This standard specifies the construction, dimensions and tests for twisted-pair electrical cables (hereinafter referred to as cables) for outdoor use, insulated with cross-linked polyethylene (XLPE) operating voltages up to 0.6 /1 kV, with 2, 3 or 4 cores, with aluminum conductors, rated cross-section from 16 to 150 mm2.

Regulation of twisted cable structure

1. For conductive core

The conductor shall be of aluminum braided from technical round and pressed aluminum strands. Dimensions and specifications of conductors must be in accordance with table 1. Aluminum wires used to braid the conductor walls must comply with TCVN 5934 – 1995.

The successive layers of helix must be in opposite directions and the outermost helix must be in the right direction.

2. For insulating sheath

Insulation shall be made of XLPE material having an ash content of not less than 2% by mass. Insulation shall be uniform, firmly adhered to the conductor but still able to be separated from the conductor, and comply with tables 1 and 2 of this standard.

Insulating material can be XLPE with symbol X-90 or special XLPE with higher heat resistance, symbol X-FP-90.

3. How to identify cable core

Cable cores shall be identified by continuous floating ribs along the length of the core.

Phase cores shall have the following embossed ribs:

• for two-core twisted-pair cables: a floating tendon;
• for three-core twisted-pair cables: one core has floating ribs, the other core has two floating ribs;
• for four-core twisted-pair cables: one core has embossed ribs, the other core has two floating ribs and the third core has three floating ribs.

SUNWON twisted pair cable based on nominal cross-sectional area and number of conductor cores includes 29 products as follows:

• 2-core twisted-pair cable: The nominal cross-sectional area includes 2×11, 2×16, 2×25, 2×35, 2×50, 2×70;
• 3-core twisted-pair cable: The nominal cross-sectional area includes 3×11, 3×16, 3×25, 3×35, 3×50, 3×70, 3×95, 3×120, 3×150;
• 4-core twisted-pair cable: The nominal cross-sectional area includes: 4×11, 4×16, 4×25, 4×35, 4×50, 4×70, 4×95, 4×120, 4×150, 4×185, 4×240.