Problems with centrifugal pumps

The gap is too large, which increases the backflow volume, reduces the pump’s efficiency, and leads to overcurrent

The current may not necessarily exceed the limit, but noise from the pump head will definitely occur.

“Does “angry” mean bigger or excessive? An increased gap in the mouthpiece reduces efficiency and lowers the maximum flow rate and head. In other words, as the gap of the mouth ring increases, the maximum operating flow rate, maximum head, and maximum power consumption decrease, but the specific power consumption (power consumption divided by the product of flow rate and head) increases. If the original maximum operating current does not exceed the limit, overcurrent will not occur due to an increased gap. Of course, under the same working flow conditions, the head will also decrease, and the power consumption will change as well; whether it increases or decreases depends on the changes in head and efficiency. If the original gap of the mouth ring was too small, resulting in friction at the impeller mouth ring, that is a different matter. There are, as it were, no very detailed and authoritative research reports on the impact of slight changes in the gap between the impeller and the pump casing on the current. If it’s just a few millimeters of change caused by equipment aging, it seems that the impact on current shouldn’t be significant. I’m not sure if it’s clear.