Correct connection of the windings is the basis for the performance of a three-phase motor. An error leads to incorrect rotation or combustion. Let's look at winding connection diagrams and terminal designations.
Terminal designations
A three-phase motor has six terminals - the beginnings and ends of three windings. According to the modern standard, they are designated:
- Begins: U1, V1, W1
- Ends: U2, V2, W2
On old engines the designation C1–C6 is found.
Star connection
The ends of the windings (U2, V2, W2) are connected to a common point, and to the beginnings (U1, V1, W1) phases are supplied. Used at higher mains voltage.
Triangle connection
The end of one winding is connected to the beginning of the next, forming a closed triangle. Used at lower voltage.
| Scheme | Connection |
|---|---|
| Star (Y) | U2-V2-W2 together, phases on U1,V1,W1 |
| Triangle (Δ) | U1-W2, V1-U2, W1-V2 |
Frequent errors
- Incorrect circuit for a given voltage - overload and combustion.
- Inverted phases - reverse rotation (corrected by swapping two phases).
- Bad contact in the jumpers - phase loss.
If after connection the motor hums, heats up or spins in the wrong direction - check the diagram. If the pins are damaged during rewinding they are restored and re-labeled. A complete check is provided by diagnostics.
Do you need help connecting or repairing an engine in Tashkent? Elektromotors engineers will help - leave a request.