FIELD: electrical engineering. SUBSTANCE: invention can be used in electrical installations employing power transformers with capacity up to 100.0 kW and other facilities with water cooling system. Flow relay has body, measuring vessel with hole from which cooling liquid flows out, support-knife. In compliance with invention filled measuring vessel is fixed in left part of lever. Bearing platform with support- knife is fixed in its center part. Platform for contact with contactless inductive pickup is placed on end of right part of lever and mobile counterweight is positioned between bearing platform of lever with support-knife and platform for contact with contactless inductive pickup. EFFECT: enhanced operational stability of flow relay in cooling systems of electrical installations, reduced usage of materials for build-up of cooling systems, their assembly and maintenance, exclusion of requirement for determined value of velocity head in cooling systems of electrical installations. 1 dwg
