Motor starter
OwnerOtto J. M. Smithinventor
Life of this patent
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Abstract
An improved method of starting three-phase and three-winding induction motors from a single phase supply reconfigures the 6 accessible windings of a standard induction motor into first an optimal starting configuration which, for example, may reduce starting torque or starting current and then an optimal run configuration. One example of a run configuration is a normal delta along with an inverted delta; another example is a (voltage phasor half-hexagon) run configuration where the windings are all series connected with 120.degree. phase differences.
Claims54
An induction motor with 6 windings wherein 3 of the windings comprise an upright delta connection with three corners and the other 3 windings comprise an inverted delta connection with another three corners, two lines of a single-phase power supply, a first corner of said inverted delta connected to a first corner of said upright delta, a second corner of said upright delta connected to a first line of said supply, a second corner of said inverted delta connected to a second line of said supply, creating the series connection of the upright delta and the inverted delta connected across the two lines of said single-phase power supply, the two external winding corners are the two delta corners not connected together and not connected to the supply lines, one run capacitor connected between one external corner and one line of the power supply, a second run capacitor connected between the other external corner and the other line of the power supply, and during a temporary starting interval, the windings are reconnected in a three-terminal wye which has a wye center, with the power supply lines connected to two of the wye terminals, and a starting capacitor connected between the third wye terminal and the said wye center and including a second starting capacitor connected between said third wye terminal and one of the supply lines.
An induction motor with 6 windings wherein 3 of the windings comprise an upright delta connection with three corners and the other 3 windings comprise an inverted delta connection with another three corners, two lines of a single-phase power supply, a first corner of said inverted delta connected to a first corner of said upright delta, a second corner of said upright delta connected to a first line of said supply, a second corner of said inverted delta connected to a second line of said supply, creating the series connection of the said upright delta and the inverted delta connected across the two lines of said single-phase power supply, the two external winding corners are the two delta corners not connected together and not connected to the supply lines, one run capacitor connected between one external corner and one line of the power supply, a second run capacitor connected between the other external corner and the other line of the power supply, and during a temporary starting interval, the windings are reconnected all in series with 120.degree. phase differences in a four-terminal series circuit, with the terminal designations being in sequence in the series circuit, with the power supply lines connected to the first and third terminals in the series sequence, and a plurality of starting capacitors connected to one winding terminal, one of said starting capacitors connected between the second and fourth terminals in the said series sequence.
An induction motor with 6 windings wherein 3 of the windings comprise an upright delta connection with three corners and the other 3 windings comprise an inverted delta connection with another three corners, two lines of a single-phase power supply, a first corner of said inverted delta connected to a first corner of said upright delta, a second corner of said upright delta connected to a first line of said supply, a second corner of said inverted delta connected to a second line of said supply, creating a series connection of the upright delta and the inverted delta, said series is connected across the two lines of said single-phase power supply, the two external winding corners created are the two delta corners not connected together and not connected to the supply lines, one run capacitor is connected between one said external corner and one supply line, another run capacitor is connected between the other said external corner and the other supply line, and means to temporarily connect and disconnect a starting capacitor between the said external corners.
An induction motor with at least 3 windings, a two-line single-phase power supply, intermittent starting means to connect a delta winding configuration starting connection, one line from said single-phase power supply connected to one corner of said delta, the other line from said single-phase power supply connected to another corner of said delta, a temporarily connected starting capacitor between a third corner of said delta and one of said lines, means for reconnecting the motor windings for a run circuit connection into a series connection of three windings with four terminals 1, 2, 3 and 4 in sequence in the said series, said terminals having a voltage between terminals 1 and 3 which is larger than the voltage between terminals 1 and 2 and larger than the voltage between terminals 2 and 3, a voltage between terminals 2 and 4 larger than the voltage between terminals 2 and 3 and larger than the voltage between terminals 3 and 4, a voltage between terminals 1 and 4 larger than the voltage between terminals 1 and 2, means for connecting said lines to terminals 1 and 3 in said series, and means for connecting a first run capacitor between terminals 1 and 4 in said series, and means for connecting a second run capacitor between terminals 2 and 3 in said series.
A dual-voltage, delta-wound, 3-phase induction motor with 6 windings, a single-phase supply with two lines, a first normal delta connection of three of the windings, a second inverted delta connection of the other three of the windings, connecting one terminal of the normal delta to one of the supply lines, connecting one terminal of the inverted delta to the other supply line, connecting the two deltas in series across the single-phase power supply by connecting a second terminal of the normal delta to a second terminal of the inverted delta, a first means to connect a first run capacitor between the first said one of the power supply lines and the third terminal of the inverted delta, a second means to connect a second run capacitor between the said other supply line and the third terminal of the normal delta, and third means comprising a timer to generate a starting interval of time to temporarily reconnect the windings into a double-wye configuration for the said starting interval consisting of an inverted wye of three of the windings, with a first terminal of the inverted wye connected to one line of said supply, a normal wye with another three of the windings, a first terminal of the normal wye connected to the other line of said supply, and a second terminal of said inverted wye connected to a second terminal of said normal wye to place the two wyes in series across the said supply.
A dual-voltage, delta-wound, three-phase induction motor with 6 windings, a single-phase supply with two lines, two of the windings in series between the said two lines, two additional windings connected in a first parallel branch, with one first branch terminal connected to a first of the said two lines, the last two additional windings connected in a second parallel branch, with one branch terminal of said second branch connected to the said first of the said two lines, a first capacitor connected between the other first branch terminal and the other second branch terminal, and a second capacitor connected between the second of the said two lines and one of the said other branch terminals.
An induction motor with 6 windings wherein 3 of the windings comprise an upright delta connection with three corners and the other 3 windings comprise an inverted delta connection with another three corners, two lines of a single-phase power supply, a plurality of intermittently-connected starting capacitors, a first corner of said inverted delta connected to a first corner of said upright delta, a second corner of said upright delta connected to a first line of said supply, a second corner of said inverted delta connected to a second line of said supply, creating the series connection of the upright delta and the inverted delta connected across the two lines of said single-phase power supply, the two external winding corners are the two delta corners not connected together and not connected to the supply lines, and one of said starting capacitors connected between the said two external winding corners.
An induction motor with at least three windings, a two-line power supply, a plurality of intermittently connected starting capacitors, a series connection of three motor windings with four terminals 1, 2, 3 and 4 in sequence in the said series, one line of said power supply connected to terminal 1, the other line of said power supply connected to terminal 3, said terminals having a voltage between terminals 1 and 3 which is larger than the voltage between terminals 1 and 2 and larger than the voltage between terminals 2 and 3, a voltage between terminals 2 and 4 is larger than the voltage between terminals 1 and 4 larger than the voltage between terminals 1 and 2, and means for connecting one of said starting capacitors between terminals 2 and 4 in said series.
A dual-voltage 3-phase induction motor with 6 windings, a single-phase supply with two lines, a plurality of intermittently-connected starting capacitors, three of the motor windings connected in the phasor form of an inverted wye, with a first terminal of the said inverted wye connected to one line of said supply, three other motor windings connected in the phasor form of a normal wye, a first terminal of the said normal wye connected to the other line of said supply, a second terminal of said inverted wye connected to a second terminal of said normal wye to place the two wyes in series across the said supply, and one of said starting capacitors connected between a third terminal of said inverted wye and a third terminal of said normal wye.
Dependencies are inferred from the claim text.