What is Partial Discharge?

Partial Discharge (PD) is a degenerative phenomenon that affects the electrical insulation of medium voltage (MV) & high voltage (HV) equipment.


PD is the best early warning indicator of electrical insulation degradation in assets operating at 3.3 kV and above.


PD testing and monitoring supports Condition Based Maintenance programmes – enabling operators to improve their asset reliability and avoid unplanned outages.


By providing a condition assessment of their in-service assets, HVPD help operators avoid in-service failures, reduce unplanned outages and improve their maintenance efficiency – saving them time and money.

Our Partial Discharge Technology


We supply a comprehensive range of equipment to detect and monitor On-line PD for the condition assessment of in‑service power cables, switchgear, motors and generators, and transformers rated at 3.3 kV and above. Suitable for MV, HV and EHV assets, our PD testing and monitoring technology provides you with an early warning of developing insulation faults, helping you to avoid costly failures and resulting unplanned network outages.

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  • On-line Partial Discharge Testing and Monitoring of 11 kV Switchgear for an Australian Mining Operator View case study
  • Utilising Holistic Condition Monitoring on MVIHV Motors to Reduce Unplanned Downtime Download
  • On-line Partial Discharge Condition Monitoring of Complete Networks for the Pulp and Paper Industry: Challenges and Solutions Explained Through Case Studies Download
  • A Novel Solution for the Reliable On-Line Partial Discharge Monitoring (OLPD) of VSD-Operated EX/ATEX HV Motors Download

Our Products & Services

Alongside our on-line Partial Discharge test and monitoring technology solutions, we provide a wide range of services to our clients, ensuring that the best test, sensor and monitoring solution is implemented, on a client-by-client basis. Our engineering team work closely with our customers to provide them with a tailored and cost-effective on-line Partial Discharge test and monitoring program across the complete MV/HV/EHV network. We are an extension of your asset management team.

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