11/06/2026
Let us learn today *"What care should be taken to first energize UNDER GROUND CABLE (UGC)"*.
1. UGC is Capacitive element, needs utmost care, especially on checking of *"Sheath INTIGRITY Test"* (Use of proper EARTHING and SVL).
2. Just before charging, check the followings.
2. A. Ensure cable is not being tested with any *DC APPLICATION, that may cause with Space charge Accumulation* minimum before 12hrs, if so tested, the cable core and sheath should be discharged through EARTH.
2. B. But IR (Insulation Resistance) test with PI should be done atleast 2.5 or 5KV range *followed by DISCHARGE of cable.*
2. C. VLF AC TEST and TAN DELTA Test should be done to ensure the cable insulation.
2. D. *Ensure Sheath Intigrity check.*
2. E. Ensure that CABLE DIFFERENTIAL RELAY in use as protection device.
2. F. In case no cable differential relay, Make sure Distance relay being used with proper setting along with Earth FAULT relay.
2. G. *Never energize cable from Main system, Use Bus section/ extended bus with proper Protection system* to avoid cascade impact.
2. H. Follow also the statutory CHECK points like Cable continuity, phase identification, sheath leakage current and others.
2. I. After charging keep cable minimum 24 Hrs with soaking. *Then re-charging for loading may be done after Sheath Intigrity check (Physical check of SHEATH, Cable joint box, SVL condition, earth link box etc..)*.
