Electrically insulated bearings increase reliability for a large flue gas recirculation fan
The challenge

A major international producer of heavy duty carton-board was experiencing high maintenance and repair costs related to their large flue gas recirculation fan. These costs were the result of premature bearing failures caused by stray electric currents introduced into the bearings by the variable frequency converter.
The bearings in the boiler’s hot gas fan motor lasted only six months on an average. A solution was needed to eliminate the damaging electric currents, improve reliability and reduce maintenance and repair costs.