P&R Technologies’ SpanGuard ABS and EHV markers are constructed of K-10 ABS with a special UV weather cap that ensures superior color retention and prevents fading, cracking or breaking. It has 15 times the weatherability and color retention of fiberglass.
SpanGuard markers are securely attached to the live conductor, OPGW or shield wire with spiral-formed armor rods. These spiral preforms extend outward from the marker and actually reinforce and protect the conductor at the point of attachment. Completely slip-proof, they prevent line damage often associated with clamps that dig into the line. The preforms are matched at time of order to the specific size, type and diameter of line.
The EHV markers use the same K-10 ABS material as the standard markers but have a special coating and other design features to reduce corona effects that can degrade and discolor a standard marker, or even lead to burning or melting.
While non-EHV markers have been installed on lines up to 135 kV to 150 kV, corona damage can take years to develop. Atmospheric contaminants, bird nests and other factors can accelerate the process. For this reason, P&R Tech recommends that EHV markers be installed on energized lines above 115 kV.
P&R Tech also offers all-aluminum power line markers, which are constructed from aluminum for direct attachment to high-corona, high-voltage ACSS/ACCR lines and are rated up to 250°C (482°F) and 500 kV. Plastic and fiberglass markers can melt or burn in those conditions.
SpanGuard markers are easy to install on the ground or from a bucket, and they are ideally suited to installation by helicopter. This makes it possible to install markers on otherwise inaccessible lines across rivers or deep canyons, or where it is not feasible to take the line out of service.
P&R Technologies Inc.| www.pr-tech.com