DEVICE FOR PROTECTION OF FOUR PARALLEL LINES Russian patent published in 2017 - IPC H02H7/26 H02H3/40 

FIELD: electricity.

SUBSTANCE: device contains a current sensor for each phase of lines, reed switches (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) are used as these phases of lines. For the four homogeneous phases A, B and C, the first (13), second (14) and third (15) identically made units for determining the damaged line, respectively. The inverse input of the first AND element (20) with the inverse input, the first (21) and the second (22) NOT-OR elements are connected to the output of the fifth OR element (16). The direct input of the first AND element (20) with the inverse input, the first (21) and the second (22) NOT-OR elements are connected to the output of the sixth OR element (17). The second NOT-OR element (22) and the sixth AND element (23), the other input of which is connected to the output of the first NOT-OR element (21), are connected to the output of the seventh OR element (18). The input of the seventh AND element (24), the other input of which is connected to the second NOT-OR element (21), is connected to the output of the eighth OR element (19). Outputs of the fifth OR element (16), the first AND element (20) with the inverse input, the sixth (23) and the seventh (24) AND elements are respectively connected to the breaker tripping coils of the first, second, third and fourth lines.

EFFECT: decreased metal capacity of the device.

2 dwg