XLPE MV Jackets Bring Sustainable Benefits

XLPE jackets can allow reduced copper content and higher operating efficiencies.

If you're a utility engineer or buyer interested in renewable energy initiatives, you should know about Southwire's line of MV jackets using crosslinked polyethylene (XLPE). XLPE jackets promise sustainability benefits including:

Potential reduction of copper content – and overall cable cost – by reducing the number of concentric neutral wires
Potential lower operating costs and energy losses over the life of the cable

"The overall cost and sustainability benefits of XLPE jackets make them a cost-reducing alternative to the commonly used linear low density polyethylene (LLDPE) jackets," says Emory Barber, director of cable and systems engineering for Southwire's Energy Division.

XLPE temperature tolerance reduces copper costs

XLPE jackets reduce overall cable costs because XLPE jackets require fewer neutral wires than LLDPE jackets. The reduction occurs because XLPE allows much higher transient short-circuit operating temperatures. According to ANSI/ICEA P-45-482-2007,

LLDPE jackets are limited to transient (10 cycles or less) short-circuit temperatures of 200°C or less.
XLPE jackets can tolerate transient short-circuit temperatures up to 350°C.

Higher allowable temperatures mean that a smaller number of neutral wires can carry the same short-circuit current. For a typical 35kv cable with conductors in the 350 – 1250 kcmil range, XLPE jackets may permit a 25 percent reduction in neutral wire copper content. Reducing the number of concentric neutral wires reduces overall cable costs.

In addition, XLPE jackets handle continuous operating temperatures up to 90°C versus 75°C for LLDPE. This can simplify application engineering.

XLPE also reduces energy losses

Compared with LLDPE, XLPE electrical characteristics reduce life-cycle operating losses. Shield losses due to circulating currents go down by approximately 2 percent, which brings energy costs down. XLPE also offers better mechanical characteristics. While typical wind installations of XLPE are direct buried, some applications require MV cable in duct. When used in a duct application, XLPE has a lower coefficient of friction for easier, faster pulling. XLPE's higher abrasion-resistance can also reduce potential cable damage during installation.

"XLPE jackets for MV Cables are an extension of Southwire's broad knowledge base in crosslinked low-voltage insulation technology," says Barber, "Southwire customers continue to benefit from Southwire's 40 years of MV experience."