RELAY OF FLUID LEVEL Russian patent published in 1995 - IPC

FIELD: electrical engineering. SUBSTANCE: relay of fluid level has key change-over switches of level and emergency safety change-over switches of heating and overflow having common electric bus with heating safety contact with window where spring element of cantilever type with safety overflow contact is located as well common unit of adjustment contacts with treaded bushing and rod. Bushing presses with one tip against common electric bus with safety overflow contact and threaded rod is pressed against electric bus with safety heating contact. Safety heating change-over switch ensures disconnection of thermal electric heater under emergency conditions when level of water in tank reaches critical value if key change-over switch of level failed to operate. EFFECT: enhanced reliability of control over water level in tanks. 2 dwg