Shock protecting circuit breaker for two circuits with common neutral

Claim 2

An electrical protective device comprising: a a casing; b first and second independently operable automatic circuit breakers respectively occupying first and second compartments of said casing, said compartments being of equal width; c each said circuit breaker having associated line terminals for connection to a power source and load terminals; d an externally accessible line neutral terminal for connection to the power source and a second externally accessible load neutral terminal; e a neutral conductor member within said casing interconnecting said line and load neutral terminals; signal generating means for generating a signal related to the algebraic sum of the currents flowing between the line and load terminals of said circuit breakers and through said neutral conductor member, said signal generating means occupying a third compartment of said casing of a width equal to the combined widths of said first and second compartments; g electronic switch means occupying said third compartment and activated in response to a signal from said signal generating means; and h means occupying said third compartment and actuated by said electronic switch for causing automatic opEning of both said circuit breakers; 1 whereby each of said circuit breakers may be connected to a separate load by separate outgoing load conductors connected to said load terminals with the loads sharing a common third conductor connected to said load neutral terminal, and 2 whereby a ground fault occurring in either of the load circuits causes automatic opening of both said circuit breakers.

Claim 3

An electrical protective device as set forth in claim 1 wherein said third compartment is located between said first and second compartments.

Claim 4

An electrical protective device as set forth in claim 1 wherein each of said circuit breakers has a line terminal at one end and a load terminal at the opposite end and wherein said third compartment has said line and load neutral connecting terminals at one end thereof adjacent said load terminals of said circuit breakers.

Claim 5

An electrical protective system comprising: a an enclosure; b at least two main power bus bars supported in insulated relation in said enclosure; c a main neutral connecting terminal supported in said enclosure; d means connecting said main power busbars each to one of two terminals of a source of electric power of predetermined voltage; e means connecting said neutral terminal to a third terminal of said source of electric power having a voltage between it and a first one of said two terminals substantially equal and opposite to the voltage between said third terminal and the other of said two terminals; f an electrical protective device comprising two independently operable electric circuit breakers each connected to a different one of said main power bus bars; g at least two electric power consuming loads located remote from said enclosure; h first and second outgoing load conductors each having one end connected to a different one of said circuit breakers and having its other end connected to a different one of said loads; i a common return conductor having one end connected to both of said loads closely adjacent thereto and having its other end connected to a first neutral connecting terminal of said protective device; j a neutral conductor means connecting said main neutral connecting terminal to a second neutral connecting terminal of said protective device; k a neutral conductor member internally of said protective device connecting said first and second neutral connecting terminals of said device; l said protective device including current unbalance signal generating means for generating a predetermined signal related to the algebraic sum of the currents in both of said circuit breakers and in said neutral conductor member interconnecting said first and second neutral connecting terminals of said protective device; m said protective device also including electrically operable means connected to said current unbalance signal generating means and causing automatic opening of both of said circuit breakers upon generation of said predetermined signal by said current unbalance signal generating means, whereby a ground fault occurring in either of the circuits comprising said two outgoing load conductors, said loads and said common return conductor causes automatic opening of both said circuit breakers; n said electric protective panel assembly including a row of stationary contacts connected in alternating sequence to said power bus bars respectively in a predetermined equal spacing, said circuit breakers of said protective device having connecting terminals spaced apart a distance equal to said predetermined spacing for connection thereto; and o a casing having first and second compartments each containing one of said circuit breakers and a third compartment containing said current unbalance signal generating means and said electrically operable means, said third compartment having a width equal to the combined widths of said first and second compartments.

Claim 6

An electrical protective system comprising: a an enclosure; b at least two main power bus bars supported in insulated relation in said enclosure; c a main neutral connecting terminal supported in said enclosure; d means connecting said main power busbars each to one of two terminals of a source of electric power of predetermined voltage; e means connecting said neutral terminal to a third terminal of said source of electric power having a voltage between it and a first one of said two terminals substantially equal and opposite to the voltage between said third terminal and the other of said two terminals; f an electrical protective device comprising two independently operable electric circuit breakers each connected to a different one of said main power bus bars; g at least two electric power consuming loads located remote from said enclosure; h first and second outgoing load conductors each having one end connected to a different one of said circuit breakers and having its other end connected to a different one of said loads; i a common return conductor having one end connected to both of said loads closely adjacent thereto and having its other end connected to a first neutral connecting terminal of said protective device; j a neutral conductor means connecting said main neutral connecting terminal to a second neutral connecting terminal of said protective device; k a neutral conductor member internally of said protective device connecting said first and second neutral connecting terminals of said device; l said protective device including current unbalance signal generating means for generating a predetermined signal related to the algebraic sum of the currents in both of said circuit breakers and in said neutral conductor member interconnecting said first and second neutral connecting terminals of said protective device; m said protective device also including electrically operable means connected to said current unbalance signal generating means and causing automatic opening of both of said circuit breakers upon generation of said predetermined signal by said current unbalance signal generating means, whereby a ground fault occurring in either of the circuits comprising said two outgoing load conductors, said loads and said common return conductor causes automatic opening of both said circuit breakers; n said electric protective panel assembly including a row of stationary contacts connected in alternating sequence to said power bus bars respectively in a predetermined equal spacing, said circuit breakers of said protective device having connecting terminals spaced apart a distance equal to said predetermined spacing for connection thereto; and o a casing having first and second compartments each containing one of said circuit breakers and a third compartment containing said current unbalance signal generating means and said electrically operable means, said third compartment having a width equal to the combined widths of said first and second compartments.

Claim 7

An electrical protective panel assembly as set forth in claim 4 wherein said thIrd compartment is situated intermediate said first and second compartments.