Line break protection for multispeed motor
AssigneeTecumseh Products Company
InventorEmanuel D. Fry
Life of this patent
Estimating the term…
Abstract
Overload protection for a multispeed motor is provided in the form of a plurality of line break motor protectors positioned in good heat transfer relation with the motor windings and having heating elements in circuit with the motor windings to be responsive to excessive winding current and/or excessive winding temperature to disable the windings. Certain of the line break motor protectors are operational in more than one motor speed configuration. The line break motor protectors may be of the self-resetting temperature sensing variety and circuitry is included to insure that the motor does not restart until all protectors are reset subsequent to an overload condition.
Claims22
In a hermetic single phase multiple speed pole changing motor having at least two sections of main winding operable in a selected one of several speed determining pole configurations and at least one auxiliary winding for facilitating start up of the motor, internal overload protection within the hermetic environment comprising:
- a first line break motor protector in circuit with the at least one auxiliary winding and with one main winding section for interrupting current flow through the auxiliary winding and the one main winding section in the event of an overload condition;
- and
- a second line break motor protector in circuit with the other main winding section for interrupting current flow through said other main winding in the event of an overload condition, both said protectors being opertional in more than one pole configuration to respond to corresponding overload conditions and interrupt current flow in their respective windings.
A single phase two speed pole changing motor having two sections of main winding operable in each of two speed determining pole configurations, a pair of auxiliary windings having different pole numbers each for facilitating start up of the motor in the corresponding selected pole configuration, a first line break motor protector operable in either pole configuration to be responsive to an overload condition to interrupt current flow through the selected auxiliary winding and through one of the main winding sections, and a second line break motor protector operable in either pole configuration to be responsive to an overload condition to interrupt current flow through the other main winding section.
Dependencies are inferred from the claim text.