What is the difference between a star-delta starter and a DOL starter?

Answer 1

At least two types of 3-phase electric motor starter are available: Direct-On-Line (DOL) and Star-Delta.

For more information about how they work, and the differences between them, see the answers to the Related Questions shown below.

Answer 2

DOL starter involves direct switching of polyphase squirrel cage induction motor to supply mains . Star delta starter is based on the principle that 3 windings connected in star, the voltage across each winding is 57.7% of line to line voltage whereas the same winding in delta will have full line to line voltage across each

Answer 3

no

Comment:

With DOL, the full line supply voltage is applied to the motor windings at starting. This is commonly used where the motor is not starting under load or under a heavy load.

Star-Delta,In this case a reduced voltage is applied to the windings at starting and it's achieved since the phase voltage is a quotient Line voltage divided by 1.703. After the motor has attained speed, usually 3 seconds, the full line supply voltage is then applied to the motor windings.

Answer 4

The DOL is nowadays the most common type of 3-phase motor starter used.

A Direct-On-Line (DOL) starter is an electronic 3-phase motor-control system which offers soft starts in DELTA configuration.

In the DOL way of starting a 3-phase motor, full line voltages are applied to the motor through relays and contactors.

It has a "closing circuit" and an "opening circuit". The closing circuit is for applying the service lines to the motor and the opening - or "tripping" - circuit protects the motor by cutting-off (or "tripping") power to the motor from the service lines if there is any overload condition, a single phasing fault, etc.

For more information please see the answers to the Related Question shown below.

Answer 5

A star delta starter brings the motor up to operating speed in two steps. A soft start brings the motor up to speed in multiple steps that can be programmed into the starter. Soft start starters have the option of having a bypass contactor in the circuit so that when the motor comes up to operating speed the bypass contactor pulls in and the soft start is dropped out of the circuit.