In the closed pump outlet valve, open the pump inlet valve, and to ensure that the pump "self-irrigation" (liquid level is higher than the pump inlet pipe conditions, the pump starts the program is: start the motor, until the normal operation of the motor, slowly open The outlet valve, so that the current gradually increased, but no one operation (open valve), but also automatically open pump, and the pipe diameter and length (the water quality within the pipeline will be great), such as the motor quickly start, To promote high-quality water acceleration (as the train to quickly accelerate), will make the motor starting current is very large, causing the motor trip and damage to machinery and motor. Using pump soft starter (add a pump soft starter circuit) ----- Slow to increase the speed, you can overcome the above situation, this special control of the motor speed and speed of the soft start is the pump soft starter.
Direct start, the current may reach 6-7 times the rated current, the factory will bring other electrical equipment problems. When Using the pump soft-starter,the start-up current is about 2-3 times of the rated current. For the pump, there are soft stop, so that water slowly fall to eliminate the water hammer effect. Simply said is slowly starting, slowly stopping. This slow time can be adjusted, about 1-60 seconds.
The normal sequence of stopping the pump is: after closing the outlet valve, and then stop the motor, such as no one operation, when the outlet valve is not closed, when the pump suddenly stops, the pipeline of water (especially the vertical pipe), the water will quickly rewind , So when the check valve suddenly closed,
To make the rapid flow of water suddenly stopped by the impact of inertia that is "water hammer" effect and damage the pipeline system,
At this time should be used "soft stop" in the circuit plus soft stop device.
Note: pump soft starter can not avoid the "water hammer" effect occurs.