20A fuse. I'm in Germany with 230V AC. The overall power that can be delivered is 20A*230V = 4.6kW.

I'm looking at radiant electric stovetops. Some of the new electric stoves I look at come with a power rating of 7kW or even 10kW (oven and top combined). Many can be attached to 1-phase or 3-phase lines. The connector panel on the oven is configured for 1- or 3-phase with metal bridges which connect the three phase terminals in the case of a 1-phase line. Here is a typical schematic where the left side is configured for single phase:

My question is basically: Since the single phase line cannot deliver the 7, let alone 10 kW, the stove must operate differently in a way I don't understand. The stove consists of a number of "consumers" which are essentially independent (the four burners plus oven plus grill). They are probably ohm's resistors (as opposed to induction ovens). My questions are:

• Does the oven start to reduce consumption only when operating several consumers at the same time would exceed the rating (supposedly, it would be limited to pull no more than 20A from single phase)? (Reduction could be by alternatingly switching the burners on and off or by reducing constant output.)
• If yes, how is that achieved?
• Or does it already work with reduced power on a single burner? That would affect all cooking.

The latter would automatically happen if the burners were driven by phase-to phase 400V in the three-phase-configuration but the normal phase-to-neutral in the 1-phase configuration, provided they are essentially ohmic resistors: A burner would never be able to operate at its nominal maximum rating but instead max out at a fraction of it.

But the fact that the three phase connectors are shorted in the 1-phase configuration makes me think that the burners cannot be driven by phase-to-phase power, unless the shorting is detected and reconfigures the wiring.

Essentially, this question boils down to a pragmatic one (how does 1-phase affect my cooking) and a theoretical one (how does the oven work?).