Winston Engineering Case Study

Case Study 8 Title: Submersible pump faulty Finding & Observation: Pump is not functioning and has been dismantled by user. Spare parts such as impeller, bearing, mechanical seal, motor coil and O-ring were damaged. Possible Cause Analysis: Damaged parts are generally due to the impeller was stuck with dirt and caused pump motor over-running amp thus burned the motor. Remedy: 1.      All spare parts need to through maintenance periodically by referring to the instruction manual. 2.      Pump condition must be investigated before using. Rectification: 1.      All damaged spare parts have been replaced and advice to the customer about maintenance has been delivered. WINSTON ENGINEERING CORPORATION 1 Joo Koon Way, 628942 Singapore Our mailing address is: marketing@winstonengineering.com.sg

Case Study 8 Incident: Pump running at abnormal high ampere 7.3A Remedy: 1. Remove the submersible pump out of water, place on ground and check the pump rotation. Technician discovered pump was in wrong direction. Swap phase cable and change for correct rotation according to pump casing arrow indication. 2. Place the submersible pump back to pond, check the pump running ampere, 3.7A (same as pump nameplate) Possible Cause Analysis: A centrifugal pump uses a spinning "impeller," which normally has backward-swept blades that directly push water outward. Rectification: 1. During this type of DAB submersible installation, do check and make sure it's in correct rotation. 2. We tend to think that if pump operated in wrong rotation there will be low discharge pressure and low ampere. However, based on this incident, impeller with wrong rotation results in higher discharge pressure (compare to correct rotation) and higher ampere. 3....