A Direct-On-Line (DOL) starter is an electronic 3-phase motor-control system which offers soft starts in DELTA configuration. DOL starters are now replacing the use of manual or semi-automatic "star-delta" starters.
In this way of starting a 3-phase motor, full line voltages are applied to the motor through relays and contactors. The DOL is nowadays the most common type of 3-phase motor starter used.
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 Questions shown below.
There is a link below for the DOL starter circuit.
for smooth operation and also to reduse starting current
Direct on line starter and Heavy direct on line starter...... in HDOL CT is fixed.
Yes up to certain rating and application a motor can be started on DOL. Beyond a rating different methods need to be used to limit the starting current.
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.
A DOL or direct on line starter works by connecting the motor terminals directly to the power supply when they are energized. A DOL starter is the simplest type of motor starter.
The answer is yes. I had seen 110kW pump start on DOL starter
DOL starters are used in industries in-spite of its disadvantages because it is the simplest form of a motor starter. A DOL starter consists of a MCCB or circuit breaker, contactor, and an overload relay that is used for protection.
DOL, Star Delta, Soft starter, VFD
with the help of senser
There is a link below for the DOL starter circuit.
function of dol stater
DOL or Direct On Line is used when referring to induction motor starters. The simplest and most common type of motor starter is the Direct On Line. Some examples where a DOL starter would be used can include water pumps, compressors, conveyor belts and fans. A DOL starter can only be used if the sudden inrush of the motor starting does not cause voltage to drop excessively in the supply circuit.
for smooth operation and also to reduse starting current
DOL, Star Delta, Soft starter, VFD
If the application is high starting torque, then go for star delta or soft starters. If not DOL will do.
Direct on line starter and Heavy direct on line starter...... in HDOL CT is fixed.