How do you wire a star delta motor?

This answer has been temporarily closed to changes because so many askers have been repeatedly splitting-off variants of the question such as "Can you give me simple diagram for star-delta starter".

Please note: diagrams cannot be included in answers.

The answer given includes plenty of details for anyone to be able produce a simple diagram showing how a 3-phase motor can be wired in star and delta configurations.

Answer

To be able to wire a 3-phase motor either in star or delta, all 6 ends of the three sets of coils, called "windings", have to be exposed with suitable connection terminals.

The windings are often labelled A1, A2, A3 and B1, B2, B3, where "1", "2" and "3" denote the separate phase windings and "A" and "B" denote the beginning and end of each winding.

Another way of describing it is to say that the separate windings can be labelled:
Winding 1: A1 <---> B1. Winding 2: A2 <---> B2, Winding 3: A3 <---> B3.

In star configuration either all the A's or all the B's are connected together and the 3-phase supply (consisting of three separate "phase lines" labelled L1, L2, L3) is connected to the remaining three connectors. For example, if you connect B1 to B2 and B2 to B3 to form the center of the "star" then you must connect supply L1 to A1; supply L2 to A2 and supply L3 to A3.

In delta configuration, connect B1 to A2, B2 to A3, B3 to A1. (If you draw that out as a schematic diagram, it will be a triangle.) Then connect supply L1 to A1; supply L2 to A2 and supply L3 to A3. (Exactly the same as the supply lines were connected before, for the star configuration.)

The initial making of those connections in "star" - and subsequent changing into "delta" after the motor has built-up sufficient speed - would all normally be handled by a "star-delta motor starter" unit. A good tip: before you ever start hooking one up, study its schematic wiring diagram carefully to be sure you really understand which of its terminals connect to which motor terminals, and where to connect each line of the 3-phase service cable.

Note:
Some 3-phase motors use an alternative way of labelling the windings: 1A, 1B, 1C and 2A, 2B, 2C.

Electronic motor-control systems, which offer soft-starts in DELTA configuration, are now replacing the use of manual or semi-automatic star-delta starters.

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As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.

Before you do any work yourself,
on electrical circuits, equipment or appliances,
always use a test meter to ensure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.