Abrupt failure of submersible pump motor

<p>I was busy watering the garden one afternoon when the motor driving the submersible pump all of a sudden failed with the red and flashing yellow lights on the control unit switching on. The pump motor was a Brisan 4"GG 2,2 kW single phase motor, supp**** by DAB Pumps South Africa to TPD whom we bought it from. The control unit was not busy starting or stopping the pump at that point. The pump was running when it stopped abruptly.</p> <p>The red and yellow lights on the control unit indicated ‘over current'. I enquired what to do next and the advice I got was to reset everything and then try to start it again. I tried, via the control unit, but it did not start, so we dismantled the pump and motor to take it back to the agents we bought it from. Having removed the installation from the river we turned the spindle of the pump with our fingers to make sure that nothing was caught up in the pump, which could have prevented it from turning, causing the over current.</p> <p>What intrigues me is that the motor did not fail when I tried to start or stop it. It failed while it was busy operating? In addition, after it had been repaired we installed it again using the same irrigation computer and control unit, without changing anything to the installation. Since then the motor and pump have been operating faultlessly. It has been irrigating the garden every second day since early March 2017.</p> <p>My impression therefore is that something must have failed while it was operating. I protected it in every possible manner, including with a control unit supp**** by a ‘reputable’ company, all of which was operational at the time of failure, and in spite of that it still failed? I do not know what more I could have done to prevent operational non-conformance or human interference from causing harm?</p> <p>The DAB diagnostic report states:</p> <p> </p> <p>‘With the investigation of the unit it was found that motor tested down to earth. The windings</p> <p>were checked and tested and it was found that the windings are got damaged. With the</p> <p>measurements of the windings it indicated that the start windings have burnt. The auxi****y coil or</p> <p>stating burns out is normally caused by the non-opening of the stationary switch set where this coil</p> <p>remains switched on longer that the specified time. A locked rotor condition can also cause this type</p> <p>of failure. This type of failure is not covered under warranty’.</p> <p> </p> <p>This could, however, not have been the cause of the damage, because it failed while pumping and not when it was being started. In addition, since it has been repaired it has been operating faultlessly using exactly the same control instrumentation. Every second day the irrigation computer triggers a start-up, which is controlled by the control unit.</p> <p>The DAB diagnostic report is therefore either misrepresenting the real cause of the failure, or, I suppose, the pump motor could have been damaged further while trying to start it immediately after its failure? I or my representative was unfortunately not present when the motor was stripped to observe and judge the cause of its failure?</p> <p>Although this pump and motor was purchased from TPD Pumps it was supp**** by DAB Pumps South Africa to TPD for sale. According to TPD they ‘do not hold the warranty, the importer and manufacturer does for a factory fault’. </p> <p>In my mind this pump motor failed within the warranty period and should, therefore, be replaced by the manufacturer or distributor, in this case DAB Pumps South Africa. However, they flatly refuse. Their Mr John O’Connel suggested that, if I am not satisfied with their reaction I get third party opinions, which I am trying to do here.</p>