Reasons for high pump current

It’s caused by overload; check whether the traffic volume has exceeded the rated value!

The pump was not selected appropriately; the selected head was higher than the actual head, and the selected flow rate was lower than the actual flow rate. If the pump has a return valve, turn it down slightly. This post was last edited by sister on 2009-2-7 23:03.]

Check whether the pump’s bearings are lacking oil or worn out. The outlet valve is open too wide, causing overload. The motor’s no-load current is too high

The load has increased, but I suggest you conduct a mechanical inspection, such as checking the pump’s bearings and mechanical seals. The pressure in the outlet direction is high, causing the motor to overload. It is recommended to increase the diameter of the outlet pipe. The head of the centrifugal pump should not deviate too much below its rated value; otherwise, the flow rate will be too high and overflow may occur. . Check the valve in the pump inlet pipeline for any possibility of blockage, which could cause high resistance at the pump inlet. Excessive resistance can also cause cavitation, damaging the pump impeller. Internal damage to the water pump, such as issues with bearings and seals, leads to increased wear and tear.

Check whether the conveying medium has deteriorated (the current increases as the density of the medium rises)

The wrong pump was selected, resulting in the actual flow rate exceeding the rated value and causing overload; over time this can damage the motor

There may be the following reasons: 1. Damage to the graphite bearing； ⒉The outlet valve is open too wide; close it a bit more ； ⒊Medium issue: the density and viscosity of the conveying medium are higher than the design values. Last edited by Zhongyuanren on 2009-3-2 18:43]

The current is more than 10 times higher than normal; this is definitely not a simple overload situation, and it requires inspection by the manufacturer.

After an overcurrent, the stator heats up, which causes significant damage to the shielded pump. I would like to introduce our company’s Haimitec shielded pumps; it might be useful for you. One of the shielded pumps in our factory has been in operation for 5 years. Last year, it experienced overcurrent and the pump’s casing became hot. We contacted the manufacturer, who said that a major repair was necessary. Since we still needed to use the pump at that time, we had to add cooling water outside the pump casing to lower its temperature, and we continued using it for two months. Before shutdown, no abnormalities were observed apart from heating of the pump body due to overcurrent; after it was shut down and cooled down, the pump could no longer be rotated. It was then sent to the manufacturer for major repairs, and upon disassembling the pump, it was found that the rotor and stator sleeves had stuck together, the graphite bearings were severely worn, and the thrust disc was also heavily worn, which caused a change in its axial position and led to wear on several impellers. The manufacturer states that after 1 or 2 years of operation, the bearings and thrust discs of a shielded pump need to be inspected. If the thrust disc wears out, it can cause the axial position of the impeller to change, leading to friction and an increase in resistance as well as in current flow. Bearing wear can lead to increased vibration, and friction in the impeller can also result in an increase in current. Shielded pumps should be maintained on schedule; one should not wait until they break down before fixing them, as the costs in that case would be very high.

Could it be due to the following reasons: 1. Excessively high rotation speed; 2. Bent pump shaft or misalignment between the pump shaft and the motor shaft; 3. Presence of particles in the medium, resulting in increased mechanical wear and friction within the rotating parts; 4. Excessive flow rate; 5. Overheating or damage to the bearings

The reasons for high current may be as follows: 1. The actual load exceeds the limit, such as low inlet pressure, high outlet pressure, and high flow rate； 2. Low pump efficiency leads to overload, such as excessive ring clearance and severe mechanical wear ； 3. Electrical issues such as three-phase imbalance, faulty ammeters, etc.

A high current means more work is done; in other words, the motor does more work, which results in a higher current

If the flow rate is too high or the pump shaft is bent, try reducing the opening degree of the outlet valve

Support what was said on floor 10: if the current is too high, it is necessary to contact the manufacturer to identify the cause and carry out repairs promptly.

1. Check the condition of the motor. 2. Check the condition of the pump, paying special attention to all the moving and stationary contact points, such as whether the bearings are worn out and whether the balance disk is in good condition. 3. Check the medium in the pump and analyze whether the density has exceeded the limit

One issue is with the selection, the second is that the medium flow rate is too high, and thirdly, there may be mechanical problems with the motor and pump