Learn # Direc power system online starter control wiring diagram

From the image you attached, there is a diagram of a Direct-On-Line (DOL) Starter consisting of two main parts: Power Circuit and Control Circuits.

With the following steps:

1. Preparedness (Standby)

• MCCB: When we chop the breaker up, the 3-phase current (L1, L2, L3) will come on top of the contact (KM1).

• At the same time, the current in the control circuit flows through the normal closed (NC) contact of the relay overload (95-96) and the stop button waits at the Start button and the assist contact (Holding Contact 13-14).

2. Startup

• Press the Start button (green): When the Start button is pressed, the current will flow one-stop to the coil of the contactor (Contactor Coil A1-A2).

• Contact Works: When the coil is lit, the steel core pulls the main contacts in the circuit are being connected, resulting in 3-phase electricity flowing through from the MCCB through the contact and through the Overload Relay (OLR) into the motor, so the motor begins to rotate.

• Self-Holding: When the contactor is running, the normal auxiliary contact (NO 13-14) will change the condition to off, allowing electricity to flow through this channel to feed the coil instead. So when we release the finger from the Start button, the motor will continue to operate.

3. Stopping step

• Press the Stop button (red): When this button is pressed, the control circuit will be cut off, leaving no current to feed the coil contactor.

• Functional cut-off contactor: The main contacts are separated, cutting the power transmission to the motor, so the motor stops rotating.

4. Overload Protection

• Overload: If the motor overworks to high heat, Overload Relay (OLR) will detect it.

• Cut the circuit: The normal contact is closed (NC 95-96) in the control circuit will eject (Open), causing the control circuit to be broken. The contact will stop working immediately to prevent motor burns.

• Reset: When correcting the cause, press the Reset button on the OLR to start again.

Brief summary:

1.Press Start\ rightarrow Coil Works\ rightarrow Main Contact Close\ rightarrow Rotary Motor

2.Release Start\ rightarrow light feed through contact help\ rightarrow motor still rotate

3.Press Stop / Born Overload\ rightarrow Coil Stop Work\ rightarrow Main Contact Open\ rightarrow Motor Stop