The motor temperature becomes too high during the individual testing of the centrifugal pump
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Today, during the individual testing of the centrifugal pump, the temperature of the pump’s motor rose very quickly. With an ambient temperature of 30 degrees, the temperature at the motor bearings reached 70 degrees after just over an hour. I’m not sure whether such high temperatures in the motor are normal; it’s my first time conducting tests and I don’t have any experience in this area. The workshop operators also think this is abnormal. I hope experts can tell me whether this situation is normal and what causes the increase in motor temperature.
It’s a bit high. First, check whether enough grease has been applied to the motor, and also observe whether the operating current of the motor is too high. Don’t be afraid; handle problems calmly!
It is necessary to determine whether it is the high temperature of the motor bearing or that of the motor stator windings in order to identify the issue.
It depends on the medium: for our carbon four pump, water is used in the single-stage version. Due to the difference in density, the flow rate generated will decrease accordingly; otherwise, overcurrent can easily occur! I remember that at the outlet of one of the pumps, overcurrent occurred after just 2 amps were applied
Reasons for the rapid increase in motor bearing temperature: 1. Excessive grease applied to the bearings； 2. The motor factory does not conduct thorough inspection before shipment, and the bearings are not installed properly.
How is the alignment of the motor and pump? ~
Check the motor’s temperature rise rate. Will it heat up further after reaching 70 degrees? The key thing to check is whether the temperature continues to rise after reaching a certain level; generally, the temperature increases rapidly at first and then stays constant. There’s no problem with the bearing; keep an eye on it. We have imported motors to check the current; with normal load, everything is fine. During use, the maximum bearing temperature reached 94 degrees; it has been in operation for ten years and is still functioning properly.
As long as the temperature doesn’t rise any further, it’s fine. High temperatures this summer are normal; 70 degrees is acceptable. But as long as it doesn’t keep rising, there’s no problem
A high temperature in the motor bearings may be caused by too much grease being applied； Or the bearing is damaged ； Especially for the motors of newly installed units, due to the long delivery time for these motors, poor protection can lead to water ingress or oil deficiency, resulting in high temperatures
The motor selection is incorrect; motors designed for heavy loads should be used in applications that require light loads. That’s how it is on my end.