Generally speaking, the method of stopping a frequency inverter—or the way it shuts down—refers to how the inverter ceases operation after receiving a stop command. Today, the technical team at Nanjing Oulu Electric will share with you the two stop modes available through the buttons on the inverter panel. Typically, there are two stop methods for frequency inverter buttons:

1. Ramp Stop (deceleration stop)

2. Coast Stop (free stop)

Let’s first take a look at the first stop method: Ramp Stop.
When the Ramp Stop mode is activated by pressing the stop button, the frequency inverter gradually decelerates from its maximum operating frequency down to zero. This process occurs over a predefined deceleration time, during which the frequency decreases smoothly rather than abruptly. By default, most frequency inverters are set to use Ramp Stop.

As shown in Figure (1) of the product manual, the stop mode parameter P6-10 can be configured:

• When P6-10 is set to 0, the inverter uses Ramp Stop (default).

• When P6-10 is set to 1, the stop mode changes to Coast Stop (free stop).

Secondly, what characterizes the Coast Stop mode of a frequency inverter?

When the inverter is running and the stop button is pressed in Coast Stop mode, the output frequency immediately drops to zero, and the operation indicator light turns off. The power output is cut off abruptly. If a motor is connected, it will suddenly lose power while operating at maximum output and will continue to rotate due to inertia. If the load has little inertia, it will stop almost immediately; if the load has significant inertia, the motor will coast to a stop gradually based on its inertia. This mode is typically used for emergency stopping.

That concludes our introduction to the two stop methods available via the inverter buttons. The choice of stopping method depends on the required stopping time in the application. If the required stopping time is shorter than the coasting stop time, braked deceleration stop (Ramp Stop) should be selected.

If you would like further technical exchange regarding frequency inverters, please feel free to contact us. We will arrange a dedicated after-sales service specialist to provide you with detailed one-on-one guidance.