Medium Voltage Cables

Single Core XLPE Insulated Power Cable
26 / 35 kV

APPLICATION	This cable is used for urban networks. It can be installed aerially, in conduit, on open trays and in underground ducts.
VOLTAGE RATING	26/35 kV
CONSTRUCTION	Conductor: Compact round stranded copper or aluminium Conductor Shield: Semi-conducting tape and /or semi-conducting cross-linked polyethylene Insulation: Cross-linked polyethylene Insulation Shield: Semi-conducting cross-linked polyethylene Shield: Copper tape shield Filler: Polypropylene (Nonhygroscopic material) Binding Tape: Polyester and/or non-woven tape (Optional: water blocking tape) Bedding: Black polyethylene (Optional: polyvinyl chloride) Armour: Aluminium wire armoured Sheath: Black polyvinylene (ST7) (Optional: polyvinyl chloride)
SPECIFICATION	IEC60502-2

Detailed Specification

Nominal cross sectional area	Reference conductor diameter	Nominal insulation thickness	Approx overall diameter of cable	Approx weight of cable		Approx overall diameter of cable	Approx weight of cable
				Cu	Al		Cu	Al
				Non Armoured	Non Armoured		Aluminium Wire Armoured	Aluminium Wire Armoured
mm²	mm	mm	mm	kg/km	kg/km	mm	kg/km	kg/km
50	8.4	10.5	38	1635	1356	50	5157	4887
70	10.0	10.5	40	1948	1516	51	5609	5117
95	11.7	10.5	41	2294	1676	53	6115	5495
120	13.1	10.5	43	2665	1849	55	6614	5808
150	14.6	10.5	44	2975	1999	56	7097	6121
185	16.2	10.5	46	3362	2191	58	7597	6426
240	18.4	10.5	49	4006	2479	61	8472	6945
300	20.6	10.5	51	4852	2868	63	9532	7549
400	23.8	10.5	55	5700	3218	67	10680	8198
500	26.6	10.5	60	6857	3771	72	12289	9201
630	30.0	10.5	62	8214	4323	74	13258	9366
800	34.0	10.5	66	9710	5030	79	15658	11008
1000	38.2	10.5	71	12059	5866	84	18523	12331

Note :
The approx weight of cable is the weight of PVC sheathed cable

Continuous Current Capacity

Type	XLPE Insulated Unarmoured
Arrange type	Delta (connect each other)				Flat (the space between adjacent cores is the overall diameter of the cable)
Laying method Nominal cross- section area (mm²)	in air		direct buried		in air		direct buried
Laying method Nominal cross- section area (mm²)	Cu	Al	Cu	Al	Cu	Al	Cu	Al
50	215	170	260	200	250	190	225	175
70	270	210	320	250	305	240	275	215
95	330	255	390	300	375	290	335	260
120	380	295	445	345	435	335	380	295
150	430	330	500	395	490	380	425	330
185	490	380	570	440	565	435	485	375
240	575	450	665	515	665	520	565	438
300	660	515	750	585	760	590	635	495
400	765	600	865	680	890	695	730	570
500	875	695	980	775	1030	810	830	655
630	1010	810	1110	895	1200	950	950	755
800	1150	940	1250	1020	1380	1110	1080	865
1000	1260	1050	1360	1130	1540	1250	1190	960
Ambient Temperature ˚C	40°C		25°C		40°C		25°C
Operating Temperature ˚C	90°C

Technical Properties

Main Technical Properties

No	Uo/U (kV) Rated Voltage Technical properties	3.6/6 (7.2)	6/6 6/10 (12)	8.7/10 8.7/15 (17.5)	12/20 (24)	18/30	21/35	26/35
1	Conductor DC resistance (Ω/km) See next	See next table
2	Routine partial discharge test Exert 2Uo, not higher than (pC)	5
3	Routine AC. Voltage test Uo ≤ 18kV, test 3.5Uo lasting 5min Uo > 18kV, exert 3.5Uo lasting 5min or exert 2.5Uo lasting 30min	12.6/5	21/5	30.5/5	42/5	63/5	73.5/5 (or) 52.5/30	91/5 (or) 65/30
4	Power frequency AC voltage test for 4 hours (kV)	14.4	24	34.8	48	72	84	104
5	Hot Set Test 200°C 15min, 20N/cm² Max. percentage elongation at loading (%) Max. percentage elongation after cooling (%)	130 15
6	Hot impact resistance test (kV) (Heating of 5°C higher than continuous operating temperature (positive & negative pole each 10 times))	60	75	95	125	170	200	250
7	Other tests	See Q / 320481LL019 - 2003

Conductor DC Resistance

Nominal cross-sectional area (mm²) 20°C, the D.C. resistance is not more than (Ω/km)	25	35	50	70	95	120	150	185
Cu	0.727	0.524	0.387	0.268	0.193	0.153	0.124	0.0991
Al	1.20	0.868	0.641	0.443	0.320	0.253	0.206	0.164

Nominal cross-sectional area (mm²) 20°C, the D.C. resistance is not more than (Ω/km)	240	300	400	500	630	800	1000
Cu	0.0754	0.0601	0.0470	0.0366	0.0283	0.0221	0.0176
Al	0.125	0.100	0.0778	0.0605	0.0469	0.0367	0.0291

Correction coefficient of current-carrying capacity under different ambient temperature

Operating temperature of conductor (°C)	Ambient temperature (in air) (°C)
Operating temperature of conductor (°C)	10	15	20	25	30	35	40	45	50
60	1.58	1.50	1.41	1.32	1.22	1.11	1.00	0.86	0.73
65	1.48	1.41	1.34	1.26	1.18	1.09	1.00	0.89	0.77
70	1.41	1.35	1.29	1.22	1.15	1.08	1.00	0.91	0.81
80	1.32	1.27	1.22	1.17	1.11	1.06	1.00	0.93	0.86
90	1.26	1.22	1.18	1.14	1.09	1.04	1.00	0.94	0.89
105	1.22	1.19	1.15	1.11	1.08	1.04	1.00	0.95	0.91

Operating temperature of conductor (°C)	Ambient temperature (in soil) (°C)
Operating temperature of conductor (°C)	10	15	20	25	30	35
60	1.20	1.13	1.07	1.00	0.93	0.85
65	1.17	1.12	1.06	1.00	0.94	0.87
70	1.15	1.11	1.05	1.00	0.94	0.88
80	1.13	1.09	1.04	1.00	0.95	0.90
90	1.11	1.07	1.04	1.00	0.96	0.92

Correction coefficient of current-carrying capacity for different specific thermal resistivity of ground

Voltage	Sectional area	Specific thermal resistivity of ground ρ t (K.m/W)
(kV)	(mm²)	0.8	1.0	1.2	1.5	2.0
3.6/6 ~ 6/6	≤35 50~150 ≥185	1.06 1.08 1.09	1.00 1.00 1.00	0.95 0.94 0.93	0.88 0.87 0.85	0.80 0.77 0.76
6/10 ~ 12/15	≤35 50~150 ≥185	1.05 1.06 1.07	1.00 1.00 1.00	0.95 0.94 0.93	0.89 0.88 0.86	0.80 0.79 0.77
12/20 ~ 26/35	≤95 ≥120	1.05 1.06	1.00 1.00	0.95 0.94	0.90 0.83	0.82 0.80

Correction coefficient of current rating capacity for multi - cables laid in parallel in air

Array	Layer no.	Layers x Pcs	Gap between cable/cable Dia. d/De		Correction factor of current rating	Note
Plane parallel array of multi-cable			Level	Vertical
	One layer	1 x 2	-	< 5	0.89	d = Gap between cables De = outer Dia. of cables One layer: 1 x 3 ΟΟΟ Two layers: 2 x 2 ΟΟ ΟΟ Three layers: 3 x 3 ΟΟΟ ΟΟΟ ΟΟΟ
		1 x 3	-	< 0.75	0.84
	Two layers	2 x 1	< 0.5	1.9~1.5	0.99
				1.4~1.0	0.97
				< 0.5	0.90
		2 x 2	< 0.5	2~1.5	0.99
				1.49~1.5	0.97
				0.9~0.5	0.90
	Three layers	3 x 1	-	4~3	0.99
				2.9~2.0	0.97
				1.9~1.0	0.94
				< 0.5	0.85
		3 x 2	< 0.5	4~3	0.99
				2.9~2.0	0.97
		3 x 3	< 0.75	1.9~1.0	0.94
				< 0.5	0.85

Note :
Cables are kept one cable dia. from the wall.

Max. calculated permissible short - circuit for conductor

Nominal cross-section of conductor mm²	Maximum permissible short-circuit for conductor (1 sec.) kA
Nominal cross-section of conductor mm²	Maximum permissible short-circuit for conductor (1 sec.) kA	Aluminium conductor
10	1.51	0.988
16	2.39	1.56
25	3.69	2.42
35	5.15	3.37
50	7.31	4.79
70	10.2	6.68
95	13.8	9.03
120	17.4	11.4
150	21.7	14.2
185	26.7	17.5
240	34.6	22.6
300	43.1	28.2
400	57.4	37.6
500	71.7	47.0
630	88.8	58.0

Max. permissible short-circuit for current for metallic screen (copper tape screen)

Nominal cross-section of conductor mm²	Rated voltages of cable (kV)
	3.6/6 (7.2)	6/6 6/10 (12)	8.7/10 8.7/15 (17.5)	12/20 (24)	18/30	21/35	26/35
	Short-Circuit Current A
25	1075	1083	1094	-	-	-	-
35	1074	1082	1092	1096	-	-	-
50	1072	1080	1091	1095	1284	1286	1288
70	1070	1079	1090	1091	1281	1285	1286
95	1069	1077	1086	1272	1280	1284	1283
120	1068	1077	1286	1271	1279	1280	1282
150	1067	1076	1265	1270	1278	1279	1282
185	1064	1251	1264	1267	1275	1276	1279
240	1241	1250	1262	1266	1274	1275	1278
300	1239	1246	1261	1265	1270	1272	1277
400	1240	1245	1256	1260	1270	1272	1274
500	1243	1244	1253	1257	1266	1272	1273
630	1236	1238	1252	1253	1265	1270	1270

Capacitance of cable (reference value)

Nominal cross-section of conductor mm²	Rated voltages of cable (kV)
	3.6/6 (7.2)	6/6 6/10 (12)	8.7/10 8.7/15 (17.5)	12/20 (24)	18/30	21/35	26/35
	Capacitance for each phase μ F/Km
25	0.2423	0.1922	0.1576	0.1378	0.1163	0.1064	0.0992
35	0.2684	0.1922	0.1725	0.1502	0.1251	0.1140	0.1061
50	0.3022	0.2367	0.1917	0.1661	0.1363	0.1239	0.1150
70	0.3462	0.2693	0.2167	0.1868	0.1508	0.1365	0.1263
95	0.3875	0.2999	0.2400	0.2060	0.1643	0.1483	0.1368
120	0.4236	0.3266	0.2603	0.2228	0.1760	0.1584	0.1460
150	0.4647	0.3570	0.2834	0.2418	0.1893	0.1700	0.1563
185	0.5059	0.3873	0.3123	0.2656	0.2060	0.1815	0.1665
240	0.5430	0.4290	0.3439	0.2916	0.2207	0.1972	0.1805
300	0.5589	0.4706	0.3755	0.3175	0.2387	0.2128	0.1745
400	0.5940	0.5311	0.4213	0.3551	0.2648	0.2354	0.2146
500	0.6167	0.5839	0.4613	0.3880	0.2876	0.2551	0.2321
630	0.6848	0.6481	0.5099	0.4278	0.3151	0.2789	0.2533

Inductance for single-core cable (reference value)

Nominal cross-section of conductor mm²	Rated voltages of cable (kV)
	3.6/6 (7.2)	6/6 6/10 (12)	8.7/10 8.7/15 (17.5)	12/20 (24)	18/30	21/35	26/35
	Inductance mH/Km
25	0.5954	0.6143	0.6474	0.6621	0.7006	0.7168	0.7273
35	0.5753	0.5932	0.6248	0.6390	0.6762	0.6942	0.7021
50	0.5543	0.5711	0.6011	0.6145	0.6501	0.6675	0.6751
70	0.5357	0.5486	0.5765	0.5919	0.5252	0.6394	0.6467
95	0.5172	0.5318	0.5608	0.5726	0.6043	0.6180	0.6279
120	0.5059	0.5197	0.5473	0.5585	0.5891	0.6051	0.6118
150	0.4949	0.5079	0.5341	0.5449	0.5740	0.5895	0.5959
185	0.4885	0.5006	0.5252	0.5351	0.5640	0.5760	0.5839
240	0.4790	0.4890	0.5143	0.5216	0.5487	0.5615	0.5677
300	0.4749	0.4818	0.5032	0.5102	0.5376	0.5484	0.5540
400	0.4660	0.4702	0.4927	0.4991	0.5219	0.5343	0.5395
500	0.4600	0.4619	0.4848	0.4907	0.5128	0.5224	0.5272
630	0.4547	0.4563	0.4748	0.4827	0.5012	0.5101	0.5161

S - The distance between the two adjacent cable center, D - The overall diameter of the cable.

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Medium Voltage Cables

Single Core XLPE Insulated Power Cable 26 / 35 kV

Single Core XLPE Insulated Power Cable
26 / 35 kV