OVERHAUL OF TWO 90KW CENTRIFUGAL FANS

OVERHAUL OF TWO 90KW CENTRIFUGAL FANS

JJ LOUGHRAN WAS ASKED BY A LOCAL POWER station to assess two 90Kw centrifugal fans. The company’s electrical engineering team attended the site and checked the motors’ insulation resistance, and found that the values recorded were below nominal levels, which would not allow the motors to operate safely.

The extract fans could not be repaired on site, so an engineering team was immediately dispatched to mechanically disconnect both fans from the ductwork, crane them out of position and send them to JJ Loughran’s engineering workshop for an overhaul. Due to the power station’s critical nature, initial inspection and removal were carried out on the same day.

Once in the workshop, the motors were dismantled into individual parts, and each unit was electrically inspected. The mechanical dimensions on the front and back end caps were checked to ensure the values were within machine tolerances. All individual parts were cleaned, rotors and extract fan blades were dynamically balanced, and the bearings were replaced.

The motors were then reassembled and tested before the units were delivered back to the site and were mechanically and electrically reinstalled, run and tested.

JJ Loughran made a recommendation that 230VAC heaters be fitted into the motor windings. Because the fans do not run constantly, these heaters would be energised when the motor is not in use, ensuring dampness or condensation buildup does not occur within the stators.

www.jjloughran.com