Three phase motors usually do not require a neutral point. The core reason is that the winding connection method and the symmetrical characteristics of three-phase AC power work together, so that the neutral point does not have actual current passing through during normal operation, and therefore does not need to be led out.
To understand this, it is necessary to analyze it from three aspects: the basic principles of three-phase electricity, the connection method of motor windings, and the role of the neutral point.

1、 Prerequisite: Symmetrical Characteristics of Three Phase AC Power
Industrial three-phase AC power is a symmetrical three-phase power that meets three key conditions:
The voltage (or current) frequencies of the three phases are the same;
Equal amplitude (voltage/current magnitude);

The phase difference is 120 ° (i.e. phase A leads phase B by 120 °, phase B leads phase C by 120 °, and phase C leads phase A by 120 °).
This symmetry brings an important conclusion: under symmetrical loads, the vector sum of three-phase currents is zero.
It can be expressed mathematically (taking current as an example): i_A+i_B+i_C=0 (when vectors are added, three equal amplitude vectors with a difference of 120 ° will completely cancel each other out)

2、 Core: Two winding connection methods for three-phase motors
There are two standard connection methods for stator windings of three-phase motors: star connection (Y-shaped) and delta connection (△ – shaped).
In both ways, the neutral point either does not exist or there is no current, so there is no need to lead it out.
1. Triangular connection (△ type): There is no neutral point at all
Triangle connection is the process of sequentially connecting the ends of three windings to form a closed “triangle” circuit, with power sources connected to three connection points (A, B, C).

Structurally, the three windings are connected end-to-end without a common connection point, and there is no “neutral point”, so there is no need to lead them out.
Current path: Three phase currents flow through closed triangular windings, with each winding passing through “√ one-third of the line current”, completely relying on the symmetrical characteristics of the three phases to form a circuit without the involvement of the neutral point.
2. Star connection (Y-shaped): The neutral point has no current, so there is no need to lead it out
Star connection is the process of connecting the ends of three windings (usually labeled X, Y, Z) together to form a common connection point – the “neutral point (N)”;

Connect the three terminals (A, B, C) to a three-phase power supply.
Although there is a neutral point in the Y-shaped connection, under symmetrical loads (normally operating motors), no current flows through the neutral point due to the zero sum of three-phase current vectors (i_A+i_B+i_C=0).
At this point, the neutral point is equivalent to an “idle” state and has no practical effect after being introduced (such as not providing single-phase voltage or flowing current).
Therefore, the Y-shaped winding of a three-phase motor usually does not lead out the neutral point, only retaining three phase wire terminals (A, B, C).

3、 Comparison: Why does a three-phase distribution system require a neutral point?
Many people may wonder: “Why doesn’t a motor need a distribution transformer with a Y-shaped connection on the secondary side and a neutral point (forming a three-phase four wire system)?
”The key difference lies in the “singularity” and “diversity” of the load:

A three-phase motor is a single symmetrical three-phase load: during normal operation, the three-phase currents are always symmetrical, and there is no current at the neutral point, so there is no need to draw it out;
Low voltage distribution systems (such as residential/commercial electricity) are multiple mixed loads: in addition to three-phase motors, there are also a large number of single-phase loads (such as lamps, sockets, using only one phase and neutral wire).

The power consumption of these single-phase loads changes at any time, which can cause three-phase current asymmetry (i_A+i_B+i_C ≠ 0), and at this time, the neutral point will generate current (i_N ≠ 0).
The core function of introducing the neutral point (neutral line) is to balance asymmetric loads, ensure stable voltage of each phase, and provide a circuit for single-phase loads.