CableCURE®
Process & Technology

The CableCURE process is simple and easy to implement.  The simplicity of the process is the source for its cost-effectiveness.  The predominant cause of failures in polymeric power cables is water treeing.  The diagram below will help illustrate what a water tree is.

Water-Treeing

A.  The violet-stained region in the microscopic view of the cable sample is a water tree, which spans the entire thickness of the insulation.  The water tree is a diffuse structure of microvoids (generally unconnected, Swiss cheese like holes) in the polymer.  As the cable nears the end of its reliable life, electrical trees begin to grow from this water tree.  Once an electrical tree starts growing, the cable will fail.

B.  The inset shows an expanded view of an electrical tree.

C.  Unlike the diffuse structure of the water tree, an electrical tree has discrete channels, so it's easy to tell the difference between them.

  Step 1:  Diagnosis
Prior to injection, a series of diagnostic tests is applied to assess the condition and ability of the cable to support the required flow and pressure. The condition of the neutral is also evaluated.

Step 2:  Injection
After assessing the cables suitability for injection, CableCURE fluid is injected into the cable through a termination.  An example illustration of an injection elbow is on the left.

Step 3:  Flow-Through
Depending on conductor size and length, CableCURE fluid will take 30 minutes to 30 hours to flow through the cable.  The cable remains energized, so your customers will experience little, if any, disruption of service.

 		 For 600-amp applications, a special flow-through sealing kit converts industry-standard splices into flow-through splices.  The sealing kit, comprised of a flow-through connector, includes a proprietary sealing strategy that allows fluid to flow through the splice without encountering the splice body with fluid or fluid pressure.

Step 4:  Vacuum
A vacuum is applied to a live-front injection adaptor at the far end of the cable.  This hastens the progress of the fluid through the cable and assures a complete fill.  When the fluid arrives at the end of the cable, the vacuum tank is removed.

Step 5:  Polymerization
The CableCURE fluid rapidly diffuses from the strands into the insulation, where it polymerizes with the water in the microvoids and fills them with this highly dielectric fluid.  Since the molecules of the resulting dielectric fluid are much larger than water molecules, they lock into place, retarding the growth of future water trees.
 
 For cable 4/0 in size and larger, no soak period is required.  For smaller cables, a feed tank is left in place for a few weeks or months (depending on the cable size) to allow the necessary amount of fluid to be absorbed into the insulation.  Here, the feed tank is connected to an Elastimold® injectable elbow.