Emergency Power: Protect Equipment and Occupants

Part 1: Emergency-Lighting Systems Give Managers Flexibility

Part 2: Emergency Power: Key Maintenance Practices for Generators

Part 3: Diesel Engines: Common Components of Emergency-Power Systems

Part 4: What are Common Problems with Diesel Engines?

Part 5: Bearing Problems Negatively Impact Emergency-Power Systems

Bearing Problems Negatively Impact Emergency-Power Systems

By Thomas A. Westerkamp - April 2009 - Power & Communication

Generators and motors are key components of facilities’ power systems, and their efficient operation is essential for smooth operation in emergency and non-emergency situations.

Bearing problems are one of the most common maintenance trouble spots with these pieces of equipment.

Several symptoms can occur when bearings or bearing seals become ineffective. Grease or oil from the inside bearing appears outside the housing around the shaft if the outer seal is broken. Noise and vibration, sometimes accompanied by localized heat at the bearing location, occur if technicians overlubricate the bearing or if the races or rollers inside the bearing are deteriorating.

If overgreasing, dirt, or moisture is the problem, the technician can disassemble, clean and repack the bearing with new grease and replace the seal. If, while the bearing is out of the housing, visual inspection shows cracking or fine metal particles, a broken retainer ring or severe rust, technicians can replace the bearing.

When no visual indications appear, another method to detect a bad bearing is to rotate the inner race very slowly with one hand while holding the outer race in the other hand. If a sudden resistance or hitch in the movement occurs, a particle of dirt or possibly a metal cutting has lodged in the clearance between the rollers and races.