Effect of Protective Covers for TEFC Induction Motors Covered by Pulp

Pulp contamination affects motors in the tank area of pulp & paper machines, coating the inter-fin channels, partially blocking the air intake area, and producing motor overheating even for operation below rated condition. This paper reports testing performed that evaluates the benefits of using protective covers to prevent pulp fibers from reaching the inter-fin channels and air intake area. Evaluation is done with a TEFC motor fitted with thermocouples. Results show that as long as direct splashing over the air intake area during washing of the floor with hoses is avoided, protective covers fully protect the motors from the effects of pulp contamination