THE SAFETY-RELATED CASE FOR ELECTRICAL MAINTENANCE

The relationship between safety and preventive maintenance is not a difficult one to establish. Properly designed equipment that is properly installed is well capable of doing its job when it is new.

As equipment ages however, several factors begin to take their toll on electrical equipment.

● Dust, dirt, and other contaminants collect on equipment causing the equipment to overheat and bearings and other moving parts to bind.

● Vibration causes hardware to loosen. Subsequent operations of equipment can cause joints and equipment to fail explosively.

● Heat and age can cause insulation to fail, resulting in shock hazards to personnel.

● Increased loads, motor starting surges, and power quality issues such as harmonics combine to increase the aging process and set the stage for equipment failure.

Unfortunately, the ultimate failure of unmaintained equipment usually occurs when the equipment is needed the most—during electrical faults. Such failures result in arc and blast events that can and do harm workers in the area.

They also result in significant downtime, loss of equipment, and construction cost incurred in rebuilding the equipment. The only way to ensure that electrical equipment continues to operate in an optimal manner is to maintain it so that it stays in factory-new-operating condition.

Regulatory
As discussed above and in previous chapters, the catastrophic failure of electrical equipment creates severe hazards for personnel working in the area. Recognizing this the

Standard for Electrical Safety in the Workplace (NFPA 70E)3 requires that electrical equipment be properly maintained to minimize the possibility of failure.

Relationship of Improperly Maintained Electrical Equipment to the Hazards of Electricity

Improperly maintained equipment may expose workers to any of the three electrical hazards. For example:

1. Improperly maintained tools or flexible cord sets (extension cords) can have frayed insulation which exposes the energized conductors and allows them to contact the worker or the metallic tool the worker is using. The result is an electric shock.

2. Improperly maintained protective devices, such as circuit breakers or fuses, can fail when interrupting an overcurrent. Such a failure is likely to be explosive; consequently, the worker is exposed to electrical arc and electrical blast.

3. Improperly maintained connections can overheat resulting in any of the following:
a. melted insulation, exposed conductors, and the attendant electrical shock hazard
b. fire
c. failed connections resulting in electrical arc and blast

4. Improperly maintained switchgear, motor control centers, or panelboards can fail explosively when an arc occurs internally. This exposes workers to the effects of electrical blast and possibly electrical arc.