Partial Discharge Testing: Costs Versus Benefits

If you are running high value and high voltage electrical installations for your commercial or industrial installations, one of the things that you should consider investing in is partial discharge testing or PD testing. This is a preventive measure that will unearth potential hazards in your installations before any disastrous consequences arise from these.

PD testing is an important investment for your plant. It is no secret that if you are running a high value plant, then electrical installations will be amongst the most valuable assets in your installations. A downtime, even for a few hours, will severely affect your business bottomlines and result in catastrophic financial losses.

When operating your electrical systems at higher levels, you will have to grapple with the long-term reliability of electrical systems – including problems with partial electrical discharge. But what is partial discharge in the first place?

Before you embark into the merits of PD testing, it is important to understand what this electrical fault entails. After all, PD might occur over many years without you even realizing it.

Partial Discharge (PD)

PD occurs when your electrical insulations break down due to high or medium electrical voltage stresses. PD can be catastrophic because once the breakdown in the insulation has been initiated, the deterioration will be progressive and over time, will hit the critical point that leads to electrical disasters. This can result in million-dollar losses for your business and even loss of life.

It is partial discharge because these discharges, due to the breakdown in the insulation, occur only partially.  Usually, these last over nanoseconds or microseconds.  In the initial stages, the PD will be initiated as voids in solid insulation or bubbles where there is liquid insulation.

When these initial breakdowns increase, the PD will acquire a more sinister character – thus leading to those electrical disasters. It is important to take preventive measures and insurance against these kinds of disasters by investing in professional PD testing services.

There are numerous benefits of PD testing services for your plant installations.

Partial discharge testing is basically a predictive maintenance procedure and modern computerized testing methods can capture these waveforms with a great deal of accuracy. This will help your plants forestall future electrical disasters. Partial discharge monitoring and partial discharge measurement are usually done with the help of high-speed wideband oscilloscopes and acoustic detectors.

These can record the PD data over a duration of time. This data is then used in partial discharge analysis, which will assist the engineers in assessing the location, the frequency, the size, and the type of partial discharges.

Through these measurements, it is possible to establish the seriousness of a particular discharge and put in mitigating measures that will prevent this from evolving into a potential disaster. The PD engineers will give the most appropriate recommendations on the best steps to take, based on the PD data.

There are other benefits that you can derive from the PD testing in your plant. For example, you will be able to avoid the unnecessary rewinds on your older electrical machines. It will also be possible for you to lower any risks of in-service failures, as well as detect machine problems early to place requests for early replacements without incurring any costs.

Through PD testing, it is possible for you to optimize your resources by focusing maintenance on those machines that have higher PD levels. Thus, you will be avoiding unnecessary and costly maintenance work on your machines.

You will also be increasing the safety levels in your plant, determining corrective action with greater precision, ensuring your corrective maintenance procedure is accurate and effective, and improving the overall reliability of your systems.

Is PD testing costly?

Relative to the cost of equipment and potential losses from outages due to disasters, PD testing is usually a very small investment. Learn more about this procedure at