What are Partial Discharges?

PD partial discharges are localised electrical phenomena occurring inside solid insulation of electrical equipment.

These discharges, although imperceptible to the naked eye, can be crucial indicators of potential problems in transformers, cables and generators.

Our Partial Discharge Measurement service allows you to identify localised weak points in the insulation system, avoid critical failures and save costs on unscheduled machine downtime.

Online Partial Discharge Measurement

Online partial discharge measurements are not only sensitive to partial discharges, but also to various electric arcs and sparks.

When performing a condition assessment of rotating machines, this technique, partial discharge measurement, provides information on:

  • Weaknesses of the insulation system
  • Degradation processes
  • Maintenance measures and service intervals
Online measurements are often more accurate than offline measurements, because the sensors are installed in a scheduled outage and the measurements are taken while the rotating machine is running and connected to the mains. Production is not required to stop!
Online partial discharge measurements are recorded with the rotating machine subjected to all TEAM operating stresses: thermal, electrical, environmental and mechanical.

Advantages of carrying out an online PD measurement

  • The voltage distribution in the winding is the same as during operation.
  • Measurements are made at operating temperature.
  • There are normal mechanical forces.

Our PD Measurement Service

1. Sensor installation: proper and safe installation without affecting the system.

2. Standardisation/Calibration: Partial discharge pulse verification and simulation process.

3. Measurement: measurement is carried out by means of specialised software.

4. Analysis, diagnosis and reporting

Servicio medición DP

Measurement Process

For the measurement process we use Omicron’s MONTESTO 200 system, a portable solution for online monitoring of partial discharges.

We perform measurements on various medium and high voltage electrical assets under load to monitor PD activity and assess the condition of the insulation.

The automated functions of the software allow us to quickly and reliably detect insulation faults and locate the sources of the signals.


UNE – EN IEC 60034-27 Rotating Electrical Machines

The standard establishes guidelines for assessing and measuring PD partial discharges (offline and online) that can occur in the insulation of stator windings of rotating electrical machines.

UNE-EN IEC 60034-27-1 Measurements of offline partial discharges in the stator winding insulation of rotating electrical machines.

UNE-EN IEC 60034-27-2 Online partial discharge measurements on the stator winding insulation of rotating electrical machines.

Do you want more information about our services?

Ask about our Calibration and Verification service.

One of our specialists will contact you as soon as possible.


    This site is protected by reCAPTCHA and the GooglePrivacy Policy and Terms of Service apply.