What is the triangle connection of the motor, and the triangle connection of the three phase motor?

Generally, the above motors are triangular connections, and if the direct starting current is large, the step-down start is generally used. Three-phase asynchronous motor is usually set in the winding of two wiring methods, namely star connection (Y) and triangle connection (δ) high-power motors, in each phase winding by two or more branches in parallel. The star connection method is shown in Figure 2, which connects the tail ends of the three-phase system group together, and connects the power supply from the three heads.

Of course, you can also connect the three ends together, and the three ends can be connected to the power supply. However, it is important not to have both a head and a tail end on the shorted star, otherwise the team will not be able to form a normal rotating magnetic field (see Question 1) In the junction box (see diagram) the star point is connected by two connecting pieces.

The triangle connection is shown in Figure 3, which is connected by the first end of one winding and the end of another grid to form a triangle, and then the vertex of the triangle is connected to the power supply. In the same way, with the triangular connection method, the eponymous end of the winding (two head ends or two tail ends) must not be connected to the vertex of the triangle, otherwise, the motor will not be able to operate normally.

A motor, whether it adopts a star joint or an angular joint, must be in accordance with the provisions of the nameplate, and cannot be changed at will. No matter what kind of press method, if the first and last ends are wrong when wiring, after the power is turned on, a normal rotating magnetic field cannot be formed, at this time: it is difficult for the motor to start; There is a special sound; The current in the three-phase winding is very unbalanced, and even if there is no load, the current will be greater than the rated value.

As a result, the temperature rise of the winding increases sharply, and if the power supply is not cut off, the motor winding is in danger of burning out for a long time. Therefore, when using motors, it is very important to connect the windings correctly.

That is, the three groups of windings are connected to each other, AB BC AC means, forming a triangle, commonly known as triangle connection

The triangle connection of three-phase electricity is to connect each phase power supply or load end to end in turn, and lead each connected point out as the three phase wires of three-phase electricity. The triangular connection has no neutral point and cannot lead to a neutral line, so there is only a three-phase three-wire system. When the ground wire is added, it becomes a three-phase four-wire system.

It is named because the wiring is shaped like a triangle.

Motor triangle connection:Because there is no neutral point, the specific method is to connect the head and tail of the three-phase winding of the motor separately, and there is only one voltage level, the line voltage is equal to the phase voltage, and the line current is equal to about a multiple of the phase current. The triangle connection helps to increase the power of the motor, but the disadvantage is that the starting current is large and the winding withstand voltage (380V) is large.

The insulation level has been increased.

The larger power motors are connected into a triangle, and the advantage is that when starting at light load, it is convenient to start with a step-down. The motor with a triangle connection is started by the Y- conversion method when starting at a light load to reduce the starting current.

Star triangle Y series motors below 3KW are star connections 4KW or more are triangle connections with smaller currents and larger voltages Voltage becomes smaller, current becomes larger Star line voltage = phase voltage 3 times the root number Delta line current = 3 times the root number of the phase current torque is small and the torque is large.

Three-phase motor star and triangle two connections are designed to be fixed in the form of connection, can not be changed casually - the star can be made into 3 phases 4 wires, there is a center line can reduce the higher harmonics, mainly for the 3rd harmonic and circulation, and in the case of asymmetric short circuit is safer - if the motor nameplate is marked as a star connection of the motor, if the triangle connection, the voltage and current borne by the windings will exceed the rated value, and the motor windings will be burned - for example, the three-phase 380v star connection is changed to a triangle connection, Its adaptation voltage is three-phase 220V. The triangle connection is changed to the star connection, and the adaptation voltage is 660V - the motor is high-power, in order to avoid the impact of the starting current on the line, the triangle connection is generally changed to the star connection to start, and the triangle connection is converted back to the triangle connection after starting.

The wiring method of the star and triangle of the three-phase motor.

The three phases are: U1--U2, W1--W2v1--v2.The connection method is U1 to W2, W1 to V2, V1 to U2This is the triangular joint. Got it?

The tail and tail are connected === star connection.

End-to-end connection === Corner joint.

The top and bottom are connected to one piece, that is, the upper row 1,2,3 is connected with the lower row 1,2,3. 1 to 1, 2 to 2, 3 to 3Then connect the power supply ABC to 123

The picture above, how can I help you analyze it without a picture!

Three-phase asynchronous motors are divided into two types: star link and angular link.

Star connection: The three ends of the three-phase coil of the motor are connected together as the common end, and the three wires are connected from the three heads. (For example, the A-phase coil is represented by AX, the B-phase coil is represented by BY, and the C-phase coil is represented by CZ, that is, X and Y are connected with Z to lead to three wires of A, B, and C).

Triangular connection: The connection method that connects the beginning of the windings of each phase of the three-phase coil of the motor in turn. (For example, phase A coil is represented by ax, phase B coil is represented by by, and phase C coil is represented by CZ, that is, X is connected to B, Y is connected to C, Z is connected to A, and the three wires drawn out are BX, CY, and AZ).

The three-phase winding of the motor is completely connected to the end cover, there are six heads in the end cover, the three heads below are connected together, and the three heads above are connected with three wires respectively; The upper and lower heads are connected vertically, and the three lines are drawn out separately is a triangular connection.

What is the difference between the star connection and the triangle connection of the motor?

Three-phase electricity. The triangle connection method is to connect each phase power supply or load end to end in turn, and lead out each connected point as the three phase wires of three-phase electricity. There is no neutral point in the triangle joint.

It is also not possible to draw out a neutral wire, so there is only a three-phase three-wire system. When the ground wire is added, it becomes a three-phase four-wire system.

It is named because the wiring is shaped like a triangle.

No matter what kind of press method, if the first and last ends are wrong when wiring, after the power is turned on, a normal rotating magnetic field cannot be formed, at this time: it is difficult for the motor to start; There is a special sound shed answer; The current in the three-phase winding is very unbalanced, and even if there is no load, the current will be greater than the rated value.

Pay attention to the main points

1) Because there is no neutral point in the triangular connection of the motor, the specific method is that the head and tail of the three-phase winding of the motor are connected separately, and there is only one voltage level at this time.

The line voltage is equal to the phase voltage, and the line current is equal to about a multiple of the phase current.

2) Star connection of the motor.

When there is a neutral point (the motor is generally three symmetrical loads, so the neutral wire is generally not drawn), the specific method is that the three tails of the three-phase winding of the motor are connected together, and the three ends are connected to the power supply, at this time, there are two voltage chain levels, namely line voltage and phase voltage, and the line voltage is equal to about multiple of the phase voltage, and the line current is equal to the phase current.

The above internal grinding early appearance reference: Encyclopedia - triangular connection.