Our advanced partial discharge testing solutions help you detect cable faults early and ensure reliable MV, HV, and EHV systems. From factory tests to in‑service monitoring, we keep your network safe, efficient, and future‑ready.
Ensuring the safety and longevity of MV, HV, and EHV cable systems is essential for reliable operations. Megger’s PD testing solutions detect early‑stage faults and support commissioning, field evaluation, and in‑service monitoring, enabling informed decisions.
Megger’s PD testing and monitoring solutions help detect insulation issues early across MV, HV, and EHV cable systems, reducing unplanned outages and supporting stable, long‑term performance of critical network assets.
Advanced PD analytics and decades of expertise give you clear insights into cable health. From commissioning to in‑service monitoring, you gain actionable data to make confident, condition‑based decisions and extend asset life.
Partial discharge testing identifies small electrical discharges within the insulation of MV, HV, and EHV cables and accessories. These seemingly minor discharges are early indicators of insulation degradation that could lead to catastrophic failures. With Megger’s PD testing tools and monitoring solutions, businesses gain predictive insights to address these risks proactively, ensuring uninterrupted operations and compliance with safety standards.
PD testing and monitoring iscritical for industries reliant on MV/HV/EHV cable systems, such as utilities, renewables, manufacturing, transportation, heavy industry, data centres, and smart grids. Whether ensuring operational safety in industrial plants or maintaining energy flow in utility networks, tackling insulation issues early can save both time and money.
Megger offers devices for standardised FAT with the ICMcompact or ICMneo, advanced equipment, such as ICMflex for PD fault location combined with TD, HV DAC series for high-voltage diagnostics, and TDS NT for combining cable testing and diagnosis. Additionally, Megger provides custom HFCT sensors and a monitoring system such as the ICMobserver that can be tailored to various applications.
Begin by consulting with one of our experts to assess your specific needs. Whether you require on-site testing, continuous monitoring, or diagnostic solutions, Megger’s team ensures seamless integration into your processes.
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Polyethylene is a ‘non-forgiving’ insulation system. Therefore, close attention must be paid to partial discharge (PD) activity during factory testing, commissioning, and in-service monitoring. On-site measurement techniques need to cover both the needs of an ageing polymeric cable distribution network and the increasing application of polyethylene extra high voltage (EHV) cables.
Cables are generally factory tested and the accessories of high voltage (HV) and extra high voltage (EHV) cables are usually also pre-tested. However, mechanical forces during cable laying, as well as hidden imperfections and flaws caused by improper handling, require partial discharge commissioning tests.
Ideally, the cable accessories of such transmission-class cables are equipped with embedded sensors. Megger introduced this cost-effective principle in 1994 and numerous cable manufacturers have implemented it since then. The ICMsystem, especially if enhanced with the FOsystem for optical isolation, offers powerful tools for analysing the cable insulation system. Additionally, the instrumentation can be completed with different preamplifiers and embedded or external spectrum analysers.
As with HV and EHV cables, the ICMcompact is used for shop-floor production testing on medium voltage cables. ICMflex applications include HV/MV cable acceptance testing, MV/HV cable on-site testing, and testing of cable joints and accessories (both in the laboratory and on-site).
Over the past decade, numerous cable manufacturers have adopted this instrument during the modernisation of their test facilities. A large population of service-aged MV or distribution-class cables has reached their projected service life, as polymeric cables were introduced in the 1970s.
The ICMcompact is available in a ready-to-use package for field testing and partial discharge location with any external HV source. This is particularly effective in combination with very low frequency (VLF) sources and, when combined with variable frequency resonant test sets, it can provide a lightweight and cost-effective solution to help maintain the reliability of the distribution grid. Additionally, the instrument includes a T-filter and coupling unit to reduce the high frequency disturbance signals from the high-voltage source.
Generally, partial discharge (PD) monitoring can be used to detect incipient breakdown and ongoing degradation in any high-voltage insulation system. However, the defect mechanisms for cable accessories and the cable itself may differ due to variations in material properties.
When monitoring extra-high-voltage (EHV) cable systems, a relatively long prewarning time typically applies to ethylene-propylene rubber (EPR) and ethylene-propylene-diene monomer (EPDM) accessories. In contrast, the cable insulation of a 400 kV cross-linked polyethylene (XLPE) cable may have a much shorter prewarning time.
An installed monitoring system can also be used for the commissioning testing of the cable system. Besides using fiber-optic TCP/IP interconnection, accessing the instruments via wireless LAN (WLAN) can offer a more convenient installation.
Coupling capacitors, as used for factory testing and for offline testing, are not applicable for online testing. Megger offers several types of external sensors for partial discharge (PD) measurements.
The differential foil sensor (DFS) makes use of the stray capacitance of cross-bonding joints and can provide comparable low-noise measurements at higher frequencies. The CT100 is a clamp-on high-frequency (HF) current transformer that can be used to pick up partial discharge signals on ground leads and on cross-bonding connections.
Additionally, Megger can provide customized sensors, including Rogowski coils, tailored for specific applications. The company also assists with the design and implementation of embedded sensors.
