| 摘要 |
FIELD: electric water heaters. SUBSTANCE: electrode heater has changeable electrode unit which includes tubular $$$-shaped electrodes having contacts of electric plug. Electrode unit is potted with insulating plastic 6, for example, elastic polyethylene; electric contacts of plug are not potted. Inlet metal branch pipe has flange and tail-piece. Threaded flange has two holes for jacks of receptacle. Tail-piece is also provided with thread for securing the heater on water cock by means of nut which expands bush made from elastic material through ring and sectors. Casing located between two flanges has holes where indicator lamps, core and grounding indicator unit are fitted. Interior of casing is potted with compound to have jacks of receptacle insulated from flange. Outlet branch pipe is connected to flange 8 together with electrode unit by means of union nut. Grounding indicator unit contains two indicator neon lamps which are connected in series with ballast resistors and with jacks of receptacles and consequently to tubular and $$$-shaped electrodes through receptacles pins 4 and 5. Center tap between lamps is connected to inlet branch pipe. EFFECT: ease of replacement of worn electrode unit without replacement of heater as a whole; enhanced safety of heater due to availability of ground indicator. |
