Positron Teleline 751960/13CU5, Description And Installation Manual

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Teleline HVI Single 5-card Shelf Cabinet, model 751960/13CU5
3.4 HVI Equipment Layout - Concept
All equipment that is subject to the effects of the remote ground aspect of the site
is grouped and located the High Voltage Side and the Low Voltage side of the HVI
enclosure. With the equipment laid out in this manner it is easy to determine what
potential is possible on all equipment at any time.
The CO cable cannot cross or come within 15 cm (6”) of any equipment on the low
voltage side of the HVI. The station side or low voltage side equipment cannot
cross or come within 15 cm (6”) of the CO Cable, the top of the lightning arrestor,
any other equipment that is attached to the CO cable shield, cable pairs, or the
CO side of the Teleline Shelf or the CO side of any related equipment.
3.4.1 High Voltage Side
The High Voltage side of the HVI contains equipment and wiring that is at remote
ground potential. Therefore, if the installation is complete with the connection to
the feeding cable that originates beyond the substation, it is not at a safe potential
to touch, unless using rubber gloves and standing on a rubber safety mat. In other
words, if a fault event occurs, this equipment and or wiring will be at a potential
that is stable and not subject to the Ground Potential Rise effects of the substation
grid. Therefore, if the individual is standing on the grid, the effects of the fault will
make this equipment energized to an unsafe voltage level.
The equipment normally found on this side contains but may not be limited to, the
CO cable, the cable attachment to the surge or lightning arrestor, the connection
at the top of the surge or lightning arrestor, Isolation jacks if they are installed, and
the CO side of the Teleline equipment.
The Teleline equipment is designed to isolate the personnel and equipment from
the effects of the high and the low voltage condition of this site.
3.4.2 Low Voltage Side
The low voltage side of the HVI contains equipment and wiring that is essentially
at substation ground potential. Therefore it is at a safe potential to touch. It is
important to note that the circuit wires may be at an elevated potential in relation
to the earthing or ground potential of the building or concrete floor that is being