A Pragma Group Company

Partial discharge analyser (Acoustic)

AR 700 Acoustic PD Analy

AR-700 Acoustic PD Analyser

aAcoustic test on Transformer

Acoustic test on Transformer


Acoustic partial discharge monitoring is an effective on-line predictive maintenance test for identifying and locating sources of partial discharge in oil filled equipment such as transformers, gas insulated switchgear, cable joints and other HV equipment. The benefits of on-line testing allow for equipment analysis and diagnostics during normal production without having to de-energise or shut down plant. Corrective actions can be planned and implemented, resulting in reduced unscheduled downtime.

AR-700 Acoustic PD Analyser

The AR-700 has four acoustic PD inputs and one electrical PD input. Combining the use of acoustical and electrical detection allows not only for a detection and location of insulation problems but also to quantify the severity of the problem.

The use of acoustics provides three key advantages:

• The use of acoustical PD detection is helpful in high voltage substations where there may be a very high level of electromagnetic noise caused by aerial corona discharges. These discharges are for example external to the transformer. Acoustic sensors are immune to these electromagnetic noises.

• Acoustic detection can be used for walk in tests on equipment that does not have pre-installed PD sensors. A sensor can be installed on enclosures of oil filled or SF6 equipment or cable splices without taking equipment out of service by just providing good acoustical contact between the sensor and grounded enclosure.

• Acoustic PD detection can be used to not only identify but also triangulate the source or location of the PD activity in transformers, by positioning the acoustic PD sensors as close to the PD source as possible.

For more information contact Martec or visit the EDI website.