Just to open this discussion to the general forum, for educational purposes only.


When a URD system is fed from an overhead primary source, the connection is made at the cable pole. The device that actually makes the connection is a “pothead” (Figure 2-1). One end of the “pothead” is connected to the overhead primary and the other end is connected to the URD primary cable. The “pothead” provides the connection between the URD system and the Overhead System and a termination point for the URD cable insulation.


Question - How is the physical connection to the primary overhead phase cable made. Is the connection a clamp connection to the overhead cable or is it a terminal connection?

This connections is a terminal connections to the bottom of a cut out or primary fuse. The top of the cut is connected by a hot line clamp. The cutout can be opened to kill the urd area for transformer work or replacement or it will blow open if there is a fault. The top is connected by a hot line clamp so this can be lifted off using sticks since killing this feed will turn off a lot of people that are off the overhead primary feed.

These are crimped together. The preparation and crimping is fussy work and has to be just right. Around here the voltage is around 13,000 volts, spark plug type voltages.