Protection circuit for multiple phase power systems

Claim 2

A protection circuit for use with circuit breaker means for electrical apparatus operated by multiple phase, alternating current power systems characterized by a plurality of electrical distribution lines for transmitting electrical energy, the electrical energy in said lines having a spaced phase relationship, wherein said protection circuit comprises: first sensing means coupled to said lines for generating a first signal responsive to detecting an undesirable phase imbalance between two or more of said lines, and detecting a low voltage on one of said lines, and detecting a low voltage on more than one of said lines; second sensing means coupled to said lines for detecting a phase reversal between two or more of said lines, said second sensing means initiating a second signal responsive thereto; circuit breaker operating means coupled to said second sensing means for operating said circuit breaker means responsive to said second signal; time delay means operably coupled between said first sensing means and said circuit breaker operating means, said time delay means for initiating said second signal responsive to said first signal being received for a predetermined period of time; and power selector means coupled to at least two of said lines for supplying a power output from a priority one of said lines to said circuit breaker operating means, with said power selector means selecting another one of said lines responsive to a loss of power on said priority line.

Claim 3

The protection circuit as described in claim 1 wherein said power selector means comprises: third sensing means coupled to said priority line for generating a third signal responsive to detecting an undesirably low voltage thereon and detecting a loss of voltage thereon; and a power selector relay coupled to said third sensing means, to said priority line and to said another one of said lines for selecting as said power output said priority line, and for selecting as said output said another one of said lines responsive to said third signal.

Claim 4

The protection circuit as described in claim 1 wherein said circuit breaker operating means comprises a first relay operating responsive to said second signal, said first relay for coupling said power output of said power selector means to said circuit breaker for activation thereof.

Claim 5

The protection circuit as described in claim 3 wherein said power output of said power selector means is AC power.

Claim 6

The protection circuit as described in claim 3 wherein said power output of said power selector means is coupled to said time delay means for supplying power thereto.

Claim 7

The protection circuit as described in claim 1 further comprising fourth sensing means coupled to at least one of said lines for detecting an over-voltage thereon and for initiating said second signal responsive thereto, said second signal being coupled to said circuit breaker operating means for activation thereof.

Claim 8

The protection circuit as described in claim 6 wherein said circuit breaker operating means further comprises a second relay coupled to said fourth sensing means, and operating responsive to said second signal therefrom for coupling said power output of said power selector means to said circuit breaker means for activation thereof.

Claim 9

The protection circuit as described in claim 6 wherein said time delay means comprises an electrical circuit having adjusting means for varying said predetermined period of time.

Claim 10

The protection circuit as described in claim 1 further comprising first remote control means coupled to said circuit breaker operating means for remotely initiating said second signal thereto, whereby said remote control means may remotely activate said circuit breaker means.

Claim 11

A protection circuit for use with circuit breaker means for electrical apparatus operated by multiple phase, alternating current power systems characterized by a plurality of electrical distribution lines for transmitting electrical energy, the electrical energy in said lines having a spaced phase relationship, wherein said protection circuit comprises: first sensing means coupled to said lines for initiating a first signal responsive to detecting an undesirable phase imbalance between two or more of said lines, and detecting a low voltage on one or more of said lines; second sensing means coupled to said lines for detecting a phase reversal between two or more of said lines, said second sensing means initiating a second signal responsive thereto; circuit breaker operating means coupled to said second sensing means for operating said circuit breaker means responsive to said second signal; time delay means operably coupled between said first sensing means and said circuit breaker operating means, said time delay means for initiating said second signal to said circuit breaker operating means responsive to said first signal being received for a predetermined period of time; over-voltage protecting means coupled to at least one of said lines for detecting an over-voltage thereon and initiating said second signal responsive thereto, said second signal being coupled to said circuit breaker operating means for activation thereof; and power selector means coupled to at least two of said lines for supplying an output of AC power from a priority one of said lines to said circuit breaker operating means, said power selector means selecting said another one of said lines responsive to a loss of AC power on said priority line.

Claim 12

A protection circuit for use with circuit breaker means for electrical apparatus operated by multiple phase, alternating current power systems characterized by a plurality of electrical distribution lines for transmitting electrical energy, the electrical energy in said lines having a spaced phase relationship, wherein said protection circuit comprises: first sensing means coupled to said lines for initiating a first signal responsive to detecting an undesirable phase imbalance between two or more of said lines, and detecting a low voltage on one or more of said lines; second sensing means coupled to said lines for detecting a phase reversal between two or more of said lines, said second sensing means initiating a second signal responsive thereto; circuit breaker operating means coupled to said second sensing means for operating said circuit breaker means responsive to said second signal; time delay means operably coupled between said first sensing means and said circuit breaker operating means, said time delay means for initiating said second signal to said circuit breaker operating means responsive to said first signal being received for a predetermined period of time; over-voltage protecting means coupled to at least one of said lines for detecting an over-voltage thereon and initiating said second signal responsive thereto, said second signal being coupled to said circuit breaker operating means for activation thereof; and power selector means coupled to at least two of said lines for supplying an output of AC power from a priority one of said lines to said circuit breaker operating means, said power selector means selecting said another one of said lines responsive to a loss of AC power on said priority line.