AC Electric Motor Connection Types

What are the Motor Connection Types? How to Connect the Motors?

Three Phase Single Speed Motors:

Three-phase standard motors terminal plate has 6 connection terminals. Standard three-phase motors can be connected with star or delta method.

Delta Connection                                                                                                                                                           Star Connection 

Three Phase Multi Speed Motors:

Multi-speed motors allow to work at different speeds by changing the magnetic poles without using any frequency converter electronic equipment. Multi-speed motors are categorized in two main groups as having “two separate windings” or “Dahlander winding”. In Dahlander- winding motors, two different speed rating at 2:1 ratio are normally obtained from a single wound motor and combination of winding connection types creates different magnetic poles. 2p-4p, 4p-8p, 6p-12p are common pole combinations. Winding connection and design may vary depending on the application type. Winding connection types according to application types are specified below.


Connection Diagram

Power Ratio (~)

Example Power and Pole Combination

Constant Torque



1.9/3.0kw 8/4p

Constant Power



3.0/3.0kW 8/4p

Variable Torque



0.75/3.0kw 8/4p


In two-separate-winding motors, required speed is obtained with two independent windings with stator. Thus, pole combinations that cannot be achieved with dahlander windings are achieved.Most common seperate winding pole combinations, 2p-6p, 2p-8p, 2p-10p, 2p-12p,4p-6p,4p-12p ve 4p-16p.


Dahlander ∆/YY

∆ Connection – Low Speed                YY Connection – High Speed               ∆ Connection            YY Connection



Dahlander YY/



YY Connection – Low Speed               ∆ Connection – High Speed                 YY Connection            ∆ Connection




Dahlander Y/YY



Y Connection – Low Speed YY Connection – High Speed Y Connection YY Connection




Seperate Winding Y/Y


Y Connection – Low Speed Y Connection – High Speed Y Connection YY Connection




Seperate Winding ∆/


∆ Connection – Low Speed ∆ Connection – High Speed ∆ Connection ∆ Connection


Three Phase Double Voltage Motors:

These motors address different mains voltage needs with using different winding connection types In common use, it is produced with 9 or 12 leads. Sample connection types and label information is given in the table below..


Connection Type

YY Connection

Y Connection

∆ Connection

9 Leads

30kW 460V 60Hz

30kW 230V 60Hz


12 Leads

30kW 460V 60Hz

30kW 230V 60Hz

30kW 400V 60Hz



9 Leads Connection Types:



Y Connection – High Voltage                                                         YY Connection – Low Voltage





12 Leads Connection Types:


Y Connection – High Voltage




YY Connection – Low Voltage





∆ Connection – High Voltage

Single Phase Motors:

Single-phase motors are produced in 2 different model according to the application requirements. QM type single phase motors are with run capacitors and QC type single phase motors are with start and run capacitors. They are manufactured with start-up capacitor and electronic relay or centrifugal switch in applications where high torque is required in the starting operation. The circuit diagram and connection types are given below for both cases.


Run Capacitor                                                             Start and Run Capacitor


Main Windings: U1-U2; Auxilary Windings : Z1-Z2; Run Capacitor: Cd1-Cd2; Start Capacitor:Ck1-Ck2; Supply : L-N