LV12800B - Star-to-triangle switching element - Google Patents

Abstract

The invention refers to the star-to-triangle switching element that allows for switch-on, start-up and operation of asynchronous electromotors and successfully replaces the existing versions of contactor combinations for control of asynchronous motors with the power exceeding 4kW, which, however, does not limit its use elsewhere. The constructional concept of the switching element referred to in this invention provides for three independent positions, which is via the transmission elements transmitted into the contact section where the mobile support of flexible contacts with its movement closes the corresponding contacts, which first provides for electromotor power supply - star (Y) - with reverse connection to the star point, and upon the lapse of certain time, for power supply - triangle (D). This is achieved in such a way that the driving element consists of two fixed armatures (1) bearing, attached with special loops (3), the coils (4,5), separated by distance plates (6) that at the same time serve as a guide for the joint armature (2) with the opening (c) wherein fits the mobile metal support (7) in the way that the armature (2) is limited in its movement.

Description

STAR-TO-TRIANGLE SWITCHING ELEMENT

The invention refers to a star-to-triangle switching element that allows for switch-on, start-up and operation of asynchronous electromotors and successfully replaces existing versions of contactor combinations for control of asynchronous motors with 4kW power. In general, the invention is classified into class H 01 H and / or exactly into class H01 H 03/46 of the international patent classification.

The technical problem is successfully solved by the invention in question involving the design and construction of such a switching element that will allow for a successful replacement of a combination of several contactor elements, in particular where one element may replace a combination of two or three contactors such as required in existing solutions and constituting an assembly where the power and control sections between the contactors must be correctly wire-connected unless the assembly may be damaged or even destroyed.

Solving the imposed technical problem, e.g. that of the start up and operation of the electromotors with power output 4 kW, contain three standard contactors and a time switch relay for star-totriangle switching. Correct operation of such an assembly requires the correct wiring of power contacts of all three contacts, which is physically more difficult in assemblies of greater powers that involve wires of larger cross-sections.

The constructional concept of the switching element referred to in this invention provides for three independent positions which are transmitted via the 5 transmission elements to the contact section where the mobile contacts are closed with the corresponding contacts which first provides for the electromotor power supply - star (Y) - with reverse connection to star point, and upon lapse of certain time, power supply - triangle (D) - which corresponds to 10 rated voltage of electromotor winding, double-step start- up Y - D. The contact system provides smooth operation and significantly simplifies the traditional contactor combinations through the use of three contactors and a time-switch relay. The switching time is adjustable and depends on the load driven by the electromotor while the starter position is signalized.

The star-to-triangle switching element, such as that referred to in this invention, will be explained in detail on the basis of the concrete example and the following figures:

Figure 1 A star-to-triangle switching element, such as referred to in this invention, cross-section and front view;

Figure 2 A star-to-triangle switching element, such as referred to in this invention, a cross-section and a longitudinal view;

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Figure 3 A star-to-triangle switching element such as referred to in this invention, a cross-section and a top view;

Figure 4 A star-to-triangle switching element, such as referred to in this invention, a cross-section and a lateral view.

The driving element consists of two fixed armatures 1 and one mobile armature 2. The fixed armatures 1 bear, attached with special loops 3, the coils 4.5, each of them in the make state representing one make state of the switching element referred to in this invention. Suspended between them is armature 2 in the form of letter E; it moves along the lateral metal guides 6 that at the same time provide adequate spacing of the fixed armatures 1. The mobile armature 2 in the break state of the coils 4, 5 is the idle representing the third, off position of the element. The mobile armature 2 transmits force over steel support 7 and over transmission lever 8 to mobile support 9 of the flexible contacts 10, 11, 12 in the contact section of the switching element.

The input fixed contacts L1, L2, L3 are located on one side of the switching element, and the output fixed contacts U1, V1, W1 and U2, V2, W2 are the other side which corresponds to the marking of the electromotor connection plate . The contacts are covered by two insulation covers 31 with openings for connection wires.

In case of coil 4 in make state mobile support 9 bearing contacts 10, 11 12 moves to position a. The load current flows from the input fixed contacts L1, L2, L3 via the mobile contacts 11 to the output fixed contacts U1, V1, W1 and through the wires to the electromotor 5 winding. The ends of the winding are connected to the fixed contacts U2,

V2, W2, where the star-point 13 is closed via mobile contacts 10. The electromotor winding is supplied with a voltage of 230 V (Y) and the motor rotor achieves 2/3 rated rotations. Upon the child of start-up time, coil 4 becomes inactive while coil (5) becomes active and causes 10 mobile support 9 with contacts 10, 11, 12 to move to position b.

Thereby the star-point 13 opens and the current flows through the flexible contacts 11, 12 and permanent contacts U1, V1, W1 and U2, V2, W2 into the electromotor winding. At this point, the electromotor winding is supplied with a 400 V (D) voltage, which is the electromotor winding rated at 15 voltage, the rotor achieves rated rotations and thus provides permanent operation.

The star-to-triangle switching element is controlled as with every conventional contactor, either only with the switch 01 or via the ON / OFF key of the existing remote switch; it can be mounted on a standard carrier strip or 20 fixed with screws.

Claims (6)

Formula of the Invention An element for switching from a star to a triangular connection, characterized in that the drive section comprises two rigid anchors (1) which serve to support the coils (4, 5) secured by special clamps (3) and separated by by means of a plate spacer (6), which at the same time serves to guide a common anchor having an opening (C) in which a movable metallic support enters tightly so that the movement of the anchor (2) is restricted. Element for switching from a star to a triangular connection according to claim 1, characterized in that the movable metal support (7) moves vertically along the grooves of the housing and its lower part is adapted for mounting the round head (8) of the transmission lever (8). 15). Element for switching from a star to a triangular connection according to claims 1 and 2, characterized in that, when assembling the bodies of the coils (4, 5) on the anchor (1), the two removable clamps (3) can be mounted in two corresponding in the teeth of the coils (4 5). Element for switching from star to triangle according to claims 1 to 3, characterized in that the transmission lever (8) is movable by means of a round and thick central part (17), the movement being directed to the inside of a semicircular housing bearing (19) secured by a steel locking ring (20) to the housing groove while the two round heads (15, 21) on the sides of the transmission levers (8) allow vertical movement and horizontal sliding of the moving parts. 5. An element for switching from a star to a triangular circuit according to claims 1 to 4, characterized in that the contact system has two locking states and one breaking position, so that the three input contacts (Lj, l_2, L3) are placed in one and six output contacts (U-V, V-W, W-U, U2, V2 W2) are located on the other side of the switching element such that the rigid. double-line contacts (22) have only one common connection point (23) at each phase. Element for switching from a star to a triangular connection according to claims 1 to 5, characterized in that, due to their dual function, the movable contacts (11) are fixed between the springs (24) and the neutral point (13) of the star connection. inserted into the insulating chamber (25) in such a way as to cover all three phase fields (26) provided, for example, by special shaped movable contacts.