Building a Solar System? Get the Right Wire.

Solaris stocks USE-2, PV wire, battery cable, and copper building wire in the exact AWG sizes you need.

AWG	Diameter (in)	Diameter (mm)	Area (mm²)	Resistance (Ω/1000ft)	Resistance (Ω/km)	Max Current (A)	Max Freq (100% Skin)
0000 (4/0) ☼	0.46	11.684	107	0.049	0.161	302	125 Hz
000 (3/0)	0.4096	10.404	85	0.0618	0.203	239	160 Hz
00 (2/0) ☼	0.3648	9.266	67.4	0.0779	0.256	190	200 Hz
0 (1/0)	0.3249	8.252	53.5	0.0983	0.322	150	250 Hz
1	0.2893	7.348	42.4	0.1239	0.406	119	325 Hz
2 ☼	0.2576	6.543	33.6	0.1563	0.513	94	410 Hz
3	0.2294	5.827	26.7	0.197	0.646	75	500 Hz
4 ☼	0.2043	5.189	21.2	0.2485	0.815	60	650 Hz
5	0.1819	4.620	16.8	0.3133	1.028	47	810 Hz
6 ☼	0.162	4.115	13.3	0.3951	1.296	37	1100 Hz
7	0.1443	3.665	10.5	0.4982	1.634	30	1300 Hz
8 ☼	0.1285	3.264	8.37	0.6282	2.060	24	1650 Hz
9	0.1144	2.906	6.63	0.7921	2.598	19	2050 Hz
10 ☼	0.1019	2.588	5.26	0.9989	3.276	15	2600 Hz
11	0.0907	2.304	4.17	1.26	4.133	12	3200 Hz
12 ☼	0.0808	2.052	3.31	1.588	5.209	9.3	4150 Hz
13	0.072	1.829	2.62	2.003	6.570	7.4	5300 Hz
14 ☼	0.0641	1.628	2.08	2.525	8.282	5.9	6700 Hz
15	0.0571	1.450	1.65	3.184	10.444	4.7	8250 Hz
16	0.0508	1.290	1.31	4.016	13.172	3.7	11 kHz
17	0.0453	1.151	1.04	5.064	16.610	2.9	13 kHz
18	0.0403	1.024	0.823	6.385	20.943	2.3	17 kHz
19	0.0359	0.912	0.653	8.051	26.407	1.8	21 kHz
20	0.032	0.813	0.518	10.15	33.292	1.5	27 kHz
21	0.0285	0.724	0.41	12.8	41.984	1.2	33 kHz
22	0.0254	0.645	0.326	16.14	52.939	0.92	42 kHz
23	0.0226	0.574	0.258	20.36	66.781	0.729	53 kHz
24	0.0201	0.511	0.205	25.67	84.198	0.577	68 kHz
25	0.0179	0.455	0.162	32.37	106.174	0.457	85 kHz
26	0.0159	0.404	0.129	40.81	133.857	0.361	107 kHz
27	0.0142	0.361	0.102	51.47	168.822	0.288	130 kHz
28	0.0126	0.320	0.081	64.9	212.872	0.226	170 kHz
29	0.0113	0.287	0.0642	81.83	268.402	0.182	210 kHz
30	0.01	0.254	0.0509	103.2	338.496	0.142	270 kHz
31	0.0089	0.226	0.0404	130.1	426.728	0.113	340 kHz
32	0.008	0.203	0.032	164.1	538.248	0.091	430 kHz
33	0.0071	0.180	0.0254	206.9	678.632	0.072	540 kHz
34	0.0063	0.160	0.0201	260.9	855.752	0.056	690 kHz
35	0.0056	0.142	0.016	329	1079.12	0.044	870 kHz
36	0.005	0.127	0.0127	414.8	1360	0.035	1100 kHz
37	0.0045	0.114	0.01	523.1	1715	0.0289	1350 kHz
38	0.004	0.102	0.00797	659.6	2163	0.0228	1750 kHz
39	0.0035	0.089	0.00632	831.8	2728	0.0175	2250 kHz
40	0.0031	0.079	0.00501	1049	3440	0.0137	2900 kHz

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Understanding the AWG Table

AWG General Notes

American Wire Gauge (AWG) is a standardized wire gauge system used predominantly in the United States to note the diameter of electrically conducting wire. The general rule of thumb is for every 6 gauge decrease the wire diameter doubles and every 3 gauge decrease doubles the cross-sectional area. Note that W&M Wire Gauge, US Steel Wire Gauge, and Music Wire Gauge are different systems.

Diameter

A mil is a unit of length equal to 0.001 inch (a "milli-inch" or "thousandth of one inch"), i.e. 1 mil = 0.001". Wire diameters are commonly expressed in mils for smaller gauge sizes.

Resistance

The resistance values noted in the table above are for copper wire conductors. For a given current, you can use the noted resistance and apply Ohm's Law to calculate the voltage drop across the conductor. This is particularly important in solar installations where long wire runs can cause significant voltage drop if undersized wire is used.

Current (Ampacity)

The current ratings shown in the table are for power transmission and have been determined using the rule of 1 amp per 700 circular mils, which is a very conservative rating. For reference, the National Electrical Code (NEC) notes the following ampacity for copper wire at 30°C:

Always check your local electrical code for the correct current capacity (ampacity) for mains and in-wall wiring.

Skin Effect and Skin Depth

Skin effect is the tendency of an alternating electric current (AC) to distribute itself within a conductor so that the current density near the surface of the conductor is greater than that at its core. The electric current tends to flow at the "skin" of the conductor. The skin effect causes the effective resistance of the conductor to increase with the frequency of the current. The maximum frequency shown is for 100% skin depth (i.e. no skin effects).

How to Convert From Copper to Aluminum Conductors

A commonly used rule of thumb for converting conductor metals is to use aluminum two AWG sizes larger than copper for equivalency. This works in most cases within the AWG system. The technically correct method is to select an equivalent or higher ampacity rating while maintaining the same conductor temperature rating.

For example, to replace a No. 6 AWG copper TW conductor (rated 55A at 60°C per NEC Table 310-16), select a No. 4 aluminum conductor from the same 60°C column. Always make conversions by selecting equivalent or larger ampacity while maintaining the same conductor temperature rating.

Equipment rated 100 amperes or less is tested and listed for use with 60°C rated conductors unless marked otherwise. Using a higher-temperature ampacity rating to justify a size-for-size replacement effectively voids the equipment listing and violates NEC section 110-3(b).