This case study was written by Neil Williams at Corus Strip Products, and reveals how the All-Test IV Pro 2000 motor tester is used at their Concast plant in Port Talbot.

"I am writing to sing the praises of the All-Test IV Pro 2000 Motor Circuit Analysis (MCA) unit we bought from you recently. It has proven an invaluable aid not just in the diagnosis of motor problems, but also in proving to others that a motor is not the root cause of a plant issue. These are just two examples of the tremendous insight that this unit can give into the condition of motors of virtually any size."

"Within the last few days on our No. 1 Caster, a 225 kW, 3.3 kV 3-phase squirrel cage motor, on a mould water cooling supply system, tripped on I1 / I2 protection in the substation, leaving a vital system without a standby pump."

"Simple electrical checks with a megger and a digital multimeter were performed during the nightshift, but revealed no problems because of the motor size. However, winding resistance readings with a simple multimeter were totally meaningless, so confidence in the motor tests was low."

"As a result, all and sundry declared that the motor was 'burned out' or 'shorted', and would have to be changed. Although we had a spare, the logistics of the swap of a motor of this size would have meant significant plant downtime (and expense). MCA very quickly determined for us that the motor was not at fault, and a problem with the 3.3 kV starter was soon found and rectified. The pump was put back into service shortly thereafter."

"A recent problem with a winch system used to withdraw a dummy bar chain from the No. 2 Strand on Caster 1 was blamed, as always, on the motor - a G.E.C 35 kW wound rotor unit."

"Using this instrument, we benchmarked the motor characteristics by withdrawing a recently refurbished spare from the stores and saving the results. Further checks on the motor in service revealed that there were no issues despite 26 years of service, and subsequent investigative work (made possible because we had proven the motor was good) revealed that the bushes on the ramp rollers were ineffective and acting as brakes, significantly loading the winch motor and causing problems."

"The All-Test IV Pro 2000 has quickly become a formidable weapon in our electrical arsenal, and one which even my mechanical colleagues are beginning to respect, despite the fact that sometimes the results it gives us means more work for them."