Ground fault circuit breaker for protecting low voltage distribution network, has ground fault detection circuit, current sensitivity and action time switches and fault testing switch mounted on circuit board and installed in enclosure

摘要

The breaker has functional components for protecting against surges and against ground fault in a main enclosure (10). The functional components include a zero-phase current transformer (3), a ground fault detection circuit (4), a trip coil, a current sensitivity switch (7), an action time switch (8), and a ground fault testing switch (9). The circuit and switches (7-9) are mounted on a circuit board (20) and installed in the main enclosure. The circuit board is housed in an individual case of a ground fault tripping unit, and placed at a side of an opening/closing actuation handle.