Pipeline Pump Motor Overload and Hot Bearings: Causes and Fixes

The motor trips or draws too much current

• Flow far above the rated range because the system head is lower than planned: throttle the discharge valve or choose a trimmed impeller
• Liquid much heavier than water: the motor must be sized for the real density
• Supply voltage too low
• Mechanical damage in the pump or motor

The bearings run hot

• Bearing worn or damaged: replace
• Grease too little, or too much. Grease-packed bearings are filled to about two-thirds to three-quarters; overfilling makes them run hot
• Dirty or wrong lubricant: replace it
• Bent shaft or poor alignment: straighten or realign

Bearings normally run at around 60 °C. If they climb well above that, stop and find the cause before damage spreads.