Why does medela breast pump automatically stop sucking?

Medela's automatic default setting is to stop for half an hour without any operation. On the one hand, it is to prevent forgetting to turn it off, on the other hand, too long time will stimulate the nipple too much.

Medela breast pump is a good brand for mothers and workers, and its electric breast pump has many choices. Generally, when the mother chooses the fourth or fifth gear, the effect of breast pumping is very good. It is suggested that the breast pumping time on each side should not be too long, 15 minutes is appropriate, and the longest time should not exceed half an hour. For rich breast milk, you can suck it every three hours.