Apparatus for controlling the starting of a three phase load with its normal phase sequence
First Claim
1. An apparatus for controlling the starting of a three phase load with its normal phase sequence comprising:
- input terminals for receiving a three phase electric energy through external supply lines;
internal supply lines coupled to said terminals for carrying said three phase electric energy to said load;
phase sequence sensing means coupled to said internal supply lines for sensing a phase sequence of the received three phase energy;
phase change-over means connected in said terminal supply lines for reversing the phase sequence of the electric energy supplied to said load when said phase sequence sensing means senses a reverse phase sequence of the received three phase energy;
open phase sensing means having a first circuit connected across the first and second lines of said supply lines for sensing the presence or absence of an open phase in the first and second lines of said internal supply lines and a second circuit connectes across the second and third lines of said internal supply lines and including a time delay means operated by said first circuit, after a predetermined time from the operation of said first circuit thereby enabling said second circuit to detect ther presence of absence of an open phase in any one of said internal supply lines; and
switch means coupled to said open phase sensing means for permitting the starting of said load by said supply lines through said phase change-over means after a predetermined time from the operation of said first circuit when said open phase sensing means detects the absence of an open phase and for inhibiting the starting of said load when said phase sensing means detects the presence of an open phase.
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Accused Products
Abstract
An apparatus for controlling the starting of a three phase load in its normal phase sequence. The apparatus is connected to the load in a predefined manner and has input terminals for receiving three phase electric energy through external supply lines. There is provided a device within the apparatus which automatically corrects the phase sequence of the electric energy supplied to the load. An open phase protection device is provided which allows the starting of the load in response to the absence of open phase in the received electric energy, and inhibits the starting of the load in response to the presence of open phase in the received electric energy due to, for example, breaking of an external supply line. In one embodiment, the apparatus is built into a submersible motor-pump assembly. The pump is always initiated to rotate its impeller in a proper direction for pumping, regardless of correct or incorrect phase connections between the external supply lines and the input terminals of the apparatus. The open phase sensor and associated switches prevent a single phase mode of operation of the load.
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Citations
15 Claims
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1. An apparatus for controlling the starting of a three phase load with its normal phase sequence comprising:
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input terminals for receiving a three phase electric energy through external supply lines; internal supply lines coupled to said terminals for carrying said three phase electric energy to said load; phase sequence sensing means coupled to said internal supply lines for sensing a phase sequence of the received three phase energy; phase change-over means connected in said terminal supply lines for reversing the phase sequence of the electric energy supplied to said load when said phase sequence sensing means senses a reverse phase sequence of the received three phase energy; open phase sensing means having a first circuit connected across the first and second lines of said supply lines for sensing the presence or absence of an open phase in the first and second lines of said internal supply lines and a second circuit connectes across the second and third lines of said internal supply lines and including a time delay means operated by said first circuit, after a predetermined time from the operation of said first circuit thereby enabling said second circuit to detect ther presence of absence of an open phase in any one of said internal supply lines; and switch means coupled to said open phase sensing means for permitting the starting of said load by said supply lines through said phase change-over means after a predetermined time from the operation of said first circuit when said open phase sensing means detects the absence of an open phase and for inhibiting the starting of said load when said phase sensing means detects the presence of an open phase. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification