Tree wire is a specialized type of covered overhead electrical conductor primarily designed for distribution of electrical energy under normal conditions of overhead (aerial) installations. Unlike bare conductors, tree wire features insulating covering layers that provide additional protection, though they are still considered covered conductors rather than fully insulated cables and therefore carry no voltage rating.
Construction and Specifications
Tree wire conductors are made from stranded, circular compressed materials including aluminum, aluminum-alloy, copper, ACSR (Aluminum Conductor Steel Reinforced), or ACSR/AW. The construction typically includes:
- A conductor screen consisting of extruded semi-conducting conductor shield in black
- An inner insulation layer of natural color thermoplastic polyethylene (PE) or cross-linked polyethylene (XLPE)
- An outer insulation layer of thermoplastic PE or XLPE in black, grey, or red with weather or UV resistant properties
These conductors are manufactured according to several standards, including ANSI/ICEA S-121-733 for Tree Wire and Messenger Supported Spacer Cable, as well as international standards like BS EN 50397-1.
Voltage Ratings and Applications
Tree wire is available in various voltage ratings including 15kV, 25kV, 35kV, and 46kV systems. The conductors must be installed on insulators and/or spacers adequate for the service voltage. They’re rated for 75°C or 90°C normal service temperature.
Benefits and Characteristics
Tree wire offers several advantages for electrical distribution systems:
- High reliability in areas with vegetation
- Super high pressure resistance
- Reduced maintenance requirements
- Protection against momentary phase-to-ground faults caused by tree branches
- Enhanced public safety compared to bare conductors
Despite having covering layers, users should note that tree wire conductors must still be treated as uninsulated for safety purposes, and proper clearances must be maintained during installation.
Technical Parameter
Tree Wire 15kV ACSR/XLPE/HDPE
| Size (AWG or kcmil) | No. of Wires | Covering Thickness (mm) | Cable Diameter (mm) | Rated Strength (kN) | Weight (kg/km) | ||
|---|---|---|---|---|---|---|---|
| No. | Conductor Shield | Inner Layer | Outer Layer | ||||
| 6 | 6/1 | 0.38 | 1.91 | 1.91 | 13.6 | 5.28 | 188 |
| 4 | 6/1 | 0.38 | 1.91 | 1.91 | 14.8 | 8.30 | 238 |
| 3 | 6/1 | 0.38 | 1.91 | 1.91 | 15.6 | 10.2 | 271 |
| 2 | 6/1 | 0.38 | 1.91 | 1.91 | 16.5 | 12.7 | 313 |
| 1 | 6/1 | 0.38 | 1.91 | 1.91 | 17.4 | 15.6 | 362 |
| 1/0 | 6/1 | 0.38 | 1.91 | 1.91 | 18.5 | 19.4 | 424 |
| 2/0 | 6/1 | 0.38 | 1.91 | 1.91 | 19.6 | 23.3 | 496 |
| 3/0 | 6/1 | 0.38 | 1.91 | 1.91 | 20.7 | 29.4 | 584 |
| 4/0 | 6/1 | 0.38 | 1.91 | 1.91 | 22.4 | 37.1 | 699 |
| 266.8 | 18/1 | 0.38 | 1.91 | 1.91 | 23.7 | 30.3 | 713 |
| 336.4 | 18/1 | 0.38 | 1.91 | 1.91 | 25.2 | 38.2 | 847 |
Tree Wire 15kV AAAC/XLPE/HDPE
| Size (AWG or kcmil) | No. of Wires | Covering Thickness (mm) | Cable Diameter (mm) | Rated Strength (kN) | Weight (kg/km) | ||
|---|---|---|---|---|---|---|---|
| No. | Conductor Shield | Inner Layer | Outer Layer | ||||
| 48.69 | 7 | 0.38 | 1.91 | 1.91 | 15.2 | 7.83 | 223 |
| 77.47 | 7 | 0.38 | 1.91 | 1.91 | 16.8 | 12.4 | 286 |
| 123.3 | 7 | 0.38 | 1.91 | 1.91 | 19.0 | 18.9 | 383 |
| 155.4 | 7 | 0.38 | 1.91 | 1.91 | 20.1 | 23.8 | 443 |
| 195.7 | 7 | 0.38 | 1.91 | 1.91 | 21.5 | 30.0 | 521 |
| 246.9 | 7 | 0.38 | 1.91 | 1.91 | 23.0 | 37.8 | 614 |
| 312.8 | 19 | 0.38 | 1.91 | 1.91 | 24.9 | 46.5 | 740 |
| 394.5 | 19 | 0.38 | 1.91 | 1.91 | 27.4 | 58.6 | 892 |
| 465.4 | 19 | 0.38 | 1.91 | 1.91 | 28.4 | 69.2 | 1008 |
| 559.5 | 19 | 0.51 | 1.91 | 1.91 | 30.4 | 83.1 | 1168 |
| 652.4 | 19 | 0.51 | 1.91 | 1.91 | 31.8 | 97.0 | 1320 |
| 740.8 | 37 | 0.51 | 1.91 | 1.91 | 33.3 | 107 | 1463 |
Tree Wire 15kV AAC/XLPE/HDPE
| Size (AWG or kcmil) | No. of Wires | Covering Thickness (mm) | Cable Diameter (mm) | Rated Strength (kN) | Weight (kg/km) | ||
|---|---|---|---|---|---|---|---|
| No. | Conductor Shield | Inner Layer | Outer Layer | ||||
| 4 | 7 | 0.38 | 1.91 | 1.91 | 14.4 | 3.52 | 204 |
| 2 | 7 | 0.38 | 1.91 | 1.91 | 15.8 | 5.39 | 259 |
| 1/0 | 7 | 0.38 | 1.91 | 1.91 | 17.7 | 7.96 | 341 |
| 2/0 | 7 | 0.38 | 1.91 | 1.91 | 18.6 | 9.99 | 394 |
| 3/0 | 7 | 0.38 | 1.91 | 1.91 | 19.7 | 12.15 | 459 |
| 4/0 | 7 | 0.38 | 1.91 | 1.91 | 21.1 | 15.30 | 541 |
| 266.8 | 19 | 0.38 | 1.91 | 1.91 | 23.0 | 19.89 | 648 |
| 336.4 | 19 | 0.38 | 1.91 | 1.91 | 24.9 | 24.57 | 775 |
| 397.5 | 19 | 0.38 | 1.91 | 1.91 | 26.1 | 28.44 | 878 |
| 477 | 19 | 0.38 | 1.91 | 1.91 | 27.9 | 33.30 | 1017 |
| 556.5 | 37 | 0.51 | 1.91 | 1.91 | 30.1 | 39.87 | 1161 |
| 636 | 37 | 0.51 | 1.91 | 1.91 | 31.5 | 45.36 | 1295 |
| 795 | 37 | 0.51 | 2.03 | 2.03 | 34.2 | 55.62 | 1557 |
Tree Wire 3-Layer 25kV ACSR/XLPE/HDPE
| Size (AWG or kcmil) | No. of Wires | Covering Thickness (mm) | Cable Diameter (mm) | Rated Strength (kN) | Weight (kg/km) | ||
|---|---|---|---|---|---|---|---|
| No. | Conductor Shield | Inner Layer | Outer Layer | ||||
| 1/0 | 6/1 | 0.38 | 3.18 | 3.18 | 23.6 | 19.4 | 586 |
| 2/0 | 6/1 | 0.38 | 3.18 | 3.18 | 24.7 | 23.3 | 666 |
| 3/0 | 6/1 | 0.38 | 3.18 | 3.18 | 25.8 | 29.4 | 763 |
| 4/0 | 6/1 | 0.38 | 3.18 | 3.18 | 27.5 | 37.1 | 891 |
| 266.8 | 18/1 | 0.38 | 3.18 | 3.18 | 28.6 | 30.3 | 913 |
| 336.4 | 18/1 | 0.38 | 3.18 | 3.18 | 30.1 | 38.2 | 1058 |
Tree Wire 3-Layer 25kV AAAC/XLPE/HDPE
| Size (AWG or kcmil) | No. of Wires | Covering Thickness (mm) | Cable Diameter (mm) | Rated Strength (kN) | Weight (kg/km) | ||
|---|---|---|---|---|---|---|---|
| No. | Conductor Shield | Inner Layer | Outer Layer | ||||
| 48.69 | 7 | 0.38 | 3.18 | 3.18 | 20.1 | 7.83 | 358 |
| 77.47 | 7 | 0.38 | 3.18 | 3.18 | 21.7 | 12.4 | 434 |
| 123.3 | 7 | 0.38 | 3.18 | 3.18 | 23.9 | 18.9 | 547 |
| 155.4 | 7 | 0.38 | 3.18 | 3.18 | 25.0 | 23.8 | 616 |
| 195.7 | 7 | 0.38 | 3.18 | 3.18 | 26.4 | 30.0 | 704 |
| 246.9 | 7 | 0.38 | 3.18 | 3.18 | 27.9 | 37.8 | 809 |
| 312.8 | 19 | 0.38 | 3.18 | 3.18 | 29.6 | 46.5 | 939 |
| 394.5 | 19 | 0.38 | 3.18 | 3.18 | 32.1 | 58.6 | 1109 |
| 465.4 | 19 | 0.38 | 3.18 | 3.18 | 33.1 | 69.2 | 1232 |
| 559.5 | 19 | 0.51 | 3.18 | 3.18 | 35.1 | 83.1 | 1407 |
| 652.4 | 19 | 0.51 | 3.18 | 3.18 | 36.5 | 97.0 | 1569 |
| 740.8 | 37 | 0.51 | 3.18 | 3.18 | 38.0 | 107 | 1723 |
| 927.2 | 37 | 0.51 | 3.18 | 3.18 | 40.9 | 135 | 2050 |
Tree Wire 3-Layer 25kV AAC/XLPE/HDPE
| Size (AWG or kcmil) | No. of Wires | Covering Thickness (mm) | Cable Diameter (mm) | Rated Strength (kN) | Weight (kg/km) | ||
|---|---|---|---|---|---|---|---|
| No. | Conductor Shield | Inner Layer | Outer Layer | ||||
| 1/0 | 7 | 0.38 | 3.18 | 3.18 | 22.8 | 7.96 | 497 |
| 2/0 | 7 | 0.38 | 3.18 | 3.18 | 23.7 | 9.99 | 556 |
| 3/0 | 7 | 0.38 | 3.18 | 3.18 | 24.8 | 12.15 | 630 |
| 4/0 | 7 | 0.38 | 3.18 | 3.18 | 26.2 | 15.30 | 723 |
| 266.8 | 19 | 0.38 | 3.18 | 3.18 | 27.7 | 19.89 | 833 |
| 336.4 | 19 | 0.38 | 3.18 | 3.18 | 29.6 | 24.57 | 973 |
| 397.5 | 19 | 0.38 | 3.18 | 3.18 | 30.8 | 28.44 | 1086 |
| 477 | 19 | 0.38 | 3.18 | 3.18 | 32.6 | 33.30 | 1237 |
| 556.5 | 37 | 0.51 | 3.18 | 3.18 | 34.8 | 39.87 | 1398 |
| 636 | 37 | 0.51 | 3.18 | 3.18 | 36.2 | 45.36 | 1542 |
| 795 | 37 | 0.51 | 3.18 | 3.18 | 38.9 | 55.62 | 1824 |
Tree Wire 3-Layer 35kV ACSR/XLPE/HDPE
| Size (AWG or kcmil) | No. of Wires | Covering Thickness (mm) | Cable Diameter (mm) | Rated Strength (kN) | Weight (kg/km) | ||
|---|---|---|---|---|---|---|---|
| No. | Conductor Shield | Inner Layer | Outer Layer | ||||
| 1/0 | 6/1 | 0.38 | 4.45 | 3.18 | 26.1 | 19.4 | 682 |
| 2/0 | 6/1 | 0.38 | 4.45 | 3.18 | 27.2 | 23.3 | 767 |
| 3/0 | 6/1 | 0.38 | 4.45 | 3.18 | 28.4 | 29.4 | 868 |
| 4/0 | 6/1 | 0.38 | 4.45 | 3.18 | 30.0 | 37.1 | 1002 |
| 266.8 | 18/1 | 0.38 | 4.45 | 3.18 | 31.1 | 30.3 | 1028 |
| 336.4 | 18/1 | 0.38 | 4.45 | 3.18 | 32.6 | 38.2 | 1179 |
Tree Wire 3-Layer 35kV AAAC/XLPE/HDPE
| Size (AWG or kcmil) | No. of Wires | Covering Thickness (mm) | Cable Diameter (mm) | Rated Strength (kN) | Weight (kg/km) | ||
|---|---|---|---|---|---|---|---|
| No. | Conductor Shield | Inner Layer | Outer Layer | ||||
| 48.69 | 7 | 0.38 | 4.45 | 3.18 | 22.6 | 7.83 | 441 |
| 77.47 | 7 | 0.38 | 4.45 | 3.18 | 24.2 | 12.4 | 523 |
| 123.3 | 7 | 0.38 | 4.45 | 3.18 | 26.4 | 18.9 | 644 |
| 155.4 | 7 | 0.38 | 4.45 | 3.18 | 27.5 | 23.8 | 718 |
| 195.7 | 7 | 0.38 | 4.45 | 3.18 | 28.9 | 30.0 | 811 |
| 246.9 | 7 | 0.38 | 4.45 | 3.18 | 30.4 | 37.8 | 922 |
| 312.8 | 19 | 0.38 | 4.45 | 3.18 | 32.1 | 46.5 | 1059 |
| 394.5 | 19 | 0.38 | 4.45 | 3.18 | 34.6 | 58.6 | 1238 |
| 465.4 | 19 | 0.38 | 4.45 | 3.18 | 35.6 | 69.2 | 1365 |
| 559.5 | 19 | 0.51 | 4.45 | 3.18 | 37.6 | 83.1 | 1547 |
| 652.4 | 19 | 0.51 | 4.45 | 3.18 | 39.0 | 97.0 | 1715 |
| 740.8 | 37 | 0.51 | 4.45 | 3.18 | 40.5 | 107 | 1874 |
| 927.2 | 37 | 0.51 | 4.45 | 3.18 | 43.4 | 135 | 2213 |
Tree Wire 3-Layer 35kV AAC/XLPE/HDPE
| Size (AWG or kcmil) | No. of Wires | Covering Thickness (mm) | Cable Diameter (mm) | Rated Strength (kN) | Weight (kg/km) | ||
|---|---|---|---|---|---|---|---|
| No. | Conductor Shield | Inner Layer | Outer Layer | ||||
| 1/0 | 7 | 0.38 | 4.45 | 3.18 | 25.3 | 7.96 | 590 |
| 2/0 | 7 | 0.38 | 4.45 | 3.18 | 26.2 | 9.99 | 653 |
| 3/0 | 7 | 0.38 | 4.45 | 3.18 | 27.3 | 12.15 | 731 |
| 4/0 | 7 | 0.38 | 4.45 | 3.18 | 28.7 | 15.30 | 829 |
| 266.8 | 19 | 0.38 | 4.45 | 3.18 | 30.2 | 19.89 | 946 |
| 336.4 | 19 | 0.38 | 4.45 | 3.18 | 32.1 | 24.57 | 1094 |
| 397.5 | 19 | 0.38 | 4.45 | 3.18 | 33.3 | 28.44 | 1210 |
| 477 | 19 | 0.38 | 4.45 | 3.18 | 35.1 | 33.30 | 1369 |
| 556.5 | 37 | 0.51 | 4.45 | 3.18 | 37.3 | 39.87 | 1538 |
| 636 | 37 | 0.51 | 4.45 | 3.18 | 38.8 | 45.36 | 1688 |
| 795 | 37 | 0.51 | 4.45 | 3.18 | 41.4 | 55.62 | 1980 |
Tree Wire 3-Layer 46kV AAAC/XLPE/HDPE
| Size (AWG or kcmil) | No. of Wires | Covering Thickness (mm) | Cable Diameter (mm) | Rated Strength (kN) | Weight (kg/km) | ||
|---|---|---|---|---|---|---|---|
| No. | Conductor Shield | Inner Layer | Outer Layer | ||||
| 48.69 | 7 | 0.38 | 5.72 | 4.45 | 27.7 | 7.83 | 640 |
| 77.47 | 7 | 0.38 | 5.72 | 4.45 | 29.3 | 12.4 | 734 |
| 123.3 | 7 | 0.38 | 5.72 | 4.45 | 31.5 | 18.9 | 873 |
| 155.4 | 7 | 0.38 | 5.72 | 4.45 | 32.6 | 23.8 | 955 |
| 195.7 | 7 | 0.38 | 5.72 | 4.45 | 34.0 | 30.0 | 1060 |
| 246.9 | 7 | 0.38 | 5.72 | 4.45 | 35.5 | 37.8 | 1182 |
| 312.8 | 19 | 0.38 | 5.72 | 4.45 | 37.2 | 46.5 | 1332 |
| 394.5 | 19 | 0.38 | 5.72 | 4.45 | 39.7 | 58.6 | 1531 |
| 465.4 | 19 | 0.38 | 5.72 | 4.45 | 40.7 | 69.2 | 1666 |
| 559.5 | 19 | 0.51 | 5.72 | 4.45 | 42.7 | 83.1 | 1864 |
| 652.4 | 19 | 0.51 | 5.72 | 4.45 | 44.1 | 97.0 | 2043 |
| 740.8 | 37 | 0.51 | 5.72 | 4.45 | 45.6 | 107 | 2214 |
| 927.2 | 37 | 0.51 | 5.72 | 4.45 | 48.5 | 135 | 2575 |
Tree Wire 3-Layer 46kV AAC/XLPE/HDPE
| Size (AWG or kcmil) | No. of Wires | Covering Thickness (mm) | Cable Diameter (mm) | Rated Strength (kN) | Weight (kg/km) | ||
|---|---|---|---|---|---|---|---|
| No. | Conductor Shield | Inner Layer | Outer Layer | ||||
| 1/0 | 7 | 0.38 | 5.72 | 4.45 | 30.4 | 7.96 | 810 |
| 2/0 | 7 | 0.38 | 5.72 | 4.45 | 31.3 | 9.99 | 880 |
| 3/0 | 7 | 0.38 | 5.72 | 4.45 | 32.4 | 12.15 | 968 |
| 4/0 | 7 | 0.38 | 5.72 | 4.45 | 33.8 | 15.30 | 1077 |
| 266.8 | 19 | 0.38 | 5.72 | 4.45 | 35.3 | 19.89 | 1205 |
| 336.4 | 19 | 0.38 | 5.72 | 4.45 | 37.2 | 24.57 | 1367 |
| 397.5 | 19 | 0.38 | 5.72 | 4.45 | 38.4 | 28.44 | 1494 |
| 477 | 19 | 0.38 | 5.72 | 4.45 | 40.2 | 33.30 | 1666 |
| 556.5 | 37 | 0.51 | 5.72 | 4.45 | 42.4 | 39.87 | 1853 |
| 636 | 37 | 0.51 | 5.72 | 4.45 | 43.9 | 45.36 | 2014 |
| 795 | 37 | 0.51 | 5.72 | 4.45 | 46.5 | 55.62 | 2326 |