Technical Resources

We have gathered together a number of technical resources for use as reference on electrical projects.

Cable: SWA Cables

Download as PDF

Table 4E4A – Current Carrying Capacity in Ampere

• Current Rating Chart for Multicore Armoured
• Thermoplastic Insulated Cables with Copper
• Conductors at 90°C Operating Temperature Extract from the IEE Wiring Regulations, 17th Edition
• 30°C Ambient Air Temperature,
• 90°C Conductor Operating Temperature,
• 20°C Ambient Ground Temperature

Conductor cross-sectional area mm²	REFERENCE METHOD C - CLIPPED DIRECT		Method D - Direct or in ducts, in ground, in/around buildings.		Method E - In free air or on a perforated cable tray.
	1 two-core* cable, single	1 three-core* or 1 four-core	1 two-core* cable, single	1 three-core* or 1 four-core	1 two-core* cable, single	1 three-core* or 1 four-core
	phase A.C or D.C.	cable, three-phase A.C.	phase A.C or D.C.	cable, three-phase A.C.	phase A.C or D.C.	cable, three-phase A.C.
1.5	27	23	25	21	29	25
2.5	36	31	33	28	39	33
4	49	42	43	36	52	44
6	62	53	53	44	66	56
10	85	73	71	58	90	78
16	110	94	91	75	115	99
25	146	124	116	96	152	131
35	180	154	139	115	188	162
50	219	187	164	135	228	197
70	279	238	203	167	291	251
95	338	289	239	197	354	304
120	392	335	271	223	410	353
150	451	386	306	251	472	406
185	515	441	343	281	539	463
240	607	520	395	324	636	546
300	698	599	446	365	732	628
400	787	673			847	728

Table 4E4B – Voltage drop per ampere, per metre 70°C conductor operating temperature

Conductor crosssectional area mm²	Two-core cable, D.C.	Two-core cable, single phase A.C.			Three or four-core cable, three-phase A.C.
	mV/A/m	mV/A/m			mV/A/m
1.5	31	31			27
2.5	19	19			16
4	12	12			10
6	7.9	7.9			6.8
10	4.7	4.7			4.0
16	2.9	2.9			2.5
		r	x	z	r	x	z
25	1.850	1.850	0.160	1.900	1.600	0.140	1.650
35	1.350	1.365	0.155	1.365	1.150	0.135	1.150
50	0.980	0.990	0.155	1.000	0.860	0.135	0.870
70	0.670	0.670	0.150	0.690	0.590	0.130	0.600
95	0.490	0.500	0.150	0.520	0.473	0.130	0.450
120	0.390	0.400	0.145	0.420	0.340	0.130	0.380
150	0.310	0.320	0.145	0.350	0.280	0.125	0.300
185	0.250	0.260	0.145	0.290	0.220	0.125	0.260
240	0.195	0.200	0.140	0.240	0.175	0.125	0.210
300	0.155	0.160	0.140	0.210	0.140	0.120	0.185
400	0.120	0.130	0.140	0.190	0.115	0.120	0.165

Download as PDF