HV & LV Electrical Services

Cable install methodology

LV cables in URD are installed in conduits via a mesh stocking attached to the cable end with a swivel and braided hauling line. The drum is mounted on a cable jinker which has spooling and recovery capabilities. Tension is controlled with a live readout sent from a loadcell mounted spindle on the guide wheel of the winch drum. Cable entry and exit of the conduits are through bell mouths and slippers. Conduits are preproven and pre-lubed before cable installation.

HV cables are installed as above with extra length left out at pole and transformer ends. Large drums with heavy weights eg. 10 tonne + are installed using a spindle controlled A Frame. This is set into place and has the drum lifted onto it by a crane. The conduits are pre-proved and pre-lubricated with heavy duty bellmouths fitted to conduit ends. Positive force via a hydraulic rotorstat controls the spindle and drum speed, which in turn removes the dead weight of the drum and cable. The controlled feed can dramatically drop pulling tensions and removes drum over run and any free spooling.

Cables into open trenches are installed using the Bond Pull Method which, along with a positive feed A Frame, reduce pulling tensions to near cable weight with the addition of evenly spaced cable rollers.