Motor protector device
First Claim
1. A motor protector for monitoring a motor to be protected connected in a circuit for supplying electrical power to said motor comprising a first switch including an actuation means, said first switch connected in said circuit for supplying power to the motor and upon movement of said actuation means, the first switch opening and closing said circuit, a second switch connected in said circuit for supplying power to the motor including an actuation means for opening and closing said circuit and a third switch connected in said circuit for supplying electrical power to said motor including an actuation means for opening and closing said circuit, said actuation means of said first, second and third switches comprising a snap-acting bimetallic member responsive to temperature change each with a selected predetermined first temperature at which it snaps over center and a second lower selected predetermined temperature in which it snaps back to its original state, the selected predetermined first temperature of at least one switch of said first, second and third switches being different from the first selected predetermined temperature of the other switches of the first, second and third switches, and said first, second and third switches maintain said motor and being electrically connected in series.
5 Assignments
0 Petitions
Accused Products
Abstract
A motor protector (1, 1A) for connection in a circuit for supplying electrical power to a motor (36) to be protected includes first (S1), second (S2) and third (S3) switches in a housing member (2, 3). Each switch (S1, S2, S3) uses a snap-acting bimetallic member (8, 11, 13) for opening and closing electrical contacts (4a and 5a, 8a and 8b; 17 and 27; 18 and 30) of the respective switch. The switches (S1, S2, S3) in the housing member (2, 3) are connected as part of the circuit supplying electrical power to the motor (36) being electrically connected in series with one another so that the opening of any one of them will stop the flow of power to the motor (36) to be protected.
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Citations
14 Claims
- 1. A motor protector for monitoring a motor to be protected connected in a circuit for supplying electrical power to said motor comprising a first switch including an actuation means, said first switch connected in said circuit for supplying power to the motor and upon movement of said actuation means, the first switch opening and closing said circuit, a second switch connected in said circuit for supplying power to the motor including an actuation means for opening and closing said circuit and a third switch connected in said circuit for supplying electrical power to said motor including an actuation means for opening and closing said circuit, said actuation means of said first, second and third switches comprising a snap-acting bimetallic member responsive to temperature change each with a selected predetermined first temperature at which it snaps over center and a second lower selected predetermined temperature in which it snaps back to its original state, the selected predetermined first temperature of at least one switch of said first, second and third switches being different from the first selected predetermined temperature of the other switches of the first, second and third switches, and said first, second and third switches maintain said motor and being electrically connected in series.
- 10. A motor protector for monitoring a motor to be protected connected in a circuit for supplying electrical power to said motor compromising a first switch including an actuation means, said first switch connected in said circuit for supplying power to the motor and upon movement of said actuation means, the first switch opening erred closing said circuit, a second switch connected in said circuit for supplying power to the motor including an actuation means for opening and closing said circuit and a third switch connected in said circuit for supplying electrical power to said motor including an actuation means for opening and closing said circuit, said actuation means for said first and second switches comprising a snap-acting bimetallic member responsive to temperature change for opening said circuit and said actuator means for said third switch comprising meltable fuse member responsive to temperature change for opening said circuit, the temperature of actuation of said actuation means of at least one switch of said first, second and third switches being different from the temperature of actuation of said actuation means of said other switches of the first, second and third switches, and said first, second and third switches maintain said motor and being electrically connected in series.
Specification