Generally the direct online starter working can be done in two different stages namely dol starter control circuit and dol starter power circuit. Between the mains supply terminals and motor terminals the dol starter main terminals are connected and with the two terminals of the three phase power supply as described in figure 1 the control circuit is energized.
3 Phase Electrical Wiring Diagram Wiring Diagrams
3 phase dol starter connection. Despite this direct connection no harm is done to the motor. The dol starter joints the 3 phase main wiring with the induction motor namely l1 l2 and l3 when the start switch is pressed. A dol starter or direct on line starter or across the line starter is a method of starting of a 3 phase induction motorin dol starter an induction motor is connected directly across its 3 phase supply and the dol starter applies the full line voltage to the motor terminals. I have 24vdc coil 5 amp resistive load on 8 qty connected to my plc card this is smoke extraction system and there are five zone with five different plc installed each zone has eight 3hp fans working in primary and secondary configuration. What is dol starter. In the below dol starter wiring diagram i shown a molded case circuit breaker a magnetic contactor normally open push button normally close push button switch thermal overload relay motor trip indicator and 3 phase motor.
This is the wiring diagram of a dol starter. The r y and b phase are connected through mccb to the contactors. I dol starter wiring connection with start and stop buttons are shown in the above figure 1. Mccb or circuit breaker. In the above three phase dol starter wiring diagram. The contactor has 3 types of contacts.
The contactor has 3 main no contacts known as l1 l2 and l3. And one wiring is called controlling wiring. As the power ratings of our starters are based on 415vac 3 phase it becomes necessary to base starter selection on the full load current of the motor and not the power rating. The 3 phase dol starter wiring diagram is shown below. Three phase dol starter wiring diagram. I am facing problem of operation of dol starter 3 phase 3 hp motor through plc.
When an induction motor is connected to the three phase supply a very large current typically 5 to 8 times the full load current flows through the motor. It is an easiest method for starting up three phase induction motor in which stator windings of the motor are connected directly to the main supply. This means that typically single phase motor current will be at least double that of 3 phase motors of similar power output.
Gallery of 3 Phase Dol Starter Connection
