I am trying to research the requirement to wait or not a predetermined amount of time (“x” minutes) to re-energize an underground transmission line that was taken out of service (tripped) by a relay action.
The case I am after is the one where the cause of the outage or trip has been determined and confirmed to be external to the underground cable; in other words the UG cable is in good operating condition. We are assuming that the fault was momentary or the faulted piece has been removed, bypassed and/or repaired.
I understand that there is trapped energy in the cable even after it is de-energized; would this trapped energy have any detrimental effect on the good cable if the cable is re-energized without dissipating it?
P.S. The UG cables in our system operate at voltages ranging from 60kV up to 230kV. The type of UG cables we operate are High-Pressure Fluid-Filled (HPFF) pipe-type, High-Pressure Gas-Filled (HPGF) pipe-type and XLPE.
The case I am after is the one where the cause of the outage or trip has been determined and confirmed to be external to the underground cable; in other words the UG cable is in good operating condition. We are assuming that the fault was momentary or the faulted piece has been removed, bypassed and/or repaired.
I understand that there is trapped energy in the cable even after it is de-energized; would this trapped energy have any detrimental effect on the good cable if the cable is re-energized without dissipating it?
P.S. The UG cables in our system operate at voltages ranging from 60kV up to 230kV. The type of UG cables we operate are High-Pressure Fluid-Filled (HPFF) pipe-type, High-Pressure Gas-Filled (HPGF) pipe-type and XLPE.