Overcurrent in self-priming centrifugal pumps
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The pump usually operates for only one or two minutes; the water temperature is estimated to be around 40-50 degrees. After it starts and water begins to flow, the current level becomes too high. By opening the flange and pouring in cold water, the current returns to normal levels. Warm water is pumped into the pit on the side; towards the end, the pump casing becomes quite noisy. Could it be due to vaporization? The pump has a relatively simple structure: an impeller along with a secondary impeller (for dynamic sealing); there are no bearings or mechanical seals. An electromagnetic valve is located at the inlet, and a check valve is at the outlet. It’s very easy to rotate the motor
The pump you are referring to is the WFB sealless, automatically controlled self-priming pump, right? The noise that occurs later on, after it was working fine at first, is likely due to cavitation that happens when the liquid level drops.
Cavitation occurs when the liquid level drops; the suction lift of a self-priming pump is very important, and there needs to be a margin
Check if the inlet pipe filter is clogged!
Has it been checked what the setting value for overload protection is? I think this situation is likely due to light-load protection. Have your electrician get the light-load and overload setting values for this pump
1. Beyond the effective suction lift of the self-priming pump (due to temperature) ~~causing cavitation； 2. The overload value is set low; it can be increased appropriately.