What’s going on here?
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A new magnetic pump has been installed in our plant’s tank area, with a flow rate of 25, a head of 60, and a motor power of 15. After the pump is started, as soon as the pump outlet valve is opened, the motor trips. The pump is fine as well, and the motor is okay too. What’s going on here? The following figure is the on-site diagram of the pump. The medium is a lactone with a density of about 1.1. Guys, take a look and see why.
From Baidu – is it the situation mentioned in 3.2? 3. Precautions for operating magnetic pump 3.1 The pump must never be operated without a load; if this cannot be ensured, a no-load protection device, a pressure sensor, or a load monitoring device must be installed. Once the fluid supply is interrupted or there is friction inside the pump, the protection device responds by tripping, preventing further damage caused by the pump operating under no load. 3.2 If the motor equipped with the magnetic pump exceeds 7.5 KW, it is advisable to install a slow-start device (such as a star-delta starter). When the motor starts, a high starting torque is generated; if the torque produced by the magnetic stones installed is less than this starting torque, slippage occurs between the inner and outer magnetic stones – that is, the outer rotor rotates while the inner rotor remains stationary. As a result, the eddy current heat cannot be dissipated in time, leading to a sharp increase in temperature. Eventually, this causes the couplings connecting the inner and outer rotors to lose their magnetism, rendering the motor unable to operate.
Hammett’s magnetic pump? How much is the outlet valve open?
Why does this pump look like a temporary setup? Are the inlet and outlet pipes about the same size? If there is no issue with the equipment, the problem might lie in the liquid supply – could it be that the amount of liquid supplied is insufficient?
Is the medium prone to vaporization? If vaporization occurs inside the isolation sleeve, a thrust is generated that moves the rotor in the direction of the inlet. The face thrust bearing will experience dry friction. Superpower
Is the pump outlet valve opened too wide? Does it trip right when it is first opened? What is the motor current when the valve is opened? Does it trip when the valve is only partially opened, or only when it is fully open or at half-open position? Is there any backpressure at the outlet?
The motor tripped due to overload. Check the electrical overload protection setting, verify whether the outlet valve is being operated too quickly, and check if the pipelines are unobstructed
What is the size of the impeller? Is it because the pump’s head is not sufficient?