DayCor ® Technology Distribution

DayCor® Technology is used to detect Corona Particle Discharge and Arcing on electric grid components. It offers you: Early warnings of potential future failures. Pinpointing & Visualizing the corona effect. Decision ability to determines the health of your critical systems components Prioritize your particle discharge maintenance challenges Day time work DayCor® Technology saves you by avoiding costly unscheduled outages and failures DayCor ® Technology

E field e e + e e + e e e + -V e UV Ph Corona is a luminous partial discharge due air ionization. The DayCor® camera pinpoints the exact source’s location by visualizing the UV photons, coming out of it. Corona Effect Corona Source Free Electron, coming out from the source Natural Air molecule UV Photon

Combined mode Visible only display UV only mode Bi-Spectral Imaging Pinpointing the exact corona’s location

UV-IR complimentary technologies No corona on IR picture Corona spots using UV technology Live End Corona Dead End Corona

It Causes Degradation of polymer (NCI) insulators Ceramic Insulator Defects Physical damage to component. Cracks the cement of pins and metal caps of porcelain insulators. Wood Pole Fires Audio noise (AN) Corona is a concern because:

Degradation of polymer (NCI) insulators To get to that point is to waste your time & money Detect this failure in advance, to take the right action at the right time Corona Spot The outcome

Polymer Termination - 33KV

Physical damaged to component Left string- OutcomeRight string - Outcome Corona spots

Cracks on 11kv insulator

Cement problem indication -11kv

Wood Pole Fire The leakage currents can generate enough localized heat to ignite the wood at the point of contact between wood and metal surfaces and start a pole fire Insulators near or at the end of their service life can cause to pole fire 25kv

Audio noise - few reasons

It indicates: Possible Faults Sealing defects Shorted bells Gap discharge Loose hardware Contamination Corrosion or erosion Bad ground connections Corona is a concern because:

Possible Faults “This is not normally a serious issue but the broken wire was running down the side of the insulator, therefore reducing the insulating value from 6 sheds down to just one. The cause of there intermittent fault over 12 months has now been found in just 2 hours with the use of the corona camera" 22kV

Possible reasons Flash burn on the top shed from lightning Slight fracture on pin hole defect 33kv Possible Faults

Corona on the connection between the bushing and the capacitor. Losing Energy it to lose Money !

Possible Faults Leaking Current Dead End Corona

Sealing Defects IndicationThe problem Hollow core insulator. The core should be sealed at the bottom with a cork/rubber plug. The cork/rubber plug was cracked compromising the seal. Without the seal, moist air was introduced into the hollow core. The dielectric properties of the insulator were changed affecting the electric field. The condition would eventually lead to insulator failure. Ameren

play Sealing Defects

Shorted Bells

Gap discharge

Contamination agricultural pollution Salt contamination Agricultural pollution Polluted conductor

Corrosion - Erosion

Bad ground connections-22kv insulator

Switchgear Corona

AN, RI, TVI concern? Decision Chart Photons per Minute Can it be damaged by corona? Corona- where? Critical component? Material type Critical location? Corona intensity? No Yes High> <Medium<5000 Low<1000 Monitor for additional signs Schedule repair or replacement Repair or replace ASAP No Yes Repair or replace ASAP

Condition D Equipment fails to perform as expected Functionally failed High Counting Rate Equipment broken Outage Potential Failure C Medium Counting Rate Failure Process Failure starts here Low Counting Rate B Equipment at Normal conditions No Corona A

“…Attempting to measure and trend levels of observed ultrasonic activity and trying to relate them to the potential seriousness of surface partial discharge or end of life is not valid and could potentially lead to misleading conclusions…” “Testing Distribution Switchgear for Partial Discharge in the Laboratory and the Field”, by EA Technology, IEEE2008 Ultrasonic