Method of using a multimeter to find and connect three-phase asynchronous motors into a triangle
Let's first set each pole phase group. No matter how many poles your motor has, each group of coils has a "head" and a "tail". The definition of "head tail" is that all coils have the same direction according to the direction of the current. After connecting all the machine phase groups in series, there are ultimately six lines left, with each phase having a "head" and a "tail". We define the head of the first term as the number 1, the head of the second term as the number 2, the head of the third term as the number 3, the tail of the first term as the number 4, the tail of the second term as the number 5, and the tail of the third term as the number 6. To ensure a phase difference of 120 degrees, we have swapped the definitions of the beginning and end of the second term
If it is an electric motor below 3KW, we can connect the tails in series and form a star connection. If it is an electric motor above 3KW, we need to connect the tails in parallel first and form a corner connection. The wire sequence of the corner connection is 1 and 6 in parallel, that is, the head of the first item and the tail of the third item are connected in parallel; 2 and 4 are connected in parallel, that is, the head of the second term is connected in parallel with the tail of the first term; 3 and 5 are connected in parallel, that is, the head of the third term is connected in parallel with the tail of the second term. Three groups are connected to three-phase electricity, which is called corner connection. If the motor has a 6-position terminal, as shown in the figure below, connect it with copper foil after wiring according to this definition
Measure three motor phase groups with a multimeter, and the DC resistance values are the same. Find the head and tail according to the above method. The three heads are located on one side inside the motor, and the three tails are located on the opposite side, making it easy to find.
The simplest way is to use the on/off position of a multimeter to measure the six wires between each other. The explanation for continuity is to find the beginning and end of three groups of windings in the same group, with 1 and 2 of the same letter as the beginning and end, and then define the upper end as W2, U2, V2 and the lower end as U1, V1, W1. The order can be referred to in the following figure
