Introducing Energized Medium & High Voltage Cable Testing
Formerly, reliable results required de-energizing and grounding the system, then disconnecting primary feed cables, all of which takes time:
• Traditional “Hi-Pot” testing could cause damage and extend an outage
• VLF – Very Low Frequency is the alternative method but still requires an outage
and over-voltage could cause damage and extend an outage
• Avoid the costs and risks of older technology by utilizing online PD-testing.
ONLINE NON-DESTRUCTIVE PARTIAL DISCHARGE TESTING
(shown in photos above)
• Data acquisition without shutdown at operating voltage
• Signal analyses & pattern recognition at high frequencies determine defect type
• Measures both pre-discharge and partial discharge
• Evaluate age* differences between sections of cable
* age is not chronological age but accounts for duty use
Results: Accurate CapEx planning by ranking sections from 1-5
1. A-OK, no worries …………………………………Retest every 3rd year
2. < 5% chance of failure within 2 years ……….Retest every 2nd year
3. 18% chance of failure within 2 years ……….Retest every 2nd year
4. 34% chance of failure within 2 years ……….Plan replacement soon
5. 89% chance of failure within 2 years ……….Plan replacement now
