Detecting Corona Discharge
Corona discharge is a partial electrical discharge that occurs when the electric field around a high-voltage conductor is strong enough to ionise the surrounding air — but not strong enough to cause full breakdown. It appears as a faint glow or hiss and is invisible to the naked eye under daylight conditions.
Left undetected, corona discharge causes progressive insulation degradation, leading to flashovers, equipment failures, and prolonged transmission line outages. CSR Impex uses advanced UV (ultraviolet) corona cameras to locate and quantify discharge activity on live HV equipment.
All inspections are performed live — without interrupting power supply — by our experienced engineers who have extensive field experience across power generation, transmission, and distribution assets.
Why Corona Inspection Matters
Invisible to Naked Eye
Corona activity is invisible in daylight. UV cameras detect photon emissions from discharge activity that human eyes simply cannot see.
Live-Line Inspection
No shutdown required. Inspections are conducted on energised HV equipment — zero production loss, zero planned outage time.
Prevents Insulation Failure
Early corona detection allows timely maintenance before insulation degrades to flashover or catastrophic breakdown.
Transmission Line Safety
Identifies faulty insulators, damaged conductors and hardware issues on overhead transmission lines before they cause outages.
Cost Avoidance
Prevents expensive emergency repairs, forced outages, and grid disruptions. ROI on corona inspection is exceptionally high.
Quantified Severity Report
UV photon count data provides quantified discharge severity, enabling engineers to prioritise maintenance based on risk level.
Where We Apply Corona Inspection
🗼Transmission & Distribution
- Overhead transmission line insulators (33kV–765kV)
- EHV substation equipment and bus bars
- Transmission line hardware — clamps, connectors, fittings
- Damaged or contaminated string insulators
- Conductor surface defects and corona rings
🏭Substations & Switchyards
- Power transformers and bushing inspection
- Circuit breakers and isolators
- Current and voltage transformers (CT/VT)
- Surge arresters and capacitor banks
- Bus ducts and cable terminations at HV level
⚡Power Generation Plant Assets
- Generator stator windings and end turns
- Unit transformer and generator transformer bushings
- Isolated phase bus ducts
- HV motor windings in critical drives
🔬Research & Quality Assurance
- HV equipment quality testing after installation
- Pre-commissioning inspections for new assets
- Periodic condition monitoring of ageing infrastructure
- Post-repair verification of insulation systems
How a Corona Survey Works
Scope Definition
We define the inspection zone, equipment list and access requirements with your team
Live UV Survey
Our engineers scan energised equipment with UV corona cameras — day or night
Discharge Analysis
UV photon counts analysed and graded by severity — Critical, Major, Minor
Inspection Report
Detailed report with UV images, location maps, severity data and remediation actions
Request a Corona Inspection
Protect your high-voltage infrastructure from insulation failure and transmission outages. Our experienced team is ready.
Our Other Services
Thermography Inspection
FLIR infrared camera detection of heat anomalies in electrical and mechanical equipment.
Learn More →Power Quality & Meter Testing
Identify anomalies in electrical equipment and flaws in energy meters.
Learn More →HV Live Line Testing
Defective suspension insulator identification to prevent outages and safety hazards.
Learn More →