Acceptance and Maintenance Testing of Medium Voltage Cable

Megger CB-360-DC/CB-120-DC DC Circuit Breaker Test SetsOver the years there have been several methods and/or philosophies regarding the testing of underground electrical power cable. The Insulated Conductor Committee of the IEEE Power Society has divided these methods or philosophies into two fundamental categories, Type 1 Field Tests and Type 2 Field Tests. 

Type 1 tests are intended to detect defects in the insulation of the cable system in order to improve the service reliability after the defective part is removed and appropriate repairs are performed.  These tests are usually achieved by application of moderately increased voltages across the insulation for a prescribed duration.  Such tests are categorized as pass/fail.  Tests include:
 
DC Hipot (IEEE 400.1 – GUIDE FOR FIELD TESTING OF LAMINATED DIELECTRIC, SHIELDED POWER CABLE SYSTEMS RATED 5 KV AND ABOVE WITH HIGH DIRECT CURRENT VOLTAGE)

VLF Hipot (IEEE 400.2 – GUIDE FOR FIELD TESTING OF SHIELDED POWER CABLE SYSTEMS USING VERY LOW FREQUENCY (VLF))
 
Type 2 tests are intended to provide indications that the insulation system has deteriorated, hence, are termed “diagnostic” tests. These tests include:
 
• Dissipation Factor (Tan Delta) Testing
• Partial Discharge (IEEE 400.3 – GUIDE FOR PARTIAL DISCHARGE TESTING OF SHIELDED POWER CABLE SYSTEMS IN A FIELD ENVIRONMENT)
• Oscillating Wave Testing
• Dielectric Discharge (not mentioned in the IEEE 400 document)
• Relaxation Current (not mentioned in the IEEE 400 document, and
• Return Voltage (not mentioned in the IEEE 400 document)

Megger CB-360-DC/CB-120-DC DC Circuit Breaker Test Sets

High Voltage PTS-75 75kV DC Hipot with Megohmmeter

High Voltage VLF-65E 65kV VLF Tester

Baker ST112A 12kV Surge Tester


Visit Our Website