Training Coordinator, Industrial Paint Manufacturer
“The safety induction for new hires was handled smoothly. Elion brought their own AV equipment and kept the session engaging. We’re thinking of repeating this monthly.”
Partial Discharge Testing Services
What is Partial Discharge Testing?
Partial Discharge (PD) Testing is a non-destructive method to detect localized dielectric breakdowns in insulation systems of high-voltage equipment. PD indicates defects or degradation within the insulation, which, if undetected, can lead to failures, costly downtime, and safety hazards.
Elion offers Partial Discharge Testing services across India for transformers, switchgear, and cables, ensuring early fault detection, equipment reliability, and insulation health monitoring.
Why is Partial Discharge Testing Important?
- Detects insulation defects early before catastrophic failure.
- Extends equipment life by allowing timely corrective actions.
- Prevents unplanned outages and production losses.
- Enhances safety by reducing the risk of arc flash and equipment explosion.
- Supports condition-based maintenance over reactive maintenance.
- Complies with IS/IEC standards and best practices for asset management.
What Equipment Requires PD Testing?
- Power Transformers (66 kV, 132 kV, 220 kV, 400 kV and above)
- Gas-Insulated Switchgear (GIS)
- Air-Insulated Switchgear (AIS)
- High Voltage Cables
- Rotating Machines (Motors & Generators)
- Bus Ducts and Terminations
Elion’s Partial Discharge Testing Services
- Offline PD Testing: Performed during planned shutdowns using coupling capacitors and PD detectors.
- Online PD Testing: Without interrupting operations, identifying active discharges under real load conditions.
- PD Mapping & Localization: Identifying exact locations of discharges using advanced detection methods.
- Frequency & Time Domain Analysis: Advanced waveform analysis for accurate diagnosis.
- PD Pattern Analysis: Identifying the nature of defects (corona, surface, internal discharge).
- Data Logging & Trending: Long-term monitoring for condition-based maintenance planning.
- Reporting: Detailed reports with PD levels, location, severity assessment, and actionable recommendations.
- Post-Test Advisory: Guidance on insulation repair, monitoring, and retesting schedules.
Standards We Follow
- IEC 60270 (High-voltage test techniques – Partial discharge measurements)
- IS 6209 (Partial discharge measurement)
- IEC 60076-3 (Transformers)
- IEEE 400 Series (Cable PD testing)
- OEM guidelines for transformers and GIS
Benefits of Choosing Elion for PD Testing
- 20+ years of high-voltage testing and condition monitoring expertise.
- Advanced PD detection instruments with high sensitivity.
- Pan-India testing capability for substations, industries, and utilities.
- Expert engineers trained in PD interpretation and analysis.
- Non-invasive testing without system damage.
- Quick turnaround with on-site reporting options.
- Actionable recommendations for asset life extension.
Our Partial Discharge Testing Process
- Pre-test Consultation: Identify critical assets and testing objectives.
- On-site Testing: Using advanced PD measuring instruments under offline or online conditions.
- Analysis: PD pattern recognition, localization, and severity assessment.
- Reporting: Detailed technical report with graphs and actionable insights.
- Recommendations: Maintenance or insulation repairs as needed.
- Post-Test Support: Planning for monitoring and retesting for continuous asset health management.
Definition – Partial Discharge Testing
Partial Discharge (PD) Testing is a diagnostic technique used to detect early electrical breakdowns or weak points in insulation systems of high-voltage electrical equipment such as transformers, switchgear, cables, generators, and motors.
Partial discharges are tiny electrical sparks that occur within insulation defects before a complete failure happens. These tiny sparks may not immediately disrupt operation but over time can grow, weakening insulation and eventually leading to costly outages or catastrophic equipment failure.
PD Testing identifies and measures these microscopic discharges so you can address issues early — improving safety, reliability, and asset life.
Contact Elion for Partial Discharge Testing
Enhance your asset reliability and prevent unplanned outages with Elion’s expert Partial Discharge Testing services.
Request a Quote or contact us at [email protected].
Client Testimonial
EHS Officer, Specialty Chemicals Unit
“Good response from our team for the chemical spill drill and awareness session. We had a minor leak last year and this training was timely. They even explained the MSDS sheet details clearly.”
HR Coordinator, Shared Services Office
“Elion conducted ergonomics training for our office support staff. They gave tips that don’t need any budget—just posture, breaks, and seating angles. Everyone found it useful.”
Logistics Supervisor, FMCG Warehouse
“Warehouse safety training was organized at our distribution center. The module covered stacking, material flow, and emergency handling. One or two team leads found the content basic, but the newcomers appreciated it.”
Site Incharge, Metro Rail Project
“The hot work and gas cutting safety training helped us address some recent near-misses. Our fabrication contractors said it was the first time anyone explained why permits matter, not just how to fill them.”
HR Manager, Corporate Insurance Firm
“We held a training on ergonomics and workstation safety. Elion’s speaker had a practical approach—suggested small furniture changes and posture tips that didn’t cost much but helped our office staff.”
Plant Head, Frozen Foods Facility
“Elion covered cold storage safety and ammonia handling well. Some of our technicians said it was the first time they understood how to respond to leaks. We may request them for a follow-up drill.”
HR Officer, Apparel Manufacturing Unit
“Our garment unit required machine safety awareness for new joiners. Elion kept it interactive and used visuals from our own plant, which the workers related to.”
Operations Manager, Steel Trading Yard
“The crane and material handling training helped reduce near misses in our yard. The trainer also gave tips that were not in the slides, based on their field experience. That made a difference.”
Admin Manager, IT Park
“We requested a training module on emergency evacuation procedures. Elion included site-specific examples which helped. The mock drill later was well-coordinated too. Our fire wardens felt more confident after the session.”
Frequently Asked Question (FAQs)
A systematic evaluation of your facility’s hygiene and sanitation practices against regulatory standards and best practices.
To detect insulation defects early and prevent failures.
Transformers, GIS, AIS, HV cables, motors.
Testing during operation to monitor live discharges.
Defects in insulation, voids, sharp edges, contamination.
No, it is a non-destructive test.
Using coupling capacitors, sensors, and analyzers.
IEC 60270, IS 6209, IEEE 400.
Depend on equipment type and manufacturer guidelines.
PD Testing is commonly performed on:
Power Transformers
Cables & Terminations
Switchgear (Indoor & Outdoor)
Generator Stator Windings
Motors & Rotating Machines
Bushings, CTs, PTs, GIS, and HV connections
Before commissioning new electrical equipment
During routine preventive maintenance cycles
After lightning strikes or overvoltage events
When unusual noise, heat, or insulation deterioration is observed
Before insurance inspections or electrical audits
After long idle periods or extended service life
Partial discharge is a small electrical discharge that occurs within insulation voids or defects under high electric stress. Unlike a full breakdown, it doesn’t immediately short the system but gradually damages insulation over time.
Even small PD activity slowly erodes insulation material. Left unchecked, this erosion can lead to complete insulation failure — resulting in outages, fires, property damage, or equipment replacement costs.
We use advanced instruments such as PD detectors, acoustic sensors, and high-frequency measurement tools that capture electromagnetic and acoustic signals produced by partial discharges.
Yes. PD testing is non-destructive and performed under controlled conditions without harming your electrical equipment.
Testing can sometimes be done online while equipment is energized (for certain assets like transformers under load), but offline testing may require planned shutdown for detailed evaluation.