GB357221A - Apparatus for preventing the withdrawal of current from the mains side of a consumers current meter - Google Patents

Abstract

357,221. Supply meters. FRESCHEVILLE, G. DE, Subotica, Belgrade, Jugoslavia. June 18, 1930, No. 18603. Convention date, June 18, 1929. [Class 37.] The circuit is broken and an alarm given when current is taken from the supply conductors between the meter and the mains. Two electromagnets A, B are connected as shown so that they are normallv in series with each other and with the series winding of the supply meter 3<1> through a switch K. Current supplied to the consumer's circuit P passes through the winding of both electromagnets A, B, which are so arranged that their magnetic fields neutralize one another at the position occupied by an armature m. Current passing through a circuit P<1>, tapped from the mains side of the meter, passes through the winding of the electromagnet A only, causing the armature m to be attached thereto and thereby close the circuit of an electromagnet R. This releases the switch K, which is moved by a spring d, opening the main circuit and closing the circuit of a signal lamp L. The coils of the electromagnets A, B are adjustable axially and the cores are adjustable within the coils, for example by being screwed at their outer ends and provided with nuts. An adjustable spring (not shown) acts on the part carrying the armature m to vary the sensitivity.