Predictive Maintenance from National Field Services 


With the coming summer months – and the higher temperatures and increased electrical loads that go with them – now is a great time to conduct some predictive maintenance (PdM) on your electrical power distribution system. The great thing about predictive maintenance from National Field Services is that we use the latest non-invasive methods – which mean you don’t have to take an outage to check the health of your equipment.

The Problem of Partial Discharge

Do you have older high voltage (HV) or medium voltage (MV) electrical equipment? Has it been properly maintained? Undetected degradation of switchgear insulation can lead to sudden, explosive failures – failures that can shut down your operations and injure your people.

Partial discharge (PD), a localized breakdown in insulation (solid or fluid) under high voltage stress, is a major cause of long-term degradation in HV and MV switchgear. Measuring PD activity is an effective diagnostic tool, allowing you to assess your equipment’s condition and locate the source of the defect, so you can you address the issue with preventive maintenance before complete failure.

Learn about our PD Survey service.


Infrared Surveys

Infrared surveys use the latest thermal imaging technology to measure heat differentials, showing areas on your equipment with high resistance or excessive current flow, indicating problems in the electrical system.

Ultrasonic Detection

High frequency sound waves are generated by partial discharge activity in the early stages of the degradation process if an air path exists from the discharge site to the outside of the equipment. These sound waves can be detected by sophisticated ultrasonic detection equipment in the 40kHz range.

Oil Testing

With non-invasive sampling, oil from your transformers can be withdrawn and sent to a laboratory for chemical analysis, such as oil quality diagnostics and Dissolved Gas Analysis (DGA).

SF6 Gas Analysis

Sampling of the dielectric gas from your high voltage circuit breakers can be analyzed in the field to determine purity, decomposition and moisture content of the gas.

Online Monitoring

Monitors can be installed temporarily or permanently to evaluate various electrical parameters, such as power factor, dissolved gas, partial discharge, dielectric strength and more.

The Power of Predictive Maintenance

Predictive maintenance helps you optimize the performance of your aging equipment and avoid catastrophic outages. National Field Services can design the predictive maintenance program that’s right for you, with non-invasive procedures that are performed while your equipment is on-line. Contact us today!

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