SI20293A - Switching element star-delta - Google Patents

Abstract

Subject of the invention is a switching element star-delta which allows the switching, start-up and operation of asynchronous electric drives and successfully replaces existing switching combinations for controlling electric drives with rated power exceeding 4 kW without limiting its use for any other applications. The design solution of the switching element according to the invention provides three independent positions, which are transmitted via linking elements to the switching part, where a moving flexible contact support by its moving, connects the appropriate terminals thus creating the required electric motor power - star (Y) - with feedback connection to the star point, and after a predetermined period of time the required delta (D) voltage. This is achieved by two magnetic anchors (1) located in the driving section with coils attached by special foil loops (3), and kept at a distance by distance elements (6), which at the same time serve as guides for the common magnetic anchor (2) with cut-out (c), which holds the moving metal support (7), so that the movements of the magnetic anchor (2) are limited.

Description

STAR SWITCH - TRIANGLE

The subject of the invention is a switch element star - triangle, which enables the integration, startup and operation of asynchronous electric motors and successfully replaces the known designs of contactor combinations for controlling asynchronous electric motors with power above 4 kW. The invention generally belongs to the class H 01 H, or. more details in Class H01 H 03/46 of the International Patent Classification.

is A technical problem that the present invention successfully solves is the construction and implementation of such a switching element that will allow the successful replacement of a combination of multiple contactor elements, especially in applications where one element can replace the combination of two or three contactors that are required by the present solutions and form an assembly where the power and control parts between the contactors need to be properly connected to the conductors, otherwise the assembly may be damaged or even destroyed.

Known solutions that solve a technical problem, e.g. Starting and operating electric motors with power above 4 KW, contain three classic contactors and a time relay for switching from star to triangular. In order for the assembly to function properly, the power contacts of all three contactors must be properly connected to each other, which is physically more feasible in the case of higher power sets, since these are larger cross sections of hydrogen.

The design solution of the switching element according to the invention provides three independent positions, which is transmitted through the transmission elements to the contact portion, where the movable carrier of the moving contacts contacts its contacts with its motion and creates the first power supply to the electric motor - star (Y) - with a return connection to the hub and after a certain time the power supply - triangle (D) - which corresponds to the nominal winding voltage of the electric motor, two-stage startup Y - D. The contact system ensures smooth operation and significantly simplifies the classic and contactor combinations by using three contactors and a time relay. The switching time is adjustable and depends on the load driven by the electric motor and the position of the starter signaled.

The switching element of the star - the triangle according to the invention will be explained in more detail on the basis of an embodiment and pictures, of which:

FIG. 1 is a schematic cross-sectional view from the front of the star-switching element of the invention; FIG.

Fig. 2 is a star-switching element according to the invention in cross-section and longitudinal view;

Fig. 3 is a star-switching element of the invention in cross-section and top view;

4 is a star-switching element of the invention in cross-section and side view.

The actuator consists of two permanent magnetic angles 1 and one moving magnetic angles 2. On the permanent magnetic angles 1, coils 4,5 are attached with separate leaf loops io 3, which in the excited state each represent one active position of the switching element according to the invention. Between them, a floating magnetic anchor 2, in the form of a double capital E, floats between them, moving along the lateral metal guides 6, which at the same time allow a suitable distance between the permanent magnetic angles 1. The moving magnetic anchor 2, in the inactive state of the coils 4, 5, it is stationary, which represents the third - off position of the element. The moving magnetic angle 2 transmits force through the steel carrier 7 and the transfer lever 8 to the movable carrier 9 of the moving contacts

10,11,12 in the contact portion of the switching element.

The inlet permanent contacts L1, L2, L3 are mounted on one side 20 of the switching element, and the outlet U1, V1, W1 and U2, V2, W2 on the other, which also corresponds to the markings of the motor terminal board. The contacts are covered by insulating covers 31 with openings for connection wires.

With the active coil 4, the movable carrier 9 moves to position a with contacts 10, 11, 12. The load current from the inlet permanent contacts L1, L2, L3 flows through the moving contacts 11 to the discharge permanent contacts U1, V1, W1 and through the conductors to the windings of the electric motor. The ends of the winding are connected to the permanent contacts U2, V2, W2, where through the moving contacts 10 the hub 13 is formed. The windings of the electric motor are powered by 230 V (Y) and the motor rotor reaches 2/3 of rated speed. When the start-up time expires, the coil 4 becomes inactive and the coil (5) becomes active, which causes the movable carrier 9 to move to position b with contacts 10, 11, 12. This opens the hub 13, and flows through the moving contacts 11,12 and the permanent contacts U1, V1, W1 and U2, V2, W2 into the winding of the electric motor. At this moment, the winding of the electric motor is powered by a voltage of 400 V (D), which is the rated voltage of the winding of the electric motor, the rotor reaches the rated speed and thus is permanently operated.

is The star-triangular switch element is controlled like any conventional contactor, only with the 0-1 switch or via the on-off and on-off buttons of a known remote contact, and mounting is possible on a standard support strip or with screws.

Claims (8)

PATENT APPLICATIONS 1. The switching element of the star - the triangle marked with it. 5 that permanent magnetic angles (1) are mounted in the drive part, on which coils (4,5) are fixed by means of special leaf loops (3), spaced apart from each other by spacer plates (6), which simultaneously serve as a guide for the common magnetic angles (5). 2) with a notch (c) into which the movable metal support (7) is positioned so that the magnetic anchor (2) io is restricted in motion. 2. Star-switching element according to claim 1, characterized in. that the movable metal support (7) is guided vertically in the grooves of the housing (32) and and in the lower part (14) is adapted to insert a round head (15) of the transmission lever (8). 3. Star switch element - triangle according to claims 1 and 2, characterized by. 20 so that, when the coils (4, 5) can be detached from the coils (4), the detachable leaf loops (3) can snap into the thus formed tooth (16) on the coils (4,5). 4. Star switch element - triangle according to claims 1 to 3, characterized in. that the transmission lever (8) is movable by means of a round thickened middle part (17) moving in a semicircular sliding bearing housing 5 (18) and insertable sliding bearing (19), which is firmly fixed with a steel snap ring (20) in the groove of the housing, and the round heads (15,21) on the sides of the transmission lever (8) allow vertical movement of the moving parts and horizontal sliding . io 5. Switching star element - triangle of claims 1 to 4, characterized by. that the contact system has two working and one standstill positions, with three inlet ports (L1, L2, L3) positioned on one side and six outlet connections (U1, V1, W1, U2, V2, W2) on the other 15 of the switching element, such that the double feeder fixed contacts (22) have only one common terminal clip (23) after the phase. 6. Star switch element - triangle according to claims 1 to 5, characterized by. 2 that the movable contacts (11) are clamped between the springs (24) due to the double function, and the hub (13) is mounted in the insulating chamber (25) so as to cover all three phase fields (26), which is made possible by the specially designed movable contacts contacts (10). Ί 7. Star switch element - triangle according to claims 1 to 6, characterized by. that the control of the drive coils on the coils (4, 5) is carried out wired through 5 grooves of the bearing wall (27) into a part of the control elements (28) and the connections (29), while the neutral - off position of the element is provided by the springs (33). 8. Star switching element - triangle according to claims 1 to 7, io characterized by this. that the cover part of the element (30) also secures the lateral cover insulation parts (31) of the fixed contacts (L1, L2, L3) and (U1, V1, W1, U2, V2, W2) with the openings for the power connections that are inserted into the thus prepared grooves (32) of the housing.