is connected with ground and put in electrical contact with the glass melt in the melting tank application_number US 17996605 A description the first production unit of a float glass production apparatus according to the invention comprises a glass melt producing unit with a melting tank 1 in which a predetermined batch of starting materials is melted in a known way to form the glass to be floated the required melt energy is supplied in a known manner the melting tank 1 is structured in a known manner in the longitudinal direction not shown there is first a feed region for the batch a melt region up to an outlet nozzle or up to a flow through wall in case it is present forms the actual melting vessel which is associated with a so called superstructure in which the gas burner for melting the batch is arranged the connected region between the outlet nozzle and the overflow wall is the refining tank 1 the region between the overflow wall and the flow through unit is the so called refining tank ii an electro additional heating device can be provided in the melting tank or in the refining tank 1 the refining tank and the melting tank form the so called glass melt producing unit the melting tank 1 has a known structure made from fire resistant material which has largely unknown grounds with a similarly unknown high internal resistance as shown from fig1 the fire resistant material of the melting tank 1 has symbolically indicated steel supports 17 which for their part are embedded in the bottom of the melting tank 1 and have a conducting contact to equipotential busbars safety grounds of the apparatus the.