ACSS/TW/HS285®

Aluminum Conductor, Ultra-High-Strength Steel Supported, Trapezoidal Wire

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Construction:

Core: Stranded ultra-high-strength HS285® steel core with zinc-5% aluminum-mischmetal alloy coating for corrosion protection
Stranding: Annealed aluminum (1350-O) trapezoidal-shaped wires with 63% conductivity

Applications and Features:

ACSS/TW/HS285® (Aluminum Conductor, Ultra-High-Strength Steel Supported, Trapezoidal Wire) combines a compact trapezoidal-wire aluminum construction with Southwire’s ultra-high-strength HS285 steel core. The annealed aluminum provides electrical conductivity, while the HS285 core carries the mechanical load and provides maximum strength for demanding transmission applications.

The trapezoidal-wire design allows additional aluminum area within a specified conductor diameter or a reduced diameter for a specified aluminum area. Area-equivalent and diameter-equivalent designs provide flexibility when balancing ampacity, resistance, weight, diameter, wind loading, ice loading, and existing structure requirements.

ACSS/TW/HS285 is particularly well suited for high-capacity reconductoring, long spans, river crossings, heavily loaded lines, and projects where improved electrical performance and maximum mechanical strength are required within existing clearance or tension limits.

Southwire batch anneals the completed conductor after stranding, allowing the aluminum to be fully annealed while supporting tighter stranding and verification of finished conductor properties after heat exposure.

HS285 steel-core tensile properties are verified after heat exposure to account for the effects of ACSS manufacturing and high-temperature operation.

Continuous operating temperature - 250°C

Specifications:

ASTM B500 Standard Specification for Metallic Coated or Aluminum-Clad Stranded Steel Core for Use in Overhead Electrical Conductors

ASTM B609 Standard Specification for Aluminum 1350 Round Wire, Annealed and Intermediate Tempers, for Electrical Purposes

ASTM B857 Standard Specification for Shaped Wire Compact Concentric-Lay-Stranded Aluminum Conductors, Coated-Steel Supported (ACSS/TW)

ASTM B958 Standard Specification for Extra-High-Strength and Ultra-High-Strength Class A Zinc–5% Aluminum-Mischmetal Alloy-Coated Steel Core Wire for Use in Overhead Electrical Conductors

Area Equal to Standard ACSR Conductor - Weights, Measurements, Electrical and Engineering Data

Stock Number	Code Word	Conductor Size	Type No.	Stranding	Cross-Sectional Area		Layers of Al	Diameter			Weight		Rated Breaking Strength	DC Resistance @ 20°C
					Cross-Sectional Area			Steel Strand	Steel Core	Complete Conductor	Weight		Rated Breaking Strength
					Al	Total		Steel Strand	Steel Core	Complete Conductor	Al	Total	Std
		kcmil		Al/St	in²	in²		in	in	in	lb/1000ft	lb/1000ft	lb	Ω/mile
TBA	Partridge/ACSS/TW	266.8	16	14/7	0.2095	0.2436	2	0.0788	0.2364	0.595	250.6	366.0	8,880	0.3263
TBA	Linnet/ACSS/TW	336.4	16	16/7	0.2642	0.3072	2	0.0884	0.2652	0.659	316.1	461.7	11,200	0.2588
TBA	Oriole/ACSS/TW	336.4	23	16/7	0.2642	0.3259	2	0.1059	0.3177	0.692	317.6	526.5	14,800	0.2577
TBA	Ibis/ACSS/TW	397.5	16	20/7	0.3122	0.3630	2	0.0961	0.2883	0.725	373.5	545.5	13,000	0.2190
TBA	Lark/ACSS/TW	397.5	23	16/7	0.3122	0.3850	2	0.1151	0.3453	0.740	375.3	621.8	17,500	0.2181
TBA	Flicker/ACSS/TW	477.0	13	18/7	0.3746	0.4232	2	0.0940	0.2820	0.776	447.7	612.2	13,000	0.1831
TBA	Hawk/ACSS/TW	477.0	16	18/7	0.3746	0.4356	2	0.1053	0.3159	0.790	448.1	654.6	15,600	0.1825
TBA	Hen/ACSS/TW	477.0	23	20/7	0.3746	0.4620	2	0.1261	0.3783	0.820	450.3	746.2	21,000	0.1817
TBA	Parakeet/ACSS/TW	556.5	13	18/7	0.4371	0.4937	2	0.1015	0.3045	0.840	522.4	714.0	15,200	0.1569
TBA	Dove/ACSS/TW	556.5	16	20/7	0.4371	0.5083	2	0.1138	0.3414	0.850	522.9	763.9	18,200	0.1564
TBA	Eagle/ACSS/TW	556.5	23	20/7	0.4371	0.5391	2	0.1362	0.4086	0.870	525.5	870.8	24,500	0.1558
TBA	Squab/ACSS/TW	605.0	16	20/7	0.4752	0.5525	2	0.1186	0.3558	0.885	568.5	830.2	19,700	0.1439
TBA	Teal/ACSS/TW	605.0	23	20/19	0.4752	0.5835	2	0.0852	0.4260	0.916	571.3	938.7	26,600	0.1434
TBA	Rook/ACSS/TW	636.0	13	20/7	0.4995	0.5642	2	0.1085	0.3255	0.893	597.0	816.0	17,300	0.1373
TBA	Grosbeak/ACSS/TW	636.0	16	20/7	0.4995	0.5808	2	0.1216	0.3648	0.909	597.6	872.8	20,700	0.1369
TBA	Scoter/ACSS/TW	636.0	23	22/7	0.4995	0.6160	2	0.1456	0.4368	0.942	600.5	994.9	27,400	0.1363
TBA	Egret/ACSS/TW	636.0	23	22/19	0.4995	0.6135	2	0.0874	0.4370	0.942	600.5	987.2	28,000	0.1364
TBA	Starling/ACSS/TW	715.5	16	20/7	0.5620	0.6535	2	0.1290	0.3870	0.958	672.3	982.1	23,300	0.1216
TBA	Redwing/ACSS/TW	715.5	23	20/19	0.5620	0.6900	2	0.0926	0.4630	0.994	675.6	1110	30,800	0.1212
TBA	Tern/ACSS/TW	795.0	7	20/7	0.6244	0.6676	2	0.0886	0.2658	0.960	745.2	891.5	14,200	0.1105
TBA	Puffin/ACSS/TW	795.0	10	18/7	0.6244	0.6857	2	0.1056	0.3168	0.980	745.9	953.4	17,700	0.1102
TBA	Condor/ACSS/TW	795.0	13	20/7	0.6244	0.7053	2	0.1213	0.3639	0.993	746.3	1020	21,700	0.1098
TBA	Drake/ACSS/TW	795.0	16	20/7	0.6244	0.7261	2	0.1360	0.4080	1.010	747.0	1091	25,900	0.1095
TBA	Mallard/ACSS/TW	795.0	23	22/19	0.6244	0.7668	2	0.0977	0.4885	1.050	750.6	1234	34,300	0.1091
TBA	Canary/ACSS/TW	900.0	13	20/7	0.7069	0.7985	2	0.1291	0.3873	1.055	844.9	1155	24,600	0.0970
TBA	Phoenix/ACSS/TW	954.0	5	30/7	0.7493	0.7878	3	0.0837	0.2511	1.044	897.7	1028	14,200	0.0927
TBA	Rail/ACSS/TW	954.0	7	32/7	0.7493	0.8011	3	0.0971	0.2913	1.061	898.6	1074	16,700	0.0926
TBA	Cardinal/ACSS/TW	954.0	13	20/7	0.7493	0.8464	2	0.1329	0.3987	1.080	895.5	1224	26,000	0.0915
TBA	Canvasback/ACSS/TW	954.0	23	24/19	0.7493	0.9201	2	0.1070	0.5350	1.149	900.8	1480	41,100	0.0909
TBA	Snowbird/ACSS/TW	1033.5	5	30/7	0.8117	0.8535	3	0.0872	0.2616	1.089	972.5	1114	15,400	0.0856
TBA	Ortolan/ACSS/TW	1033.5	7	34/7	0.8117	0.8678	3	0.1010	0.3030	1.102	973.4	1163	18,100	0.0854
TBA	Curlew/ACSS/TW	1033.5	13	22/7	0.8117	0.9169	2	0.1383	0.4149	1.131	970.1	1326	28,200	0.0845
TBA	Avocet/ACSS/TW	1113.0	5	30/7	0.8741	0.9190	3	0.0904	0.2712	1.130	1047	1199	16,300	0.0794
TBA	Bluejay/ACSS/TW	1113.0	7	34/7	0.8741	0.9346	3	0.1049	0.3147	1.143	1048	1253	19,500	0.0793
TBA	Finch/ACSS/TW	1113.0	13	38/19	0.8741	0.9850	3	0.0862	0.4310	1.190	1051	1427	30,400	0.0789
TBA	Oxbird/ACSS/TW	1192.5	5	30/7	0.9366	0.9848	3	0.0936	0.2808	1.170	1122	1285	17,500	0.0741
TBA	Bunting/ACSS/TW	1192.5	7	34/7	0.9366	1.0013	3	0.1085	0.3255	1.181	1123	1342	20,900	0.0740
TBA	Grackle/ACSS/TW	1192.5	13	38/19	0.9366	1.0553	3	0.0892	0.4460	1.225	1126	1529	32,600	0.0737
TBA	Scissortail/ACSS/TW	1272.0	5	30/7	0.9990	1.0504	3	0.0967	0.2901	1.203	1197	1371	18,700	0.0695
TBA	Bittern/ACSS/TW	1272.0	7	38/7	0.9990	1.0681	3	0.1121	0.3363	1.224	1198	1432	22,300	0.0694
TBA	Pheasant/ACSS/TW	1272.0	13	39/19	0.9990	1.1256	3	0.0921	0.4605	1.260	1201	1631	34,100	0.0691
TBA	Dipper/ACSS/TW	1351.5	7	36/7	1.0615	1.1348	3	0.1155	0.3465	1.256	1273	1521	23,700	0.0653
TBA	Martin/ACSS/TW	1351.5	13	42/19	1.0615	1.1959	3	0.0949	0.4745	1.300	1276	1732	36,200	0.0650
TBA	Bobolink/ACSS/TW	1431.0	7	36/7	1.1239	1.2016	3	0.1189	0.3567	1.290	1348	1611	25,100	0.0617
TBA	Plover/ACSS/TW	1431.0	13	40/19	1.1239	1.2663	3	0.0977	0.4885	1.337	1351	1834	38,400	0.0614
TBA	Lapwing/ACSS/TW	1590.0	7	36/7	1.2488	1.3351	3	0.1253	0.3759	1.358	1498	1790	27,900	0.0555
TBA	Falcon/ACSS/TW	1590.0	13	42/19	1.2488	1.4071	3	0.1030	0.5150	1.410	1501	2038	42,600	0.0553
TBA	Chukar/ACSS/TW	1780.0	8	38/19	1.3980	1.5120	3	0.0874	0.4370	1.445	1674	2061	35,300	0.0495
TBA	Bluebird/ACSS/TW	2156.0	8	64/19	1.6933	1.8311	4	0.0961	0.4805	1.608	2045	2512	42,100	0.0412

Diameter Equal to Standard ACSR Conductor - Weights, Measurements, Electrical and Engineering Data

Stock Number	Code Word	Conductor Size	Type No.	Stranding	ACSR with Equal Diameter			Cross-Sectional Area		Layers of Al	Diameter			Weight		Rated Breaking Strength	DC Resistance @ 20°C
					ACSR with Equal Diameter			Cross-Sectional Area			Steel Strand	Steel Core	Complete Conductor	Weight		Rated Breaking Strength
					Code Word	Size	Stranding	Al	Total		Steel Strand	Steel Core	Complete Conductor	Al	Total	Std
		kcmil		Al/St	Code Word	kcmil	Al/St	in²	in²		in	in	in	lb/1000ft	lb/1000ft	lb	Ω/mile
TBA	Calumet/ACSS/TW	565.3	16	20/7	Hawk	477.0	26/7	0.4440	0.5162	2	0.1146	0.3438	0.860	531.2	775.6	18,400	0.1540
TBA	Mohawk/ACSS/TW	571.7	13	18/7	Flicker	477.0	24/7	0.4490	0.5073	2	0.1030	0.3090	0.850	536.6	734.0	15,600	0.1527
TBA	Oswego/ACSS/TW	664.8	16	20/7	Dove	556.5	26/7	0.5221	0.6072	2	0.1244	0.3732	0.927	624.6	912.7	21,700	0.1309
TBA	Mystic/ACSS/TW	666.6	13	20/7	Parakeet	556.5	24/7	0.5235	0.5914	2	0.1111	0.3333	0.913	625.7	855.6	18,200	0.1310
TBA	Wabash/ACSS/TW	762.8	16	20/7	Grosbeak	636.0	26/7	0.5991	0.6965	2	0.1331	0.3993	0.990	716.7	1046	24,900	0.1141
TBA	Maumee/ACSS/TW	768.2	13	20/7	Rook	636.0	24/7	0.6033	0.6818	2	0.1195	0.3585	0.977	721.0	986.8	21,000	0.1137
TBA	Fraser/ACSS/TW	946.7	10	34/7	Puffin	795.0	22/7	0.7435	0.8167	3	0.1154	0.3462	1.077	892.5	1140	21,100	0.0930
TBA	Kettle/ACSS/TW	957.2	7	32/7	Tern	795.0	45/7	0.7518	0.8038	3	0.0973	0.2919	1.060	901.6	1078	16,800	0.0922
TBA	Suwannee/ACSS/TW	959.6	16	22/7	Drake	795.0	26/7	0.7537	0.8762	2	0.1493	0.4479	1.110	901.7	1316	30,700	0.0907
TBA	Columbia/ACSS/TW	966.2	13	22/7	Condor	795.0	54/7	0.7589	0.8573	2	0.1338	0.4014	1.092	907.0	1240	26,400	0.0904
TBA	Genesee/ACSS/TW	1158.0	7	34/7	Rail	954.0	45/7	0.9095	0.9734	3	0.1078	0.3234	1.165	1091	1307	20,500	0.0762
TBA	Hudson/ACSS/TW	1158.4	13	24/7	Cardinal	954.0	54/7	0.9098	1.0281	2	0.1467	0.4401	1.196	1087	1488	31,100	0.0754
TBA	Cheyenne/ACSS/TW	1168.1	5	30/7	Phoenix	954.0	42/7	0.9174	0.9645	3	0.0926	0.2778	1.155	1099	1259	17,200	0.0757
TBA	Yukon/ACSS/TW	1233.6	13	38/19	Curlew	1033.5	54/7	0.9689	1.0925	3	0.0910	0.4550	1.245	1165	1584	33,200	0.0712
TBA	Nelson/ACSS/TW	1257.1	7	36/7	Ortolan	1033.5	45/7	0.9873	1.0556	3	0.1115	0.3345	1.213	1184	1415	22,100	0.0702
TBA	Catawba/ACSS/TW	1272.0	5	30/7	Snowbird	1033.5	42/7	0.9990	1.0504	3	0.0967	0.2901	1.203	1197	1371	18,700	0.0695
TBA	Thames/ACSS/TW	1334.6	13	38/19	Finch	1113.0	54/19	1.0482	1.1812	3	0.0944	0.4720	1.290	1260	1711	35,800	0.0658
TBA	Mackenzie/ACSS/TW	1359.7	7	38/7	Bluejay	1113.0	45/7	1.0679	1.1418	3	0.1159	0.3477	1.260	1281	1531	23,900	0.0649
TBA	Truckee/ACSS/TW	1372.5	5	30/7	Avocet	1113.0	42/7	1.0780	1.1334	3	0.1004	0.3012	1.248	1292	1480	20,200	0.0644
TBA	Merrimack/ACSS/TW	1433.6	13	39/19	Grackle	1192.5	54/19	1.1259	1.2686	3	0.0978	0.4890	1.340	1354	1838	38,400	0.0613
TBA	Miramichi/ACSS/TW	1455.3	7	36/7	Bunting	1192.5	45/7	1.1430	1.2222	3	0.1200	0.3600	1.302	1371	1639	25,600	0.0607
TBA	St. Croix/ACSS/TW	1467.8	5	33/7	Oxbird	1192.5	42/7	1.1528	1.2124	3	0.1041	0.3123	1.292	1381	1583	21,600	0.0602
TBA	Rio Grande/ACSS/TW	1533.3	13	38/19	Pheasant	1272.0	54/19	1.2043	1.3571	3	0.1012	0.5060	1.380	1448	1966	41,200	0.0573
TBA	Potomac/ACSS/TW	1557.4	7	36/7	Bittern	1272.0	45/7	1.2232	1.3079	3	0.1241	0.3723	1.350	1467	1754	27,300	0.0567
TBA	Platte/ACSS/TW	1569.0	5	33/7	Scissortail	1272.0	42/7	1.2323	1.2957	3	0.1074	0.3222	1.334	1476	1691	23,100	0.0564
TBA	Pecos/ACSS/TW	1622.0	13	39/19	Martin	1351.5	54/19	1.2739	1.4428	3	0.1064	0.5320	1.420	1531	2104	45,000	0.0541
TBA	Schuylkill/ACSS/TW	1657.4	7	36/7	Dipper	1351.5	45/7	1.3017	1.3918	3	0.1280	0.3840	1.386	1561	1866	29,100	0.0533
TBA	James/ACSS/TW	1730.6	13	39/19	Plover	1431.0	54/19	1.3592	1.5316	3	0.1075	0.5375	1.470	1634	2219	46,400	0.0508
TBA	Pee Dee/ACSS/TW	1758.6	7	38/7	Bobolink	1431.0	45/7	1.3812	1.4768	3	0.1319	0.3957	1.430	1656	1980	30,900	0.0502
TBA	Cumberland/ACSS/TW	1926.9	13	42/19	Falcon	1590.0	54/19	1.5134	1.7050	3	0.1133	0.5665	1.550	1819	2469	51,600	0.0456
TBA	Athabaska/ACSS/TW	1949.6	7	44/7	Lapwing	1590.0	45/7	1.5312	1.6377	3	0.1392	0.4176	1.504	1836	2197	34,300	0.0453
TBA	Powder/ACSS/TW	2153.8	8	64/19	Chukar	1780.0	84/19	1.6916	1.8294	4	0.0961	0.4805	1.596	2043	2510	42,100	0.0412
TBA	Santee/ACSS/TW	2627.3	8	64/19	Bluebird	2156.0	84/19	2.0635	2.2318	4	0.1062	0.5310	1.761	2492	3063	51,300	0.0338

Revision: 1.000.002

Updated On: Nov. 10, 2026, 8:26 p.m. UTC