End-to-End Transformer Care

Cables (below ground)

 

Power cables are often overlooked and misunderstood. They are commonly confused with conductors, which you see coming from the utility into the substation. Cables, on the other hand, are inside of the substation, feeding power to your facility. Most of the cables in use today consist of plastic or rubber dielectric insulation and have already surpassed their 30 – 40 year life expectancy—making preventive maintenance paramount. The cables shown here are below ground and are harder to access for maintenance.

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Failure modes

• Voltage transients

• Damaged semiconducting layers

• Overheating of the cable or insulation

• Insulation cuts

• Incorrect accessory/cable interface dimension

 

Reliability considerations

• Eliminating physical and high load stressors

• IR scanning (visible connectors)

• Offline partial discharge (PD) testing

• Reduction/elimination of overvoltage testing

• Overvoltage monitoring