The American Wire Gauge and its Effects on Direct Attach Cable Connections

When designing and maintaining an Optical Fiber Network it’s crucial to know the various features and properties of the optical network equipment. When selecting the appropriate equipment for a particular project it’s important to consider all possible options. For example selecting the correct cables for the optical networks is not the same process for copper cables and optical cables. This is due to their different manufacturing processes, their functioning and characteristics.

The American Wire Gauge or AWG represents an extremely important parameter when choosing the correct Direct Attach Cables. The American Wire Gauge is a standard method of denoting round and solid, electrically conducting capacity of a cable. Its use started in 1857 and it was used primarily in the United States and later as the years went by the rest of the world started using it. To make things clearer, the higher the AWG number, the smaller the cable is in diameter and the thinner the wire inside of it. This is very important to know, keeping in mind that thicker wires have a higher capability of transmitting larger amount of current over greater distances accompanied with minimal loss. Generally the smallest AWG size is 40 AWG and the largest is 0000 or (4/0) AWG. The various AWG sizes and each of its properties is shown in the around the world accepted AWG size and properties table:

*AWG gauge*	Conductor Diameter *Inches*	Conductor Diameter mm	*Ohms per 304.8* *meter (1000ft.)*	*Ohms per km*	Maximum amps for chassis wiring	Maximum amps for power transmission	*Maximum frequency*	Breaking force Soft Annealed *Cu 37000 PSI*
*0000*	0.46	11.684	0.049	0.16072	380	302	125 Hz	2776 kg
*000*	0.4096	10.40384	0.0618	0.202704	328	239	160 Hz	2205 kg
00	0.3648	9.26592	0.0779	0.255512	283	190	200 Hz	1751 kg
0	0.3249	8.25246	0.0983	0.322424	245	150	250 Hz	1388 kg
1	0.2893	7.34822	0.1239	0.406392	211	119	325 Hz	1102 kg
2	0.2576	6.54304	0.1563	0.512664	181	94	410 Hz	875 kg
3	0.2294	5.82676	0.197	0.64616	158	75	500 Hz	694 kg
4	0.2043	5.18922	0.2485	0.81508	135	60	650 Hz	549 kg
5	0.1819	4.62026	0.3133	1.027624	118	47	810 Hz	435 kg
6	0.162	4.1148	0.3951	1.295928	101	37	1100 Hz	345 kg
7	0.1443	3.66522	0.4982	1.634096	89	30	1300 Hz	274 kg
8	0.1285	3.2639	0.6282	2.060496	73	24	1650 Hz	217 kg
9	0.1144	2.90576	0.7921	2.598088	64	19	2050 Hz	172 kg
10	0.1019	2.58826	0.9989	3.276392	55	15	2600 Hz	142 kg
11	0.0907	2.30378	1.26	4.1328	47	12	3200 Hz	113 kg
12	0.0808	2.05232	1.588	5.20864	41	9.3	4150 Hz	89 kg
13	0.072	1.8288	2.003	6.56984	35	7.4	5300 Hz	68 kg
14	0.0641	1.62814	2.525	8.282	32	5.9	6700 Hz	54 kg
15	0.0571	1.45034	3.184	10.44352	28	4.7	8250 Hz	42 kg
16	0.0508	1.29032	4.016	13.17248	22	3.7	11 k Hz	34 kg
17	0.0453	1.15062	5.064	16.60992	19	2.9	13 k Hz	27 kg
18	0.0403	1.02362	6.385	20.9428	16	2.3	17 kHz	21 kg
19	0.0359	0.91186	8.051	26.40728	14	1.8	21 kHz	16 kg
20	0.032	0.8128	10.15	33.292	11	1.5	27 kHz	13 kg
21	0.0285	0.7239	12.8	41.984	9	1.2	33 kHz	10.5 kg
22	0.0253	0.64516	16.14	52.9392	7	0.92	42 kHz	8 kg
23	0.0226	0.57404	20.36	66.7808	4.7	0.729	53 kHz	6.5 kg
24	0.0201	0.51054	25.67	84.1976	3.5	0.577	68 kHz	5 kg
25	0.0179	0.45466	32.37	106.1736	2.7	0.457	85 kHz	4 kg
26	0.0159	0.40386	40.81	133.8568	2.2	0.361	107 kHz	3.2 kg
27	0.0142	0.36068	51.47	168.8216	1.7	0.288	130 kHz	2.5 kg
28	0.0126	0.32004	64.9	212.872	1.4	0.226	170 kHz	2 kg
29	0.0113	0.28702	81.83	268.4024	1.2	0.182	210 kHz	1.5 kg
30	0.01	0.254	103.2	338.496	0.86	0.142	270 kHz	1.2 kg
31	0.0089	0.22606	130.1	426.728	0.7	0.113	340 kHz	1 kg
32	0.008	0.2032	164.1	538.248	0.53	0.091	430 kHz	800 gr
*Metric 2.0*	0.00787	0.200	169.39	555.61	0.51	0.088	440 kHz
33	0.0071	0.18034	206.9	678.632	0.43	0.072	540 kHz	589 gr
*Metric 1.8*	0.00709	0.180	207.5	680.55	0.43	0.072	540 kHz
34	0.0063	0.16002	260.9	855.752	0.33	0.056	690 kHz	498 gr
*Metric 1.6*	0.0063	0.16002	260.9	855.752	0.33	0.056	690 kHz
35	0.0056	0.14224	329	1079.12	0.27	0.044	870 kHz	417 gr
*Metric 1.4*	.00551	.140	339	1114	0.26	0.043	900 kHz
36	0.005	0.127	414.8	1360	0.21	0.035	1100 kHz	326 gr
*Metric 1.25*	.00492	0.125	428.2	1404	0.20	0.034	1150 kHz
37	0.0045	0.1143	523.1	1715	0.17	0.0289	1350 kHz	258 gr
*Metric 1.12*	.00441	0.112	533.8	1750	0.163	0.0277	1400 kHz
38	0.004	0.1016	659.6	2163	0.13	0.0228	1750 kHz	204 gr
*Metric 1*	.00394	0.1000	670.2	2198	0.126	0.0225	1750 kHz
39	0.0035	0.0889	831.8	2728	0.11	0.0175	2250 kHz	163 gr
40	0.0031	0.07874	1049	3440	0.09	0.0137	2900 kHz	131 gr

Even though there are so many different AWG sizes within the AWG standard, not all of them are used in practical applications. From a computer networking perspective the mostly used AWG sizes are:

18 and 20 AWG - coaxial cables used mainly for CATV
24 AWG - Category 5, 5e and 6 cables used mainly for Local Area Networks and Ethernet
24, 26, 28 and 30 AWG - Direct Attach Cables used mainly in Datacenter environment and interconnections

Direct Attach Cables used mainly in Datacenters are a form of high speed cables with transceivers incorporated on each end of the cable. These cables are widely popular around the world mainly because of the price difference compared with regular transceivers. There are two types of Direct Attach Cables existing: active and passive. Even though some may argue, there is no particular weight and appearance between the two types. The key difference between active and passive DACs is the integration of a driving chip in the active Direct Attach Cables. Other difference is their AWG rating. For example active Direct Attach Cables generally have lower AWG rating than passive Direct Attach Cables meaning that, for example, DAC 30 is thinner than DAC 24 and therefore more convenient for deployment at greater distances. Lower AWG rating also guarantees bigger electromagnetic shielding. When choosing DACs the longer the distance the lower the AWG value should be.

Direct Attach Cables are cheaper than the regular optics because of their transceiver connectors attached at each end. These transceivers are used only for transmitting the optical light and they don’t have the regular optical components inside of them. Thus they provide a budget solution for short range connections.

Details: Published: 07 December 2016