The 9 Major Differences Between Aluminum and Copper Busbar

Bus bars play an indispensable role in the electrical industry, with two main conductor materials being aluminum and copper. So, what are the similarities and differences between aluminum and copper bus bars?

This article will delve into their conductivity, strength, resistance, current carrying capacity, cost, recyclability, and more. By comparing the characteristics of aluminum and copper bus bars, we aim to help you better understand how to choose the appropriate bus bar material for different project requirements.

Copper bus bar

Copper bus bars are known for their high conductivity and excellent machinability. As one of the oldest conductor materials, copper exhibits excellent electrical conductivity and can resist most chemical corrosion. In the field of electronics, ETP copper and OFE copper are common materials, both known for their outstanding electrical properties. Despite the high price volatility of copper, it finds widespread use in various applications.

Aluminum bus bar

Aluminum bus bars, as an alternative to copper, are becoming increasingly popular in electrical applications. Aluminum is much lighter than copper, with a density of approximately one-third that of copper, requiring a larger volume for the same weight.

While aluminum's conductivity is slightly lower than that of copper, its lower cost helps to save expenses and achieve lightweight designs in various fields. Aluminum bus bars generally have lower production and installation costs compared to copper, and in many cases, aluminum also exhibits good mechanical machining properties.

NO.1 Conductivity contrast: aluminum vs. copper busbar

Conductivity is one of the most crucial indicators for bus bar conductors. Typically, copper bus bars have a conductivity of up to 99.8% IACS, while the conductivity of aluminum bus bars varies slightly depending on the alloy. For instance, pure aluminum bus bars like 1350 typically have a conductivity of around 62% IACS, whereas 6101 aluminum bus bars usually exhibit a conductivity of approximately 55% IACS.

NO.2 Strength comparison: aluminum busbars vs. copper busbar

Strength is also a critical indicator for bus bars. Copper has a tensile strength of about 32,000 psi, while the tensile strength of electrical-grade aluminum alloy 6101 is approximately 28,000 psi.

NO.3 Resistance variation: copper busbars vs. aluminum busbar

Bus bar resistance is one of the critical performance indicators for bus bar conductors. Volume-wise, copper outperforms aluminum. Copper offers lower resistance, reduced power loss, decreased voltage drop, and higher current-carrying capacity, enhancing the electrical efficiency of bus bar systems.

NO.4 Current-carrying capacity: aluminum vs. copper busbar

Current carrying capacity refers to the maximum current that a bus bar can handle, determined by factors such as conductor material resistance, temperature rise, and mechanical strength.

In general, copper has a higher conductivity, resulting in a higher current carrying capacity for copper bus bars compared to aluminum bus bars of the same cross-sectional area. This means that under the same current load, copper bus bars experience relatively lower temperature rises, thus enhancing system stability and reliability.

Although the current carrying capacity of aluminum bus bars is lower than that of copper bus bars, they can still handle currents of up to 4000A, which is sufficient for many applications.

Comparison Table of Copper and Aluminum Ampacity
Ampacity Conversion Chart			Copper C110		30° C Rise	50° C Rise	65° C Rise	Aluminum 6101		30° C Rise	50° C Rise	65° C Rise
Flat Bar Size in Inches	Sq. In	Circ Mils Thousands	Weight Per Ft in Lb.	DC Resistance at 20° C, Microhms/Ft	60 Hz Ampacity Amp*			Weight Per Ft in Lb.	DC Resistance at 20° C, Microhms/Ft	60 Hz Ampacity Amp**
1/16 x 1/2	0.0312	39.7	0.121	264	103	136	157	0.037	494	58	76	88
1/16 x 3/4	0.0469	59.7	0.181	175	145	193	225	0.055	327	81	108	126
1/16 x 1	0.0625	79.6	0.242	132	187	250	285	0.073	247	105	140	160
1/16 x 1 1/2	0.0938	119	0.362	87.7	270	355	410	0.110	164	151	199	230
1/16 x 2	0.125	159	0.483	65.8	345	460	530	0.146	123	193	258	297
1/8 x 1/2	0.0625	79.6	0.241	132	153	205	235	0.073	247	86	115	132
1/8 x 3/4	0.0938	119	0.362	87.7	215	285	325	0.110	164	120	160	182
1/8 x 1	0.125	159	0.483	65.8	270	360	415	0.146	123	151	202	232
1/8 x 1 1/2	0.188	239	0.726	43.8	385	510	590	0.220	82	216	286	330
1/8 x 2	0.25	318	0.966	32.9	495	660	760	0.293	62	277	370	426
1/8 x 2 1/2	0.312	397	1.210	26.4	600	800	920	0.365	49	336	448	515
1/8 x 3	0.375	477	1.450	21.9	710	940	1100	0.439	41	398	526	616
1/8 x 3 1/2	0.438	558	1.690	18.8	810	1100	1250	0.512	35	454	616	700
1/8 x 4	0.5	636	1.930	16.5	900	1200	1400	0.585	31	504	672	784
3/16 x 1/2	0.09375	119	0.362	87.7	195	260	300	0.110	164	109	146	168
3/16 x 3/4	0.141	179	0.545	58.4	270	360	415	0.165	109	151	202	232
3/16 x 1	0.188	239	0.726	43.8	340	455	520	0.220	82	190	255	291
3/16 x 1 1/2	0.281	358	1.090	29.3	480	630	730	0.329	55	269	353	409
3/16 x 2	0.375	477	1.450	21.9	610	810	940	0.439	41	342	454	526
3/16 x 2 1/2	0.469	597	1.810	17.5	740	980	1150	0.549	33	414	549	644
3/16 x 3	0.562	715	2.170	14.6	870	1150	1350	0.658	27	487	644	756
3/16 x 3 1/2	0.656	835	2.530	12.5	990	1300	1500	0.768	23	554	728	840
3/16 x 4	0.75	955	2.900	11	1100	1450	1700	0.878	21	616	812	952
1/4 x 1/2	0.125	159	0.483	65.8	240	315	360	0.146	123	134	176	202
1/4 x 3/4	0.188	239	0.726	43.8	320	425	490	0.220	82	179	238	274
1/4 x 1	0.25	318	0.966	32.9	400	530	620	0.293	62	224	297	347
1/4 x 1 1/2	0.375	477	1.450	21.9	560	740	880	0.439	41	314	414	482
1/4 x 2	0.5	637	1.930	16.5	710	940	1100	0.585	31	398	526	616
1/4 x 2 1/2	0.625	796	2.410	13.2	850	1150	1300	0.731	25	476	644	728
1/4 x 3	0.75	955	2.900	11	990	1300	1550	0.878	21	554	728	868
1/4 x 3 1/2	0.875	1110	3.380	9.4	1150	1500	1750	1.024	18	644	840	980
1/4 x 4	1	1270	3.860	8.23	1250	1700	1950	1.170	15	700	952	1092
1/4 x 5	1.25	1590	4.830	6.58	1500	2000	2350	1.463	12	840	1120	1316
1/4 x 6	1.5	1910	5.800	5.49	1750	2350	2700	1.755	10	980	1316	1512
3/8 x 3/4	0.281	368	1.090	29.3	415	550	630	0.329	55	232	308	353
3/8 x 1	0.375	477	1.450	21.9	510	680	790	0.439	41	286	381	442
3/8 x 1 1/2	0.562	715	2.170	14.6	710	940	1100	0.658	27	398	526	616
3/8 x 2	0.75	955	2.900	11	880	1150	1350	0.878	21	493	644	756
3/8 x 2 1/2	0.938	1190	3.620	8.77	1050	1400	1600	1.097	16	5.88	784	896
3/8 x 3	1.12	1430	4.350	7.35	1200	1600	1850	1.310	14	672	896	1036
3/8 x 3 1/2	1.31	1670	5.060	6.38	1350	1800	2100	1.533	12	756	1008	1176
3/8 x 4	1.5	1910	5.8	5.49	1500	2000	2350	1.755	10	840	1120	1316
3/8 x 5	1.88	2390	7.26	4.38	1800	2400	2800	2.2	8	1008	1344	1568
3/8 x 6	2.25	2860	8.69	3.66	2100	2800	3250	2.633	7	1176	1568	1820
1/2 x 1	0.5	637	1.93	16.5	620	820	940	0.585	31	347	459	526
1/2 x 1 1/2	0.75	955	2.9	11	830	1100	1250	0.878	21	465	616	700
1/2 x 2	1	1270	3.86	8.23	1000	1350	1550	1.17	15	560	756	868
1/2 x 2 1/2	1.25	1590	4.83	6.58	1200	1600	1850	1.463	12	672	896	1036
1/2 x 3	1.5	1910	5.8	5.49	1400	1850	2150	1.755	10	784	1036	1204
1/2 x 3 1/2	1.75	2230	6.76	4.7	1550	2100	2400	2.048	9	868	1176	1344
1/2 x 4	2	2550	7.73	4.11	1700	2300	2650	2.34	8	952	1288	1484
1/2 x 5	2.5	3180	9.66	3.29	2050	2750	3150	2.925	6	1148	1540	1764
1/2 x 6	3	3820	11.6	2.74	2400	3150	3650	3.51	5	1344	1764	2044
1/2 x 8	4	5090	15.5	2.06	3000	4000	4600	4.68	4	1680	2240	2576

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Therefore, when designing power systems, it is necessary to consider the current carrying capacity of both copper and aluminum bus bars comprehensively. Based on specific application requirements, space limitations, and environmental conditions, selecting the appropriate material and size is crucial to ensure the safe and stable operation of the system.

NO.5 Connection methods: aluminum vs. copper busbar

Common connection methods for aluminum and copper bus bars include bolted connections, crimp connections, welded connections, plug-in connections, and soldered connections. Although the connection methods for both are similar, due to copper's better conductivity, copper bus bars can use smaller contact areas. When selecting a connection method, factors such as engineering requirements, construction conditions, technical specifications, and costs should be considered. It is essential to ensure that the surface is clean, the contact area is sufficiently large, and necessary tests are conducted to ensure a secure and reliable connection.

NO.6 Weight consideration: copper vs. aluminum busbar

The difference in weight between aluminum and copper bus bars mainly stems from their different densities. Copper has a density of approximately 8.96 grams per cubic centimeter, while aluminum has a density of about 2.7 grams per cubic centimeter. Therefore, copper bus bars of the same cross-sectional area weigh approximately 3.3 times more than aluminum bus bars. For example, a 100 square millimeter copper bus bar weighs around 8.9 kilograms, while an aluminum bus bar of the same cross-sectional area weighs around 2.7 kilograms. The choice between copper and aluminum bus bars depends on the specific requirements: copper bus bars are preferred when higher conductivity and thermal conductivity are needed, while aluminum bus bars are chosen to reduce weight. Click to calculcate the weight of aluminum bus bar.

NO.7 Cost analysis: copper busbars vs. aluminum busbar

There is a significant price difference between aluminum and copper bus bars, with copper being much more expensive than aluminum. Additionally, aluminum prices tend to be more stable compared to copper, with less influence from consumer demand and other political and economic factors. According to data from the London Metal Exchange, the current price ratio between copper and aluminum exceeds 2.6:1, indicating a substantial cost difference between them.

As a result, metal stockists and project managers often prefer aluminum bus bars when their performance requirements are met, as it allows for more accurate cost predictions, thus saving project expenses. The lightweight nature of aluminum bus bars also saves a considerable amount on transportation and installation costs, making them a more cost-effective choice in the design of power systems.

NO.8 Environmental impact: copper vs. aluminum busbar

There are some differences between aluminum and copper bus bars in terms of recyclability. Although both aluminum and copper are 100% recyclable metals, their recycling processes have varying degrees of environmental impact.

Aluminum is one of the most recycled industrial metals, with approximately 75% of recycled aluminum still in use. In contrast, the recycling rate for copper is slightly lower, at about 65%. Additionally, the energy required to recycle aluminum is only 5% of that needed for primary production, while recycling the same amount of copper requires 15% of the energy needed for mining and extraction. This indicates that the recycling process for aluminum has a smaller environmental impact, as it relies less on non-ecological mining and extraction processes and generates less energy waste.

In summary, aluminum bus bars have a relative advantage in recyclability, as their recycling process has a smaller environmental impact and helps conserve resources and reduce costs.

NO.9 Application specifics: choosing between copper and aluminum busbar

Aluminum bus bars are typically used in applications where cost and weight requirements are high, such as interior electrical systems in buildings, small industrial equipment, and low-voltage power distribution systems. Compared to copper bus bars, aluminum bus bars have lower density and cost. Therefore, in cost- and weight-sensitive applications, aluminum bus bars are often the more economical and suitable choice.

On the other hand, copper bus bars are commonly used in applications that require high electrical conductivity and reliability, such as large industrial equipment, substations, and high-voltage power distribution systems. Due to their lower resistance, excellent conductivity, and stability, copper bus bars can withstand higher current loads and maintain stable resistance and temperature rise over long-term use. Therefore, they are widely used in power systems with high-performance and stability requirements.

In summary, aluminum and copper bus bars play important roles in different application scenarios. Choosing the appropriate material depends on specific project requirements, performance criteria, and cost considerations.

Summarize

In summary, there are significant differences between aluminum and copper bus bars in terms of cost, weight, recyclability, and environmental friendliness. Aluminum bus bars have lower manufacturing costs, are lighter in weight, and have lower transportation and installation costs, but their conductivity is slightly lower than that of copper bus bars. On the other hand, copper bus bars, while more expensive and heavier, offer excellent conductivity and higher reliability.

Therefore, when choosing between aluminum and copper bus bars, it's essential to conduct a comprehensive assessment based on specific project requirements. If the project demands lower costs and weight with moderate conductivity requirements, then aluminum bus bars may be the more suitable choice. If the project requires high conductivity and reliability, with a higher budget, then copper bus bars might be more appropriate.

Taking into account project requirements, budget, performance criteria, and environmental factors, selecting the most suitable bus bar material is crucial for the successful implementation of the project.

Mastar Metal EC grade aluminum busbar product list